Search results for: vaccine preventable diseases

Authors: Jai Myung Yang, Na Young Kim, Sung Ho Shin

Abstract:

The adverse reactions of current live smallpox vaccines and potential use of smallpox as a bioterror weapon have heightened the development of new effective vaccine for this infectious disease. In the present study, DNA vaccine vector was produced which was optimized for expression of the vaccinia virus L1 antigen in the mouse model. A plasmid IgM-tL1R, which contains codon-optimized L1R gene, was constructed and fused with an IgM signal sequence under the regulation of a SV40 enhancer. The expression and secretion of recombinant L1 protein was confirmed in vitro 293 T cell. Mice were administered the DNA vaccine by electroporation and challenged with vaccinia virus. We observed that immunization with IgM-tL1R induced potent neutralizing antibody responses and provided complete protection against lethal vaccinia virus challenge. Isotyping studies reveal that immunoglobulin G2 (IgG2) antibody predominated after the immunization, indicative of a T helper type 1 response. Our results suggest that an optimized DNA vaccine, IgM-tL1R, can be effective in stimulating anti-vaccinia virus immune response and provide protection against lethal orthopoxvirus challenge.

Keywords: DNA vaccine, electroporation, L1R, vaccinia virus

Procedia PDF Downloads 266

Authors: Ahmed Zaghawa

Abstract:

Rift Valley Fever is an economically specific disease of the health and arboviral disease that affects many types of animals, causing significant economic losses in livestock, and it is transmitted to humans and has public health issues. The vaccine program is the backbone for the control of this disease. The goal of this study was to apply a new approach to evaluate the inactivated RVF vaccine developed in Egypt. In this study, the RVF vaccine was evaluated in young puppies and compared with sheep; the findings showed that young puppies were susceptible to infection with the inhibitory RVF virus and had a strong response of antibodies with two doses of the RVF vaccine within the two-week interval. The neutralization indices began to appear to the protective level on the 7th day at 1.35 and steadily elevated at 14,21 and 28 days to 1.35, 1.43, and 1.20, respectively, in comparison to the control group. While in sheep, the neutralization indices began to appear to the protective level on the 7th day at 1.10 and remain strongly at high titer at 14, 21, and 28 days with NI values 1.20, 1.50, and 1.50, respectively. The new approach for comparing the immune response in puppies and sheep via SNT indicated the high response in both species was evident as well as the neutralization indices values in young puppies at different periods after RVF vaccination reported the value of 1.08±0.03, 1.23±0.04, 1.30±0.03, and 1.45±0.02 after 7, 14, 21, and 28 days post-vaccination respectively. On the other side, a nearly similar immune response was noticed in sheep with NI values of 1.15±0.02, 1.27±0.02, 1.42±0.05, and 1.55±0.03 at 7, 14, 21, and 28 days post-vaccination, respectively. In conclusion, young puppies are similar to sheep in developing antibodies after vaccination with the RVF vaccine and can replace sheep for evaluating the efficacy of the RVF vaccine. Further studies are mandatory to assess more recent methods for evaluating inhibition of the RVF vaccine.

Keywords: immune response, puppies, RVF, sheep, vaccine

Procedia PDF Downloads 176

Authors: Yahia Massinissa, Melakhessou Med Akram, Mezahdia Mehdi, Marref Salah Eddine

Abstract:

Cytokines are natural proteins which act as true intercellular communication signals in immune and inflammatory responses. Reverse signaling pathways that activate cytokines help to regulate different functions at the target cell, causing its activation, its proliferation, the differentiation, its survival or death. It was shown that malfunctioning of the cytokine regulation, particularly over-expression, contributes to the onset and development of certain serious diseases such as chronic rheumatoid arthritis, Crohn's disease, psoriasis, lupus. The action mode of Kinoid® technology is based on the principle vaccine: The patient's immune system is activated so that it neutralizes itself and the factor responsible for the disease. When applied specifically to autoimmune diseases, therapeutic vaccination allows the body to neutralize cytokines (proteins) overproduced through a highly targeted stimulation of the immune system.

Keywords: cytokines, Kinoid tech, auto-immune diseases, vaccination

Procedia PDF Downloads 337

Authors: Ajit Kumar Yadav, Priyanka Yadav, F. Ram

Abstract:

In present study is an effort to analyse the burden of diseases in the state. Disability Adjusted Life Years (DALY) is estimated non-communicable diseases. Multi-rounds (52nd, 60th and 71st round) of the National Sample Surveys (NSSO), conducted in 1995-96, 2004 and 2014 respectively, and Million Deaths Study (MDS) of 2001-03, 2006 and 2013-14 datasets are used. Descriptive and multivariate analyses are carried out to identify the determinants of different types of self-reported morbidity and DALY. The prevalence was higher for population aged 60 and above, among females, illiterates, and rich across the time period and for all the selected morbidities. The results were found to be significant at P<0.001. The estimation of DALY revealed that, the burden of communicable diseases was higher during infancy, noticeably among males than females in 2002. However, females aged 1-5 years were more vulnerable to report communicable diseases than the corresponding males. The age distribution of DALY indicates that individuals aged below 5 years and above 60 year were more susceptible to ill health. The growing incidence of non-communicable diseases especially among the older generations put additional burden on the health system in the state. The state has to grapple with the unsettled preventable infectious diseases in one hand and growing non-communicable in other hand.

Keywords: disease burden, non-communicable, communicable, India and region

Procedia PDF Downloads 251

Authors: Farahnaz Motamedi Sedeh, Homayoon Mahravani, Parvin Shawrang, Mehdi Behgar

Abstract:

Most countries use inactivated binary ethylenimine (BEI) vaccines to control and prevent Foot-and-Mouth Disease (FMD). However, this vaccine induces a short-term humoral immune response in animals. This study investigated the cellular and humoral immune responses in homologous and prime-boost (PB) groups in the BALB/c mouse model. FMDV strain O/IRN/1/2007 was propagated in the BHK-21 cell line and inactivated by three methods, including a chemical with BEI to produce a conventional vaccine (CV), a gamma irradiation vaccine (GIV), and an electron irradiated vaccine (EIV). Three vaccines were formulated with the adjuvant aluminum hydroxide gel. In addition, a DNA vaccine was prepared by amplifying the virus VP1 gene pcDNA3.1 plasmid. In addition, the plasmid encoding the granulocyte-macrophage colony-stimulating factor gene (GM-CSF) was used as a molecular adjuvant. Eleven groups of five mice each were selected, and the vaccines were administered as homologous and heterologous strategy prime-boost (PB) in three doses two weeks apart. After the evaluation of neutralizing antibodies, interleukin (IL)-2, IL-4, IL-10, interferon-gamma (INF-γ), and MTT assays were compared in the different groups. The pcDNA3.1+VP1 cassette was prepared and confirmed as a DNA vaccine. The virus was inactivated by gamma rays and electron beams at 50 and 55 kGy as GIV and EIV, respectively. Splenic lymphocyte proliferation in the inactivated vaccinated homologous groups was significantly lower (P≤0.05) compared with the heterologous prime-boosts (PB1, PB2, PB3) and DNA + GM-CSF groups (P≤0.05). The highest SNT titer was observed in the inactivated vaccine groups. IFN-γ and IL-2 were higher in the vaccinated groups. It was found that although there was a protective humoral immune response in the groups with inactivated vaccine, there was adequate cellular immunity in the group with the DNA vaccine. However, the strongest cellular and humoral immunity was observed in the PB groups. The primary injection was accompanied by DNA vaccine + GM-CSF and boosted injection with GIV or CV.

Keywords: foot and mouth disease, irradiated vaccine, immune responses, DNA vaccine, prime boost strategy

Procedia PDF Downloads 16

Authors: Ghassen Kharroubi, Ines Cherif, Leila Bouabid, Adel Gharbi, Aicha Boukthir, Margaret McCarron, Nissaf Ben Alaya, Afif Ben Salah, Jihene Bettaieb

Abstract:

Influenza vaccination (IV) is recommended for elderly persons, especially those with underlying conditions. In countries where IV rates in the elderly remain unsatisfactory, exploring attitudes of older persons toward the flu vaccine could be useful to identify barriers and facilitators to IV. The aim of this study was to determine the reasons for IV acceptance or decline in the Tunisian elderly. A national cross-sectional study was conducted in 2019, among persons aged 60 years and over with chronic disease. Data were collected using a standard administered questionnaire. Of the 1191 older persons included, 19.4% received the influenza vaccine in the 2018-2019 flu season. The two main reasons that may lead to refusal of vaccination were concerns that the vaccine could cause side effects (71.5%) and a belief that the vaccine was ineffective (33.9%). The main reason that may lead to accepting vaccination was a doctor’s recommendation (41.1%). Doctors were by far the most trusted source for information regarding influenza vaccine (91.5%) followed by pharmacists (17.6%). Our results highlighted the important role that doctors could play in promoting IV among the Tunisian elderly. Physicians should correct misconceptions about adverse events and the efficiency of the vaccine. In fact, influenza vaccines are generally effective and safe among older persons.

Keywords: attitudes, influenza vaccination, older persons, Tunisia

Procedia PDF Downloads 152

Authors: Jacinta Musyoka, Wesley Too

Abstract:

Cervical cancer is the second leading cause of cancer-related deaths in Kenya and the second most common cancer among women, yet preventable following prevention strategies put in place, which includes vaccination with Human Papilloma Virus Vaccine (HPPV) among the young adolescent girls. Kenya has the highest burden of cervical cancer and the leading cause of death among women of reproductive age and is a known frequent type of cancer amongst women. This is expected to double by 2025 if the necessary steps are not taken, which include vaccinating girls between the ages of 9 and 14 and screening women. Parental decision is critical in ensuring that their daughters receive this vaccine. Hence this study sought to establish parental willingness and factors associate with the acceptability to vaccine adolescent daughters against the human papilloma virus for cervical cancer prevention in Machakos County, Eastern Region of Kenya. Method: Cross-sectional study design utilizing a mixed methods approach was used to collect data from Nguluni Health Centre in Machakos County; Matungulu sub-county, Kenya. This study targeted all parents of adolescent girls seeking health care services in the Matungulu sub-county area who were aged 18 years and above. A total of 220 parents with adolescent girls aged 10-14 years were enrolled into the study after informed consent were sought. All ethical considerations were observed. Quantitative data were analyzed using Multivariate regression analysis, and thematic analysis was used for qualitative data related to perceptions of parents on HPVV. Results, conclusions, and recommendations- ongoing. We expect to report findings and articulate contributions based on the study findings in due course before October 2022

Keywords: adolescents, human papilloma virus, kenya, parents

Procedia PDF Downloads 109

Authors: Farina Maqbool

Abstract:

Background: It is well said that children are considered the future masons of the country and a healthy brain is found in a healthy body. Therefore, a healthy generation can be produced by giving knowledge of immunization to mothers. Immunization is the most lucrative public health intrusion that has placed the greatest effect on the health of the people. The main objective of the present study was to find out the mother’s knowledge, attitude, and practices towards childhood immunization. Methods: Multistage sampling technique was used. One hundred and sixty mothers were selected conveniently who have at least one child up to two years. Data were collected through the face to face interview. The chi-square test was used to test the significance of the association between independent and dependent variables. Data were analyzed using the Statistical Package for Social Science. Results: A higher percentage of mothers (85.0%) knew vaccine-preventable diseases. Major proportion (82.5%) of the mothers had thought that immunization is important for their child’s health. A majority (66.3%) of the respondents’ children were fully immunized, whereas 26.3 percent of them were replied negatively. Remaining 7.5 percent of the respondents’ child un-immunized Chi-square value (39.14) shows a highly significant association between the education of the respondents and receiving of all recommended vaccines for children. Gamma value shows a strong positive relationship between the variables.

Keywords: attitude, childhood, immunization, knowledge, practices

Procedia PDF Downloads 141

Authors: N. Othman, J. Ujang, M. N. Ismail, R. Noordin, B. H. Lim

Abstract:

Amoebiasis is caused by the Entamoeba histolytica and still endemic in many parts of the tropical region, worldwide. Currently, there is no available vaccine against amoebiasis. Hence, there is an urgent need to develop a vaccine. The excretory secretory antigen (ESA) of E. histolytica is a suitable biomarker for the vaccine candidate since it can modulate the host immune response. Hence, the objective of this study is to identify the proteome of the ESA towards finding suitable biomarker for the vaccine candidate. The non-gel based and gel-based proteomics analyses were performed to identify proteins. Two kinds of mass spectrometry with different ionization systems were utilized i.e. LC-MS/MS (ESI) and MALDI-TOF/TOF. Then, the functional proteins classification analysis was performed using PANTHER software. Combination of the LC -MS/MS for the non-gel based and MALDI-TOF/TOF for the gel-based approaches identified a total of 273 proteins from the ESA. Both systems identified 29 similar proteins whereby 239 and 5 more proteins were identified by LC-MS/MS and MALDI-TOF/TOF, respectively. Functional classification analysis showed the majority of proteins involved in the metabolic process (24%), primary metabolic process (19%) and protein metabolic process (10%). Thus, this study has revealed the proteome the E. histolytica ESA and the identified proteins merit further investigations as a vaccine candidate.

Keywords: E. histolytica, ESA, proteomics, biomarker

Procedia PDF Downloads 343

Authors: Ali Saeed Alghamdi, Basel Mazen Alsolami, Basel Saeed Alghamdi, Muhanad Saleh Alzahrani Alamri, Salman Anwar Thabet, Abdulhalim J. Kinsara

Abstract:

Objectives: This study measures the knowledge of the cardiovascular disease among the general population in western regions of Saudi Arabia, and it aimed to increase the level of awareness about cardiovascular diseases among the general population by providing an awareness lecture that included information about the risk factors, major symptoms, and prevention of cardiovascular diseases. The lecture has been attached at the end of the questionnaire. Setting: This study was conducted through an online questionnaire that included our aim and main objectives that targeted the general population in the Western regions of Saudi Arabia (Makkah and Madinah regions). Participants: This study participants were 460 collected through an online questionnaire. Methods: All Saudi citizens and residents who live in the western region of Saudi Arabia aged 18 years and above will be invited to participate voluntarily. A pre-structured questionnaire was designed to collect data on age, gender, marital status, education level, occupation, lifestyle habits, and history of heart diseases, with cardiac symptoms and risk factors sections. Results: The majority of respondents were females (74.8%) and Saudis. The knowledge about cardiovascular disease risk factors was weak. Only (18.5%) scores an excellent response regarding risk factors awareness. Lack of exercise, stress, and obesity were the most known risk factors. Regarding cardiovascular disease symptoms, chest pain scores the highest symptom (87.6%) among other symptoms like dyspnea, syncope, and excessive sweating. Participants revealed a poor awareness regarding cardiovascular disease symptoms also (0.9%). However, preventable factors for cardiovascular diseases were more knowledgeable than others categories in this study (60% fall into excellent knowledge). Smoking cessation, normal cholesterol level, and normal blood pressure score the highest preventable methods (92.2%), (88.6%), and (78.7%) respectively. 83.7% of the participant have attended the awareness lecture, and 99 of the attendees reported that the lecture increased their knowledge about cardiovascular disease. Conclusion: This study discussed the level of community awareness of cardiovascular disease in terms of symptoms, risk factors, and protective factors. We found a huge lack of the participant's level of knowledge about the disease and how to prevent it. Moreover, we measure the prevalence of the comorbidities among our participants (diabetes, hypertension, hypercholesterolemia/ hypertriglyceridemia) and their extent of adherence to their medication. In conclusion, this study not only demonstrates awareness of cardiovascular disease risk factors, symptoms, management, and the association between each domain but also provides educational material. Further educational material and campaigns are required to increase awareness and knowledge about cardiovascular diseases.

Keywords: awareness, cardiovascular diseases, education, prevention, risk factors

Procedia PDF Downloads 131

Authors: Muhammad Imran Nisar, Fyezah Jehan, Tauseef Akhund, Sadia Shakoor, Kanwal Nayani, Furqan Kabir, Asad Ali, Anita Zaidi

Abstract:

Pneumococcal Vaccine -10 (PCV 10) was included in the Expanded Program of immunization (EPI) in Sindh, Pakistan in February 2013. This study was carried out immediately before the introduction of PCV 10 to establish baseline pneumococcal carriage and prevalent serotypes in naso-pharynx of children 3-11 months of age in an urban and rural community in Sindh, Pakistan. An additional sample of children aged 12 to 59 months was drawn from the urban community. Nasopharyngeal specimens were collected from a random sample of children. Samples were processed in a central laboratory in Karachi. Pneumococci were cultured on 5% Sheep Blood Agar and serotyping was performed using CDC standardized sequential multiplex PCR assay on bacterial colonies. Serotypes were then categorized into vaccine (PCV-10 and PCV-13) type and non-vaccine types. A total of 670 children were enrolled. Carriage rate for pneumococcus based on culture positivity was 74% and 79.5 % in the infant group in Karachi and Matiari respectively. Carriage rate was 78.2% for children aged 12 to 59 months in Karachi. Proportion of PCV 10 serotypes in infants was 38.8% and 33.5% in Karachi and Matiari respectively. In the older age group in Karachi, the proportion was 30.6%. Most common serotypes were 6A, 6B, 23F, 19A and 18C. This survey establishes vaccine and non-vaccine serotype carriage rate in a vaccine-naïve pediatric population among rural and urban communities in Sindh province. Annually planned surveys in the same communities will inform change in carriage rate after the introduction and uptake of PCV 10 in these communities.

Keywords: Naso-Pharyngeal carriage, Pakistan, PCV10, Pneumococcus

Procedia PDF Downloads 300

Authors: Mohammed E. Mansour, Tamador M. A. Elhassan, Nahid A. Ibrahim, Awatif A. Ahmed, Manal A. Abdalla

Abstract:

Rift valley fever (RVF) is mosquito-borne disease. RVF is transboundary zoonotic disease. It has socioeconomic and public health importance. This paper describes qualitative risk of the RVF vaccine production. RVF is endemic in the Sudan. It has been reported in Sudan due to abundance of Ades Eqytie. Thus, there is huge effort to control it. Vaccination practices had significant role to control and manage RVF. The risk assessment explains the likelihood of a risk as likely. Thus, insecticides and repellents synergize the effort of the vaccination.

Keywords: qualitative analysis, risk assessment, rift valley fever vaccine, quality control

Procedia PDF Downloads 512

Authors: Celestine Odigwe, Epoke Lincoln, Rhoda-Dara Ephraim

Abstract:

Background; Immunization against the childhood killer diseases is the cardinal strategy for the prevention of these diseases all over the world in under five children, these diseases include; Tuberculosis, Measles, Polio, Tetanus, Diphthria, Pertusis, Yellow Fever, Hepatitis B, Haemophilus Influenza type B. 6.9 million children die before their fifth birthday , 80% of the worlds death in children under 5 years occur in 25 countries most in Africa and Asia and 2 million children can be saved each year with routine immunization Therefore failure to achieve total immunization coverage puts several children at risk. Aim; The aim of the study was to ascertain the prevalence, Investigate the various reasons and causes why several under five children in a suburb of calabar municipal county fail to get the required immunizations as at and when due and possibly the consequences, so that efforts can be re-directed towards the solution of the problems so identified. Methods; the study was a community based cross sectional study. The respondents were the mothers/guardians of the sampled children who were all aged 0-59 months. To be eligible for recruitment into the study, the parent or guardian was required to give an informed consent, reside within the Calabar South County with his/her children aged 0-59 months. We calculated our sample size using the Leslie-Kish formula and we used a two-staged sampling method, first to ballot for the wards to be involved and then to select four of the most populated ones in the wards chosen. Data collection was by interviewer administered structured questionnaire (Appendix I), Data collected was entered and analyzed using Statistical Package for the Social Sciences (SPSS) Version 20. Percentages were calculated and represented using charts and tables Results; The number of children sampled was 159. We found that 150 were fully immunized and 9 were not, the prevalence of missed opportunity was 32% from the study. The reasons for missed opportunities were varied, ranging from false contraindications, logistical problems resulting in very poor access roads to health facilities and poor organization of health centers together with negative health worker attitudes. Some of the consequences of these missed opportunities were increased susceptibility to vaccine preventable diseases, resurgence of the above diseases and increased morbidity and mortality of children aged less than 5 years. Conclusion; We found that ignorance on the part of both parents/guardians and health care staff together with infrastructural inadequacies in the county such as- roads, poor electric power supply for storage of vaccines were hugely responsible for most missed opportunities for immunization. The details of these and suggestions for improvement and the way forward are discussed.

Keywords: missed opportunity, immunization, under five, Calabar south

Procedia PDF Downloads 324

Authors: Huijun Wu

Abstract:

The COVID-19 pandemic has caused massive negative shocks across countries. Various research institutes have worked assiduously to develop vaccines to help fight the pandemic, but misinformation from the media has spurred public outcry in several countries not to take jabs. This study leverages massive data [i.e., responses from more than 140,000 people sampled from 144 countries] extracted from the Gallup World Poll’s Wellcome Global Monitor, to analyze and assess how the media contributes to inadequate dissemination of basic scientific knowledge on the vaccines and spread of distrust in central governments as predictors of vaccine hesitancy. The results show that all three predictors are statistically significant at a 5% level and that appropriate design and dissemination of basic scientific knowledge on the vaccines and spread of justified reasons to trust governments would help mitigate vaccine hesitancy. The implication of the results is that the media needs to consider such predictors hitherto ignored.

Keywords: COVID-19 pandemic, vaccine hesitancy, media and communication, basic scientific knowledge, distrust in central governments

Procedia PDF Downloads 180

Authors: Alyaa Abdlwahab

Abstract:

Cutaneous leishmaniasis represents a serious health problem in Syria; this problem has become noticeably aggravated after the civil war in the country. Leishmania tropica parasite is the main cause of cutaneous leishmaniasis in Syria. In order to control the disease, we need an effective vaccine against leishmania parasite. DNA vaccination remains one of the favorable approaches that have been used to face cutaneous leishmaniasis. Ribosomal protein S4 is responsible for important roles in Leishmania parasite life. DNA vaccine based on S4 gene has been used against infections by many species of Leishmania parasite but leishmania tropica parasite, so this gene represents a good candidate for DNA vaccine construction. After proving the existence of ribosomal protein S4 gene in a Syrian strain of Leishmania tropica (LCED Syrian 01), sequencing it and cloning it into pCI plasmid, BALB/C mice were inoculated with pCI-S4 DNA vaccine. The immune response was determined by monitoring the lesion progression in inoculated BALB/C mice for six weeks after challenging mice with Leishmania tropica (LCED Syrian 01) parasites. IL-12, IFN-γ, and IL-4 were quantified in draining lymph nodes (DLNa) of the immunized BALB/C mice by using the RT-qPCR technique. The parasite burden was calculated in the final week for the footpad lesion and the DLNs of the mice. This study proved the existence and the expression of the ribosomal protein S4 gene in Leishmania tropica (LCED Syrian 01) promastigotes. The sequence of ribosomal protein cDNA S4 gene was determined and published in Genbank; the gene size was 822 bp. Expression was also demonstrated at the level of cDNA. Also, this study revealed that pCI-S4 DNA vaccine induces TH1\TH2 response in immunized mice; this response prevents partially developing a dermal lesion of Leishmania.

Keywords: ribosomal protein S4, DNA vaccine, Leishmania tropica, BALB\c

Procedia PDF Downloads 136

Authors: Aneta Nitsch-Osuch, Katarzyna Zycinska, Ewa Gyrczuk, Agnieszka Topczewska-Cabanek, Kazimierz Wardyn

Abstract:

Introduction: Influenza is an important clinical and epidemiological problem and should be considered as a possible nosocomial infection. The aim of the study was to determine the influenza vaccine coverage rates among Polish nurses and to find out drivers and barriers for influenza vaccination among this group of health care workers (HCWs). Material and methods: The self- fulfilled survey with 26 questions about the knowledge, perception, and influenza coverage rates was distributed among 461 nurses. Results: Only 15% of nurses were vaccinated against influenza in the consecutive seasons. The majority (75%) of the regularly vaccinated nurses were ambulatory careworkers. The difference between the number of vaccinated hospitals and ambulatory care nurses was statistically significant (p < 0.05). The main motivating factors for an influenza vaccination were: a fear of the illness and its complications (97%) and a free of charge vaccine available at the workplace (87%). Ambulatory care nurses more often declared that they were vaccinated mainly to protect themselves while hospital care nurses more often declared the will to protect their patients, these differences in the perception and attitudes to an influenza vaccination among hospital and ambulatory care nurses were statistically significant (p < 0.05). The main barriers for an influenza vaccination among the nursing staff were: a lack of reimbursement of the vaccine (95%), a lack of insufficient knowledge about the effectiveness, and safety of the influenza vaccine (54%). The ambulatory care nurses more often found influenza vaccination as the ethical duty compared to hospital care nurses (p < 0.05). Conclusions: The influenza vaccine coverage rates among the Polish nurses are low and must be improved in the future. More educational activities dedicated to HCWs may result in the increased awareness of influenza vaccination benefits for both medical professionals and patients.

Keywords: influenza, vaccination, nurses, ambulatory careworkers

Procedia PDF Downloads 298

Authors: Aneta Nitsch-Osuch, Sylwia Dyk, Izabela Gołebiak

Abstract:

Background. Since 2014 the pertussis vaccine is recommended to Polish health care workers who have close contacts with infants. Although this recommendation is implemented into the National Immunization Programme, its realization has remained unknown. The Purpose: The aim of the study, conducted at the department of Social Medicine and Public Health (Medical University of Warsaw, Poland), was to describe a perception, knowledge and coverage rates regarding pertussis vaccination among nursing staff. According to the authors' knowledge, it was the first study related to this topic in our country. Material and Methods: A total number of 543 nurses who work at pediatric or neonatal wards was included into the study (501 women and 42 men), average age was 47 years. All nurses were asked to fulfill the anonymous survey, previously validated. Results: 1. Coverage rates: The analysis of results revealed that only 4% of responders reported they were vaccinated with Tdpa within past 10 years, while 8% declared they would plan the vaccine in the future. 35% of responders would consider the Tdpa vaccine whether there is some kind of the reimbursement. 2. Perception and knowledge of the disease and vaccination: The majority (82%) of nurses did not recognize pertussis as a re-emerging infectious disease. 54% of them believed that obligatory vaccinations in the childhood protect against the disease and the protection is a life-long one. Only 15% of nurses considered pertussis as a possible nosocomial infection. The current epidemiology of the disease was known to 6% of responders, while 24% of them were familiar with pertussis vaccination schedules for infants, children and adolescents, but only 9% of responders knew that adults older than 19 years are recommended to be vaccinated with Tdpa every 10 years. Many nurses (82%) would expect more educational activities related to pertussis and methods of its prophylaxis. Conclusions: The pertussis vaccine coverage rate among Polish nurses is extremely low. This is a result of not enough knowledge about the disease and its prevention. Educational activities addressed to health care workers and reimbursement of the pertussis vaccine are required to improve awareness and increase of vaccine coverage rates in the future.

Keywords: coverage, nurse, pertussis, vaccine

Procedia PDF Downloads 215

Authors: Antonia Egli, Theo Lynn, Pierangelo Rosati, Gary Sinclair

Abstract:

The World Health Organization (WHO) defines vaccine hesitancy as the postponement or complete denial of vaccines and estimates a direct linkage to approximately 1.5 million avoidable deaths annually. This figure is not immune to public health developments, as has become evident since the global spread of COVID-19 from Wuhan, China in early 2020. Since then, the proliferation of influential, but oftentimes inaccurate, outdated, incomplete, or false vaccine-related information on social media has impacted hesitancy levels to a degree described by the WHO as an infodemic. The COVID-19 pandemic and related vaccine hesitancy levels have in 2022 resulted in the largest drop in childhood vaccinations of the 21st century, while the prevalence of online stigma towards vaccine hesitant consumers continues to grow. Simultaneously, a second disease has risen to global importance: Monkeypox is an infection originating from west and central Africa and, due to racially motivated online hate, was in August 2022 set to be renamed by the WHO. To better understand public reactions towards two viral infections that became global threats to public health no two years apart, this research examines user replies to threads published by the WHO on Twitter. Replies to two Tweets from the @WHO account declaring COVID-19 and Monkeypox as ‘public health emergencies of international concern’ on January 30, 2020, and July 23, 2022, are gathered using the Twitter application programming interface and user mention timeline endpoint. Research methodology is unique in its analysis of stigmatizing, racist, and hateful content shared on social media within the vaccine discourse over the course of two disease outbreaks. Three distinct analyses are conducted to provide insight into (i) the most prevalent topics and sub-topics among user reactions, (ii) changes in sentiment towards the spread of the two diseases, and (iii) the presence of stigma, racism, and online hate. Findings indicate an increase in hesitancy to accept further vaccines and social distancing measures, the presence of stigmatizing content aimed primarily at anti-vaccine cohorts and racially motivated abusive messages, and a prevalent fatigue towards disease-related news overall. This research provides value to non-profit organizations or government agencies associated with vaccines and vaccination programs in emphasizing the need for public health communication fitted to consumers' vaccine sentiments, levels of health information literacy, and degrees of trust towards public health institutions. Considering the importance of addressing fears among the vaccine hesitant, findings also illustrate the risk of alienation through stigmatization, lead future research in probing the relatively underexamined field of online, vaccine-related stigma, and discuss the potential effects of stigma towards vaccine hesitant Twitter users in their decisions to vaccinate.

Keywords: social marketing, social media, public health communication, vaccines

Procedia PDF Downloads 98

Authors: Muhammad Fiaz Qamar, Ahmad Faraz, Muhammad Arfan Zaman, Kazim Ali, Waleed Akram

Abstract:

Babesiosis is reflected as the most important disease of cattle that are transmitted by arthropods. In Pakistan, its prevalence is up to 29% in the cattle and buffalo population in different regions. Cattle show a long lasting and durable immunity by giving an infection of B.bovis, B. bigemina, or Babesiadivergens. this is used in cattle to immunize them in a few countries as anti-babesiosis vaccine. Development of frozen vaccine allows for complete testing after production of each batch, However, once thawed, its reduced its shelf life, frozen vaccines are more difficult to transport as well as expensive to produce as compared to chilled vaccine. The contamination of blood derived vaccine has the potential risk that makes pre-production and post-production quality control necessary. For the trail master seed production of whole blood frozen bivalent Babesia(Babesiabovis and Babesiabigemina), 100 blood samples of Babesial positive suspected cattle was taken and processed for separation microscopic detection and rectification by PCR. Vaccine passages were done to reduce the parasitaemiasis in live calves. After 8 passages, parasitemia of Babesia reduced from 80% to 15%. Infected donor calf’s blood was taken by jugular cannulation by using preservative free lithium heparin as an anticoagulant (5 International Units IU heparin/ml blood). In lab, parasite containing blood was mixed in equal volumes with 3 M glycerol in PBS supplemented with 5 mM glucose (final concentration of glycerol 1.5 M) at 37°C. The mixture was then equilibrized at 37°C for 30 minutes and were dispensed in required containers (e.g., 5 ml cryovials).

Keywords: distribution, babesia, primer sequences, PCV

Procedia PDF Downloads 104

Authors: Pattanapon Kayansamruaj, Ha Thanh Dong, Nopadon Pirarat, Channarong Rodkhum

Abstract:

Streptococcus iniae (SI) is a devastating pathogenic bacteria causing heavy mortality in farmed fish. The application of commercialized bacterin vaccine has been reported failures as the outbreaks of the new serotype of SI were emerged in farms after vaccination and subsequently caused severe losses. In the present study, we attempted to develop effective DNA vaccines against SI infection using Nile tilapia (Oreochromis niloticus) as an animal model. Two monovalent DNA vaccines were constructed by the insertion of coding sequences of cell wall-associated virulence factors-encoding genes, comprised of eno (α-enolase) and mtsB (hydrophobic membrane protein), into cytomegalovirus expression vector (pCI-neo). In the animal trial, 30-g Nile tilapia were injected intramuscularly with 15 µg of each vaccine (mock vaccine group was injected by naked pCI-neo) and maintained for 35 days prior challenging with pathogenic SI at the dosage of 107 CFU/fish. At 13 days post-challenge, the relative percent survival of pEno, pMtsB and mock vaccine were 57%, 45% and 27%, respectively. The expression levels of immune responses-associated genes, namely, IL1β, TNF-α, TGF-β, COX2, IL-6, IL-12 and IL-13, were investigated from the spleen of experimental animal at 7 days post-vaccination (PV) and 7 days post-challenge (PC) using quantitative RT-PCR technique. Generally, at 7 days PV, the pEno vaccinated group exhibited highest level of up-regulation (1.7 to 2.9 folds) of every gene, but TGF-β, comparing to pMtsB and mock vaccine groups. However, at 7 days PC, pEno group showed significant up-regulation (1.4 to 8.5 folds) of immune-related genes as similar as mock vaccine group, while pMtsB group had lowest level of up-regulation (0.7 to 3.3 folds). Summarily, this study indicated that the pEno and pMtsB vaccines could elicit the immune responses of the fish and the magnitude of gene expression at 7 days PV was also consistent with the protection level conferred by the vaccine.

Keywords: gene expression, DNA vaccine, Nile tilapia, Streptococcus iniae

Procedia PDF Downloads 329

Authors: Claire Xu, Welton Wang, Manasvi Pinnaka, Anqi Pan, Michael Han

Abstract:

Hospitalizations account for one-third of the total health care spending in the US. Early risk detection and intervention can reduce this high cost and increase the satisfaction of both patients and physicians. Due to the lack of awareness of the potential arising risks in home environment, the opportunities for patients to seek early actions of clinical visits are dramatically reduced. This research aims to offer a highly personalized remote patients monitoring and risk assessment AI framework to identify the potentially preventable hospitalization for both acute as well as chronic diseases. A hybrid-AI framework is trained with data from clinical setting, patients surveys, as well as online databases. 20+ risk factors are analyzed ranging from activities, biometric info, demographic info, socio-economic info, hospitalization history, medication info, lifestyle info, etc. The AI model yields high performance of 87% accuracy and 88 sensitivity with 20+ features. This hybrid-AI framework is proven to be effective in identifying the potentially preventable hospitalization. Further, the high indicative features are identified by the models which guide us to a healthy lifestyle and early intervention suggestions.

Keywords: hospitalization prevention, machine learning, remote patient monitoring, risk prediction

Procedia PDF Downloads 230

Authors: Supanan Chansap, Werachon Cheukamud, Pornanan Kueakhai, Narin Changklungmoa

Abstract:

Fasciola species (Fasciola spp.) is caused fasciolosis in ruminants such as cattle, sheep, and buffalo. Fasciola gigantica (F.gigantica) commonly infects tropical regions. Fasciola hepatica (F.hepatica) in temperate regions. Liver fluke infection affects livestock economically, for example, reduced milk and meat production, weight loss, sterile animals. Currently, Triclabendazole is used to treat liver flukes. However, liver flukes have also been found to be resistant to drugs in countries. Therefore, vaccination is an attractive alternative to prevent liver fluke infection. Peptide vaccines are new vaccine technologies that mimic epitope antigens that trigger an immune response. An interesting antigen used in vaccine production is catepsin L, a family of proteins that play an important role in the life of the parasite in the host. This study aims to identify immunogenic regions of protein and construct a multi-epidetope vaccine using an immunoinformatic tool. Fasciola gigantica Cathepsin L1 (FgCatL1), Fasciola gigantica Cathepsin L1G (FgCatL1G), and Fasciola gigantica Cathepsin L1H (FgCatL1H) were predicted B-cell and Helper T lymphocytes (HTL) by Immune Epitope and Analysis Resource (IEDB) servers. Both B-cell and HTL epitopes aligned with cathepsin L of the host and Fasciola hepatica (F. hepatica). Epitope groups were selected from non-conserved regions and overlapping sequences with F. hepatica. All overlapping epitopes were linked with the GPGPG and KK linker. GPGPG linker was linked between B-cell epitope. KK linker was linked between HTL epitope and B-cell and HTL epitope. The antigenic scores of multi-epitope peptide vaccine was 0.7824. multi-epitope peptide vaccine was non-allergen, non-toxic, and good soluble. Multi-epitope peptide vaccine was predicted tertiary structure and refinement model by I-Tasser and GalaxyRefine server, respectively. The result of refine structure model was good quality that was generated by Ramachandran plot analysis. Discontinuous and linear B-cell epitopes were predicted by ElliPro server. Multi-epitope peptide vaccine model was two and seven of discontinuous and linear B-cell epitopes, respectively. Furthermore, multi-epitope peptide vaccine was docked with Toll-like receptor 2 (TLR-2). The lowest energy ranged from -901.3 kJ/mol. In summary, multi-epitope peptide vaccine was antigenicity and probably immune response. Therefore, multi-epitope peptide vaccine could be used to prevent F. gigantica infections in the future.

Keywords: fasciola gigantica, Immunoinformatic tools, multi-epitope, Vaccine

Procedia PDF Downloads 78

Authors: Maitri Dave

Abstract:

Coronaviruses (CoV) is such infectious virus which has impacted globally in a more dangerous manner causing severe lung problems and leaving behind more serious diseases among the people. This pandemic has affected globally and created severe respiratory problems, and damaged the lungs. India has reported the first case of COVID-19 in January 2020. The first wave of COVID-19 took place from April to September of 2020. Soon after, a second peak is also noticed in the month of March 2021, which in turn becomes more dangerous due to a lack of supply of medical equipment. It created resource deficiency globally, specifically in India, where some necessary life-saving equipment like ventilators and oxygenators were not sufficient to cater to the demand-supply ratio effectively. Through carefully examining such a situation, India began to execute the process of vaccination in the month of January 2021 and successfully administered 25,46,71,259 doses of vaccines till now, which is only 15.5% of the total population while only 3.6% of the total population is fully vaccinated. India has authorized the British Oxford–AstraZeneca vaccine (Covishield), the Indian BBV152 (Covaxin) vaccine, and the Russian Sputnik V vaccine for emergency use. In the present study, we have collected all the data state wisely of both first and second wave and analyzed them using MS Excel Version 2019 and SPSS Statistics Version 26. Following the trends, we have predicted the characteristics of the upcoming third wave of COVID-19 and recommended some strategies, early actions, and measures that can be taken by the public health system in India to combat the third wave more effectively.

Keywords: COVID-19, vaccination, Covishiled, Coronavirus

Procedia PDF Downloads 216

Authors: Ines Cherif, Ghassen Kharroubi, Leila Bouabid, Adel Gharbi, Aicha Boukthir, Margaret Mccarron, Nissaf Ben Alaya, Afif Ben Salah, Jihene Bettaieb

Abstract:

Healthcare workers' flu vaccination prevents influenza disease among both patients and caregivers. We aimed in this study to assess influenza vaccine (IV) coverage in 2018-2019 among Tunisian physicians and to determine factors associated with IV receipt. A cross sectional study was carried out in Tunisian primary and secondary health care facilities in the 2018-2019 influenza season. Physicians with direct patient contact were recruited according to a self-weighted multistage sampling. Data were collected through a face to face questionnaire containing questions on knowledge, attitudes, and practices regarding IV. Bivariate analysis was used in order to determine factors associated with IV receipt. A total of 167 physicians were included in the study with a mean age of 48.2 ± 7.7 years and a sex-ratio (M: F) of 0.37. Among participants, 15.1% (95% CI: [9.7%-20.3%]) were vaccinated against influenza in the 2018-2019 influenza season. Bivariate analysis revealed that previous flu immunization in the four years preceding the 2018-2019 influenza season (OR=32.3; p < 10-3), belief that vaccinating healthcare workers may reduce work absenteeism (OR=4.7, p=0.028), belief that flu vaccine should be mandatory to healthcare workers (OR=3.3, p=0.01) and high confidence towards IV efficacy in preventing influenza among caregivers (OR= 4.5, p=0.01) were associated with a higher IV receipt in 2018-2019 among physicians. Less than one fifth of Tunisian physicians were vaccinated against influenza in 2018-2019. Higher vaccine uptake was related to a higher belief in vaccine efficacy in preventing influenza disease among both patients and caregivers. This underscores the need for periodic educational campaigns to raise physicians' awareness about IV efficacy. The switch to an IV mandatory policy should also be considered.

Keywords: influenza vaccine, physicians, Tunisia, vaccination uptake

Procedia PDF Downloads 136

Authors: Ali Faisal Saleem, Farheen Quadri, Mach Ondrej, Anita Zaidi

Abstract:

Purpose: Pakistan is the final frontier for a polio-free world. Chronic malnutrition is associated with lack of effective gut immunity, and possibly associated with poliomyelitis in children received multiple OPV. We evaluate IPV dose administered together with OPV results in higher immunogenicity and mucosal immunity compared to OPV alone in chronically malnourished infants. Methods AND Materials: A community-based, unblinded-randomized-trial, conducted in 5 peri-urban, low-middle-income households of Karachi, in infants 9-12 months. Two study groups were non-malnourished (HAZ= -2 or more) and chronic malnourished (HAZ <-2SD), with 2-arms each i) OPV and ii) OPV and IPV. Two blood specimens (2ml) at baseline and at day 28 and two stool specimens (6 gm.) at day 29 and after 7 days. All infants received a bOPV challenge dose after first stool specimen. Calculates sample size was 210 in each arm. Serological (baseline compared to 28 days post-vaccine) and mucosal immunity after one week of bOPV challenge dose were study outcomes. Results: Baseline seroprevalence in malnourished infants were low compared to non-malnourished (P1, P2 and P3 (p=<0.001). There is significant rise in antibody titer and P1 seroprevalence in Mal A and B after receiving study vaccine; much higher in Mal B. Infants randomized to bOPV + IPV study vaccine showed incremental immune response against P1 (Mal B, 92.2%; Nor B, 98.4%), P2 (Mal B, 90.4%; Nor B, 94.7%), and P3 (Mal B, 85.6% and Nor B, 93.5%) was observed. A significant proportion of infants in malnourished (P1, 13%; P2, 24%; P3, 26%) and normally nourished group (P1, 5%; P2, 11%; P3, 14%) were found to be seronegative at baseline. Infants who received BOPV + IPV as their study vaccine showed a very high seroconversion response after vaccine (p=<0.001 for P1, P2 and P3). Majority of the specimens were negative at baseline (Mal A, 2%, Mal B, 1%; Nor A, 2%; Nor B, 1%), and remains negative after bOPV challenge dose (Mal A, 8%, Mal B, 6%; Nor A, 11%; Nor B, 10%). Conclusion: Malnourished-infants have low poliovirus-seroprevalence that increased remarkably after IPV. There is less viral shedding after IPV in infants.

Keywords: chronic malnutrition, infants, IPV, OPV

Procedia PDF Downloads 398

Authors: Aghasadeghi MR., Bahramali G., Sadat SM., Sadeghi SA., Yousefi M., Khodaei K., Ghorbani M., Sadat Larijani M.

Abstract:

Background:The emerging COVID-19 pandemic is a serious concernfor the public health worldwide. Despite the many mutations in the virus genome, it is important to find an effective vaccine against viral mutations. Therefore, in current study, we aimed at immunoinformatic evaluation of the virus proteins immunogenicity to design a preventive vaccine candidate, which could elicit humoral and cellular immune responses as well. Methods:Three antigenic regions are included;Spike, Membrane, and Nucleocapsid amino acid sequences were obtained, and possible fusion proteins were assessed andcompared by immunogenicity, structural features, and population coverage. The best fusion protein was also evaluated for MHC-I and MHC-II T-cell epitopes and the linear and conformational B-cell epitopes. Results: Among the four predicted models, the truncated Spike protein in fusion with M and N proteins is composed of 24 highly immunogenic human MHC class I and 29 MHC class II, along with 14 B-cell linear and 61 discontinues epitopes. Also, the selected protein has high antigenicity and acceptable population coverage of 82.95% in Iran and 92.51% in Europe. Conclusion: The data indicate that the truncated Spike-M-N SARS-CoV-2form which could be potential targets of neutralizing antibodies. The protein also has the ability to stimulate humoral and cellular immunity. The in silico study provided the fusion protein as a potential preventive vaccine candidate for further in vivo evaluation.

Keywords: SARS-CoV-2, immunoinformatic, protein, vaccine

Procedia PDF Downloads 223

Authors: Ranjeeta Kumari, Makesh M, Gayatri Tripathi, K V Rajendran, Megha Bedekar

Abstract:

A comparative study on DNA immunization with recombinant glyceraldehyde-3-phosphate dehydrogenase (GAPDH) construct of Edwardsiella tarda (pGPD group) and a bicistronic construct expressing GAPDH plus IFN-γ of Labeo rohita as adjuvant (pGPD+IFN group) was undertaken in Labeo rohita along with the control animals. Successful co-expression of two genes that is GAPDH and IFN-γ was confirmed in SSN-1 cells line by RT-qPCR and western blot. The protective immune response of host to DNA vaccine construct was determined by RPS and specific antibody production. Fishes immunized with plasmids via intramuscular injection (I/M) exhibited a considerable relative percentage survivability of 66.66% in pGPD+IFN immunized group and 53.34% in pGPD immunized group after challenge with E. tarda. Antibody response was also significantly high in pGPD+IFN group at all time points under study. This was analysed by competitive ELISA, using anti GAPDH monoclonal antibodies. The experiment revealed that the GAPDH gene of E. tarda is one of the ideal candidates for generating protective immune response in L. rohita. Further addition of Interferon gamma to DNA vaccine construct can enhance the immune response in host.

Keywords: DNA vaccine, Edwardsiella tarda, Labeo rohita, zoonosis, immune response

Procedia PDF Downloads 203

Authors: Zaw Z Aung

Abstract:

Background: High-risk groups for hepatitis B infection (HBV) are people who injected drugs (PWID), men who have sex with men (MSM), people living with HIV (PLHIV) and persons with hepatitis C (HCV), etc. HBV/HCV coinfected patients are at increased risk of cirrhosis, hepatic decompensation and hepatocellular carcinoma. To the best of author’s knowledge, there is currently no data for hepatitis B vaccine utilization in HCV positive patients and their antibody response. Methodology: From February 2018 to May 2018, consented participants at or above 18 years who came to the clinic in Mandalay were tested with the anti-HCV rapid test. Those who tested HCV positive (n=168) were further tested with hepatitis B profile and asked about their previous hepatitis B vaccination history and risk factors. Results: Out of 168 HCV positive participants, three were excluded for active HBV infections. The remaining 165 were categorized into previously vaccinated 64% (n=106) and unvaccinated 36% (n=59) There were three characteristics groups- PWID monoinfected (n=77), General Population (GP) monoinfected (n=22) and HIV/HCV coinfected participants (n=66). Unvaccinated participants were highest in HIV/HCV, with 68%(n=45) followed by GP (23%, n=5) and PWID (12%, n=9). Among previously vaccinated participants, the highest percentage was PWID (88%, n=68), the second highest was GP (77%, n=17) and lowest in HIV/HCV patients (32%, n=21). 63 participants completed third doses of vaccination (PWID=36, GP=13, HIV/HCV=14). 53% of participants who completed 3 dose of hepatitis B were non-responders (n=34): HIV/HCV (86%, n=12), PWID (44%, n=16), and GP (46%, n=6) Conclusion: Even in the presence of effective and safe hepatitis B vaccine, uptake is low among high risk groups especially PLHIV that needs to be improved. Integration or collaboration of hepatitis B vaccination program, HIV/AIDS and hepatitis C treatment centers is desirable. About half of vaccinated participants were non-responders so that optimal doses, schedule and follow-up testing need to be addressed carefully for those groups.

Keywords: Hepatitis B vaccine, Hepatitis C, HIV, Myanmar

Procedia PDF Downloads 146

Authors: Asavasereerat K., Teacharsripaitoon T., Tungyingyong P., Charupongrat S., Noppiboon S. Hochareon L., Kitsuban P.

Abstract:

Third generation of vaccines is based on gene therapy where DNA is introduced into patients. The antigenic or therapeutic proteins encoded from transgenes DNA triggers an immune-response to counteract various diseases. Moreover, DNA vaccine offers the customization of its ability on protection and treatment with high stability. The production of DNA vaccines become of interest. According to USFDA guidance for industry, the recommended limits for impurities from host cell are lower than 1%, and the active conformation homogeneity supercoiled DNA, is more than 80%. Thus, the purification strategy using two-steps chromatography has been established and verified for its robustness. Herein, pVax1/lacZ, a pre-approved USFDA DNA vaccine backbone, was used and transformed into E. coli strain DH5α. Three purification process parameters including sample-loading flow rate, the salt concentration in washing and eluting buffer, were studied and the experiment was designed using response surface method with central composite face-centered (CCF) as a model. The designed range of selected parameters was 10% variation from the optimized set point as a safety factor. The purity in the percentage of supercoiled conformation obtained from each chromatography step, AIEX and HIC, were analyzed by HPLC. The response data were used to establish regression model and statistically analyzed followed by Monte Carlo simulation using SAS JMP. The results on the purity of the product obtained from AIEX and HIC are between 89.4 to 92.5% and 88.3 to 100.0%, respectively. Monte Carlo simulation showed that the pVAX1/lacZ purification process is robust with confidence intervals of 0.90 in range of 90.18-91.00% and 95.88-100.00%, for AIEX and HIC respectively.

Keywords: AIEX, DNA vaccine, HIC, puification, response surface method, robustness

Procedia PDF Downloads 207

Authors: Chengbin Wang, Li Lu, Luodan Suo, Qinghai Wang, Fan Yang, Xu Wang, Mona Marin

Abstract:

Background: Two-dose varicella vaccination has been recommended in Beijing since November 2012. We investigated a varicella outbreak in a highly vaccinated elementary school population to examine transmission patterns and risk factors for vaccine failure. Methods: A varicella case was defined as an acute generalized maculopapulovesicular rash without other apparent cause in a student attending the school from March 28 to May 17, 2015. Breakthrough varicella was defined as varicella >42 days after last vaccine dose. Vaccination information was collected from immunization records. Information on prior disease and clinical presentation was collected via survey of students’ parents. Results: Of the 1056 school students, 1028 (97.3%) reported no varicella history, of whom 364 (35.4%) had received 1-dose and 650 (63.2%) had received 2-dose varicella vaccine, for 98.6% school-wide vaccination coverage with ≥ 1 dose before the outbreak. A total of 20 cases were identified for an overall attack rate of 1.9%. The index case was in a 2-dose vaccinated student who was not isolated. The majority of cases were breakthrough (19/20, 95%) with attack rates of 7.1% (1/14), 1.6% (6/364) and 2.0% (13/650) among unvaccinated, 1-dose, and 2-dose students, respectively. Most cases had < 50 lesions (18/20, 90%). No difference was found between 1-dose and 2-dose breakthrough cases in disease severity or sociodemographic factors. Conclusion: Moderate 2-dose varicella vaccine coverage was insufficient to prevent a varicella outbreak. Two-dose breakthrough varicella is still contagious. High 2-dose varicella vaccine coverage and timely isolation of ill persons might be needed for varicella outbreak control in the 2-dose era.

Keywords: varicella, outbreak, breakthrough varicella, vaccination

Procedia PDF Downloads 335