scholarly journals Effectiveness of the SA 14-14-2 Live-Attenuated Japanese Encephalitis Vaccine in Myanmar

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 568
Author(s):  
Mya Myat Ngwe Tun ◽  
Aung Kyaw Kyaw ◽  
Khine Mya Nwe ◽  
Shingo Inoue ◽  
Kyaw Zin Thant ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Vaccination Campaign ◽  
Age Groups ◽  
Neutralizing Antibody ◽  
Blood Collection ◽  
Cross Sectional ◽  
Single Time ◽  
Japanese Encephalitis Vaccine

Myanmar is an endemic country for the Japanese encephalitis virus (JEV), and the SA-14-14-2 live-attenuated JEV vaccine was first introduced as a catch-up vaccination campaign in 2017. To determine the effectiveness of vaccination by means of neutralizing antibody titers against JEV, a cross-sectional descriptive study was conducted among five to 15-year-old monastic school children in Mandalay, Myanmar. A total of 198 students who had received vaccines were recruited, and single-time investigation of anti-JEV IgG and neutralizing antibodies against wild-type JEV were determined using anti-JEV IgG ELISA and plaque reduction neutralization tests (PRNT50). All students 100% (198/198) showed positive results on the anti-JEV IgG ELISA, and 87% (172/198) of the students had neutralizing antibodies against JEV six months after immunization. The geometric mean titers of both IgG antibodies and neutralizing antibodies increased with the participants’ age groups, and statistically significant differences in anti-JEV IgG titers were noted across age groups. In this study, we could not investigate the persistence of neutralizing antibodies as only single-time blood collection was done. This study, which is the first report of JEV vaccination among children in Myanmar, showed similar neutralizing antibody production rates among vaccinated individuals as did studies in other countries.

scholarly journals A chimeric Japanese encephalitis vaccine protects against lethal yellow fever virus infection without inducing neutralizing antibodies

2019 ◽  
Author(s):  
Niraj Mishra ◽  
Robbert Boudewijns ◽  
Michael A. Schmid ◽  
Rafael Elias Marques ◽  
Sapna Sharma ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Japanese Encephalitis ◽  
Neutralizing Antibodies ◽  
Yellow Fever Virus ◽  
Neutralizing Antibody ◽  
Fever Virus ◽  
Off Label Use ◽  
Off Label ◽  
Japanese Encephalitis Vaccine ◽  
Label Use

ABSTRACTRecent massive outbreaks of yellow fever virus (YFV) in West Africa and Brazil resulted in rapid depletion of global vaccine emergency stockpiles and raised concerns about being not prepared against future YFV epidemics. Here we report that a live-attenuated virus similar to the Japanese encephalitis virus (JEV) vaccine JE-CVax/Imojev® that consists of YFV-17D vaccine from which the structural (prM/E) genes have been replaced with those of the JEV SA14-14-2 vaccine strain confers full protection in mice against lethal YFV challenge. In contrast to the YFV-17D mediated protection against YFV, this protection is not mediated by neutralizing antibodies but correlates with YFV-specific non-neutralizing antibodies and T cell responses against cell-associated YFV NS1 and other YFV non-structural (NS) proteins. Our findings reveal the importance of YFV NS proteins to mediate protection and demonstrate that chimeric flavivirus vaccines, such as Imojev® can confer protection against two flaviviruses. This dual protection has implications for the possible off-label use of JE-CVax in case of emergency and vaccine shortage during YFV outbreaks. In addition, populations in Asia that have been vaccinated with Imojev® may already be protected against YFV should outbreaks ever occur on that continent as feared by WHO.IMPORTANCEEfficient and safe vaccines exist against yellow fever (e.g. YFV-17D) that provide long-lasting protection by rapidly inducing neutralizing antibody responses. However, vaccine supply cannot cope with an increasing demand posed by massive urban outbreaks in recent years. Here we report that JE-CVax/Imojev®, a YFV-17D-based chimeric Japanese encephalitis vaccine also efficiently protects against YFV infection in mice. In case of shortage of the YFV vaccine during yellow fever outbreaks, (off-label) use of JE-CVax/Imojev® may be considered. Moreover, wider use of JE-CVax/Imojev® in Asia may lower the risk of the much-feared YFV spill over to the continent. More in general chimeric vaccines that combine surface antigens and replication machineries of two distinct flaviviruses can be considered dual vaccines, for the latter pathogen without induction of surface-specific antibodies. Following this rationale, novel flavivirus vaccines that do not hold a risk for antibody-dependent enhancement (ADE) of infection [inherent to current dengue vaccines and dengue vaccine candidates] could be designed.

scholarly journals Seroprevalence of Neutralizing Antibodies against Japanese Encephalitis Virus among Adolescents and Adults in Korea: A Prospective Multicenter Study

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 328
Author(s):  
Byung Ok Kwak ◽  
Young Se Kwon ◽  
Young Jin Hong ◽  
Chung Hyun Nahm ◽  
Woori Jang ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Neutralizing Antibodies ◽  
Age Groups ◽  
Neutralizing Antibody ◽  
Korean Population ◽  
Pseudotyped Virus ◽  
Virus Assay ◽  
Primary Series ◽  
Adolescents And Adults ◽  
Adult Immunization

The immunization schedule for the Japanese encephalitis (JE) vaccine in Korea is a two-dose primary series at 12–24 months of age, followed by booster doses 12 months after the second dose and at the ages of 6 and 12 years. Although the number of JE cases has markedly decreased after the universal vaccination program, JE predominantly occurs in adults. The aim of this study was to assess the age-specific prevalence of the JE-neutralizing antibody (NTAb) among adolescents and adults in Korea. A total of 1603 specimens were collected from a healthy Korean population above 15 years old in five provinces. The JE-NTAb titers were measured with the pseudotyped virus assay and considered to be positive at ≥ 1:50. The seropositivity of JE-NTAb was the highest in the 15–29 years category (>95%) and gradually began to decrease in the age group of 30–44 years (89.42%). The lowest and second lowest JE-NTAb seropositive rates were observed among those aged 70 years or older (59.77%) and those aged 55–59 years (75.24%), respectively. Subjects from Seoul exhibited the highest JE-NTAb titer in all age groups compared to other provinces. In conclusion, the JE-NTAb seropositive rates and titers have maintained appropriate levels in the general Korean population. We propose that adult immunization and boosters at 12 years of age against JE are not strongly recommended in Korea.

scholarly journals Communication and awareness on a new vaccine: a cross-sectional study in a tertiary care hospital of West Bengal

2019 ◽  
Vol 7 (1) ◽  
pp. 345
Author(s):  
Arup Chakraborty ◽  
Mousumi Datta ◽  
Debjani Guchhait ◽  
Shibaji Gupta
Keyword(s):  
Japanese Encephalitis ◽  
Disease Transmission ◽  
Vaccination Campaign ◽  
Tertiary Care ◽  
Age Groups ◽  
Uttar Pradesh ◽  
Cross Sectional Study ◽  
Care Hospital ◽  
Cross Sectional ◽  
Care Givers

Background: Japanese encephalitis (JE) vaccination in India started in 2006 with SA-14-14-2 live attenuated JE vaccine (JEV) following large outbreaks of JE in some districts of Eastern Uttar Pradesh and Bihar in 2005. Age groups 1-15 yrs are first vaccinated with a single dose of JEV in a campaign mode followed by integration of this vaccine in routine immunization. It is beyond doubt that added to vaccination campaigns, proper awareness on JE can play significant role in controlling the disease.Methods: An observational study with cross sectional design was conducted in Kolkata Medical College and Hospital, Kolkata during JE Vaccination campaign during January, 2018 among 85 respondents, to assess the awareness on JE, among care-givers who brought their children for vaccination at the immunization clinic.Results: It was found that only 37.6% the respondents attending the campaign knew the name of the disease; 17.6% respondents were aware about disease transmission, and 5.9% could state two or more clinical features that might be associated with Japanese Encephalitis. 69.4% had no knowledge of up to what age JE vaccines can be administered; 23.5% said it can be administered till the beneficiaries attain fifteen years of age.Conclusions: IEC activities during JE vaccination campaign was not able raise awareness on JE to the desired level. However beneficiaries were informed about service availability and could be mobilised to come for vaccination.

scholarly journals First seroepidemiological investigation of human enterovirus 71 in Iran

2021 ◽  
Author(s):  
Mahsa Javadi ◽  
Ahmad Nejati ◽  
Maryam Yousefi ◽  
Mahmood Mahmoodi ◽  
Zabihollah Shoja ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neurological Diseases ◽  
Age Groups ◽  
Enterovirus 71 ◽  
Neutralizing Antibody ◽  
Human Enterovirus ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Cross Sectional ◽  
Human Enterovirus 71

Background and Objectives: Human Enterovirus 71 (EV-A71) is the causative agent for many dermal to neurological diseases especially polio-like paralysis outbreaks around the world. This study, the first of this kind in Iran, aimed to find neu- tralizing antibodies against EV-A71 in serum of healthy individuals in different age groups based on neutralization test (NT). Materials and Methods: In this cross-sectional study, 547 serum samples were collected from healthy individuals who were referring for routine checkup tests (aged from under 6 months to over 31 years old) to Imam-Khomeini Hospital in Tehran during January-December 2015. Serum samples were examined by NT in cell culture to detect neutralizing antibodies against EV-A71. In the next step, some of the positive samples were subjected to complete titration to determine the exact titer of anti-EV-A71 antibodies. Results: Of 547 samples, 310 (56.7%) were positive for EV-A71 neutralizing antibody. The presence of the antibody in- creased with age (p<0.001), and there was a significant statistical relationship between sex and the presence of antibody (p=0.009). Conclusion: Our results demonstrated an apparent but limited circulation of EV-A71 in our society. After the worldwide eradication of poliovirus, EV-A71 which can cause polio-likes syndrome, might be the new challenge for our health care system as regard more in depth research is however needed.

scholarly journals Retention of neutralizing antibodies to Japanese encephalitis vaccine in age groups above fifteen years in Korea

2020 ◽  
Vol 100 ◽  
pp. 53-58
Author(s):  
Hee-Jung Lee ◽  
Hanul Choi ◽  
Ki Hoon Park ◽  
Yuyeon Jang ◽  
Young-jin Hong ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Neutralizing Antibodies ◽  
Age Groups ◽  
Japanese Encephalitis Vaccine

scholarly journals Long Term Follow up of the Lived Attenuated Japanese Encephalitis Vaccine (SA-14-14-2) Efficacy in Children of the four hyper-endemic Provinces of Northern Thailand, 2016.

2020 ◽  
Author(s):  
Narong Nitatpattana ◽  
Khajornpong Nakgoi ◽  
Sanjira Juntarapornchai ◽  
Sasiporn Ruangdachsuwan ◽  
Supot Ratchakum ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Neutralizing Antibodies ◽  
Seroconversion Rate ◽  
Neutralizing Antibody ◽  
Northern Region ◽  
Japanese Encephalitis Vaccine ◽  
Long Term Follow Up ◽  
One Year

Abstract Background. In Thailand, Japanese encephalitis appears with a higher incidence of the Northern region (0.0/100,000 cases/year) as compared to the central southern region of the country (0.01/100,000/year). Also, all Japanese encephalitis virus (JEV) recently isolated strains in country belong to the genotype I and III.Methods. In order to evaluate the long-term efficacy of the newly developed live attenuated SA 14-14-2 Japanese encephalitis vaccine in Thailand, the immune response in children was studied after a second immunization campaign. Following 2012 immunization campaign, a second JEV immunization vaccine was delivered to children among four provinces of the Northern Region of Thailand. For each province, the recipients were identified accordingly to the two vaccine campaigns time including the children who received the second dose of vaccine: 1/ less than one year before the present study (N=30 by province); 2/ more than one year before the present study (N=70 by province). Altogether, a total of 400 children were enrolled in this project. After receiving the second vaccine dose, blood samples were collected and tested for JEV (Genotypes I and III) neutralizing antibodies following a standard procedure of LLC-MK2 infected cells.Results. All recipient presented neutralizing antibodies cross reacting against the prevalent JEV genotypes I (SM1 JEV strain) and genotype III (SA 14-14-2 and Beijing JEV strains). Most of the children from the first group had a seroconversion rate of 94.2% against homologous (i.e. GIII). Among them, an optimal rate of 100% seroconversion was find at the Phayao Province against both heterologous (GI) and homologous (GIII) JEV strains. Geometric Mean Titer (GMT) of neutralizing antibody against SM1, SA 14-14-2 JEV, and Beijing JEV strains were consistently high, respectively as 239±50, 323±201.2 and 177±36.7. For the second group, seroconversion rate was lower against SM1, SA 14-14-2 and Beijing JEV strains with a rate of 94.3, 90% and 86.8% with respectively a GMT of 154±32, 90±23 and 82±13.6.Conclusion. Although, the immunity appears to decrease within the period of 2.5 years, neutralizing antibody rate are consistent to protect against the JEV infection. Nevertheless, a long-term follow up is suitable to evaluate an eventual third dose opportunity.

scholarly journals Serological Study of Neutralizing Antibodies Against Enterovirus D68 Among Healthy Population in Xiamen, China

2020 ◽  
Author(s):  
Tong Cheng ◽  
Yu Lin ◽  
Rui Zhu ◽  
Yuanyuan Wu ◽  
Longfa Xu ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Age Groups ◽  
Neutralizing Antibody ◽  
Respiratory Illness ◽  
Risk Groups ◽  
Healthy Population ◽  
Serum Samples ◽  
Xiamen City ◽  
Enterovirus D68

Abstract Background: Enterovirus D68 (EV-D68) infections poses a serious public health threat, which caused outbreaks of severe respiratory illness and has been closely associated with "polio-like" central nervous system disease. The patterns of immune responses to EV-D68 have not been fully understood. This study was performed to investigate the level of neutralizing antibody against EV-D68 among the healthy population in Xiamen City.Methods: A total of 515 serum samples from healthy people were selected by stratified random sampling in Xiamen City in 2016, and the titer of neutralizing antibody against EV-D68 was detected by an efficient micro-neutralization assay.Results: The overall seroprevalence of neutralizing antibody against EV-D68 was 81.9%, and the overall geometric mean titers (GMT) was 248.0. The positive rates were 42.2%, 49.3%, 71.9%, 94.2% and 98.5%, respectively, in groups of <1, 1-3, 4-6, 7-19 and 20-39 years old, and were up to 100% in the 40-59 and ≥ 60 age groups. The GMTs in these seven groups were 1:39.8, 1:80.6, 1:133.2, 1:283.7, 1:253.3, 1:308.1 and 1:405.0, respectively. The seroprevalence and GMT of EV-D68 showed an increased trend with age, while gender and geographic area didn’t show significant impact.Conclusions: EV-D68 infection was prevalent in Xiamen City. Children are the high-risk groups for EV-D68-related illnesses, especially those aged ≤ 3 years. It is necessary to establish preventive measures and strengthened the surveillance on EV-D68 to prevent disease outbreaks.

scholarly journals Duration of immunity against COVID-19 after vaccination in Indian subcontinent

2022 ◽  
Author(s):  
Apoorva Munigela ◽  
Sasikala M ◽  
Gujjarlapudi Deepika ◽  
Anand V Kulkarni ◽  
Krishna Vemula ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Booster Dose ◽  
Indian Subcontinent ◽  
Neutralizing Antibody ◽  
Health Concern ◽  
Mortality Data ◽  
Optimal Timing ◽  
Cross Sectional ◽  
Mortality And Morbidity ◽  
Antibody Levels

Abstract Coronavirus disease (COVID-19) continues to be a major health concern leading to substantial mortality and morbidity across the world. Vaccination is effective in reducing the severity and associated mortality. Data pertaining to the duration of immunity, antibody waning and the optimal timing of booster dose administration is limited. In this cross-sectional study, we assessed the antibody levels in healthcare workers who were fully vaccinated after obtaining Institutional ethics committee approval and informed consent. Whole blood was collected and enumeration of S1/S2 neutralizing antibody levels was carried out using LIAISON SARS-COV-2 S1/S2 IgG assay. A total of 1636 individuals who were vaccinated with Covaxin or Covishield were included. Of these, 52% were males with a median age of 29 years. Diabetes and Hypertension was noted in 2.32% (38/1636) and 2.87% (47/1636) of the individuals. Spike neutralizing antibodies were below the detectable range (<15 AU/ml) in 6.0% (98/1636) of the individuals. Decline in neutralizing antibody was seen in 30% of the individuals above 40 years of age with comorbidities (diabetes and hypertension) after 6 months. These individuals may be prioritized for a booster dose at 6 months.

scholarly journals Antibody titers measured by commercial assays are correlated with neutralizing antibody titers calibrated by international standards

2021 ◽  
Author(s):  
Yu-An Kung ◽  
Chung-Guei Huang ◽  
Sheng-Yu Huang ◽  
Kuan-Ting Liu ◽  
Peng-Nien Huang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Diagnostic Techniques ◽  
International Standards ◽  
World Health ◽  
Serum Samples ◽  
Antibody Titers ◽  
Health Organization

The World Health Organization (WHO) has highlighted the importance of an international standard (IS) for SARS-CoV-2 neutralizing antibody titer detection, with the aim of calibrating different diagnostic techniques. In this study, IS was applied to calibrate neutralizing antibody titers (IU/mL) and binding antibody titers (BAU/mL) in response to SARS-CoV-2 vaccines. Serum samples were collected from participants receiving the Moderna (n = 20) and Pfizer (n = 20) vaccines at three time points: pre-vaccination, after one dose, and after two doses. We obtained geometric mean titers of 1404.16 and 928.75 IU/mL for neutralizing antibodies after two doses of the Moderna and Pfizer vaccines, respectively. These values provide an important baseline for vaccine development and the implementation of non-inferiority trials. We also compared three commercially available kits from Roche, Abbott, and MeDiPro for the detection of COVID-19 antibodies based on binding affinity to S1 and/or RBD. Our results demonstrated that antibody titers measured by commercial assays are highly correlated with neutralizing antibody titers calibrated by IS.

scholarly journals Seroprevalence of anti-SARS-CoV-2 antibodies six months into the vaccination campaign in Geneva, Switzerland

2021 ◽  
Author(s):  
Silvia Stringhini ◽  
María-Eugenia Zaballa ◽  
Nick Pullen ◽  
Javier Perez-Saez ◽  
Carlos de Mestral ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Age Groups ◽  
Credible Interval ◽  
Population Based ◽  
Vaccine Hesitancy ◽  
Socioeconomically Disadvantaged ◽  
Cross Sectional ◽  
Vaccination Rates ◽  
Health Measures ◽  
Random Samples

Background: Up-to-date seroprevalence estimates are critical to describe the SARS-CoV-2 immune landscape in the population and guide public health measures. We aimed to estimate the seroprevalence of anti-SARS-CoV-2 antibodies 15 months into the COVID-19 pandemic and six months into the vaccination campaign. Methods: We conducted a population-based cross-sectional serosurvey between June 1 and July 7, 2021, recruiting participants from age- and sex-stratified random samples of the general population. We tested participants for anti-SARS-CoV-2 antibodies targeting the spike (S) or nucleocapsid (N) proteins (Roche Elecsys immunoassays). We estimated the anti-SARS-CoV-2 antibodies seroprevalence following vaccination and/or infection (anti-S antibodies), or infection only (anti-N antibodies). Results: We included 3355 individuals, of which 1814 (54.1%) were women, 697 (20.8%) were aged <18 years and 449 (13.4%) were aged ≥65 years, 2161 (64.4%) tested positive for anti-S antibodies, and 906 (27.0%) tested positive for anti-N antibodies. The total seroprevalence of anti-SARS-CoV-2 antibodies was 66.1% (95% credible interval, 64.1-68.0). Considering the presence of anti-N antibodies, we estimated that 29.9% (28.0-31.9) of the population developed antibodies after infection; the rest having developed antibodies only via vaccination. Seroprevalence estimates were similar across sexes, but differed markedly across age groups, being lowest among children aged 0-5 years (20.8% [15.5-26.7]) and highest among older adults aged ≥75 years (93.1% [89.6-96.0]). Seroprevalence of antibodies developed via infection and/or vaccination was higher among participants with a higher educational level. Conclusions: Most adults have developed anti-SARS-CoV-2 antibodies, while most teenagers and children remain vulnerable to infection. As the SARS-CoV-2 Delta variant spreads and vaccination rates stagnate, efforts are needed to address vaccine hesitancy, particularly among younger individuals and socioeconomically disadvantaged groups, and to minimize spread among children.

Sign in / Sign up

Export Citation Format

Share Document