The incidence of Japanese encephalitis(JE)has significantly decreased in China due to JE vaccines.In this study,we investigated the post-JE vaccination seroprevalence and protection provided by vaccinated sera against...The incidence of Japanese encephalitis(JE)has significantly decreased in China due to JE vaccines.In this study,we investigated the post-JE vaccination seroprevalence and protection provided by vaccinated sera against Japanese encephalitis virus(JEV)to elucidate the persistence and waning of antibodies to JEV among JE-SA14-14-2-vaccinated children.A total of 300 serum samples were collected from vaccinated children aged 3-10 years in Zhaotong,Yunnan,China.The seroprevalence of anti-JEV antibodies was determined by enzyme-linked immune sorbent assay and plaque reduction neutralization test.The highest seropositivity of 82%was observed in vaccinated children during the first 0.5-1.5 years after booster vaccination.Then,the seropositivity began to decline and remained lower than the original level observed in the 0.5-1.5-year group.An association was found between the waning of seroprevalence and elapsed time of the post-booster vaccination.Similarly,the neutralizing antibody(nAb)titres gradually decreased over time,and the levels showed a positive correlation with the protective efficacy in mice.This finding suggests that nAbs play an important role in the antiviral process and that the nAb titre is an adequately credible parameter for evaluating the protective efficacy induced by the JE vaccine.Our results provide data that clarify the persistence and waning of antibodies to JEV,which may help elucidate the pathogenesis of JE.展开更多
Dear Editor,Chikungunya virus(CHIKV),an arbovirus in the family of Togaviridae,genus Alphavirus,is transmitted by the A.aegyptii or A.albopictus mosquito,and causes disease in humans characterized by fever,rash,and ar...Dear Editor,Chikungunya virus(CHIKV),an arbovirus in the family of Togaviridae,genus Alphavirus,is transmitted by the A.aegyptii or A.albopictus mosquito,and causes disease in humans characterized by fever,rash,and arthralgia(Silva and Dermody 2017;Suhrbier 2019).It was first reported in 1953 in Tanzania,and caused only a few outbreaks and sporadic cases in Africa and Asia in last century.However,in the epidemic in 2004,CHIKV acquired mutations that conferred enhanced transmission by the A.albopictus mosquito(Schuffenecker et al.2006).Since then,it has successively caused outbreaks in Africa,the Indian Ocean,South East Asia,the South America,and Europe(Zeller et al.2016).展开更多
After dengue virus(DENV)infection,antibody-dependent enhancement(ADE)is easy to occur when the neutralizing antibody(NAb)gradually decreases to a sub-neutralizing concentration.In this cohort surveillance,we utilized ...After dengue virus(DENV)infection,antibody-dependent enhancement(ADE)is easy to occur when the neutralizing antibody(NAb)gradually decreases to a sub-neutralizing concentration.In this cohort surveillance,we utilized sera samples collected from dengue fever patients at different convalescent phases in Jinghong City,to investigate the dynamic change rule of DENV-specific antibodies,and to analyze the risk of ADE caused by secondary infection with heterologous serotypes DENVs.For baseline serosurvey,191 four-year and 99 six-year sera samples during convalescence were collected in 2017 and 2019,respectively.The positive rate of DENVspecific immunoglobulin G was 98.4%in 2017,which significantly decreased to 82.8%in 2019.The geometric mean titer(GMT)of NAb decreased from 1:155.35 to 1:46.66.Among 290 overall samples,73 paired consecutive samples were used for follow-up serosurvey.In four-year sera,the GMTs of NAb against DENV-3 and cross-reactive antibodies against DENV-1,DENV-2 and DENV-4 were 1:167.70,1:13.80,1:18.54 and 1:45.26,respectively,which decreased to 1:53.18,1:10.30,1:14.60 and 1:8.17 in six-year sera.In age-stratified analysis,due to the increasing number of ADE positive samples from 2017 to 2019 in 31–40 and 51–60 years groups,the risk of ADE in DENV-4 infection was positively associated with the extension of convalescent phase,and the odd ratio was higher than other groups.With the recovery period lengthened,the risk of secondary infection with DENV-1 and DENV-2 was reduced.Our results offer essential experimental data for risk prediction of severe dengue in hyper-endemic dengue areas,and provide crucial scientific insight for the development of effective dengue vaccines.展开更多
基金supported by grants from the National Natural Science Foundation of China (81471957, 81772172, 81671971, U1602223 and 81871641)a grant from the Open Research Projects of Key Laboratory of Beijing Ditan Hospital, Capital Medical University (DTKF201705)
文摘The incidence of Japanese encephalitis(JE)has significantly decreased in China due to JE vaccines.In this study,we investigated the post-JE vaccination seroprevalence and protection provided by vaccinated sera against Japanese encephalitis virus(JEV)to elucidate the persistence and waning of antibodies to JEV among JE-SA14-14-2-vaccinated children.A total of 300 serum samples were collected from vaccinated children aged 3-10 years in Zhaotong,Yunnan,China.The seroprevalence of anti-JEV antibodies was determined by enzyme-linked immune sorbent assay and plaque reduction neutralization test.The highest seropositivity of 82%was observed in vaccinated children during the first 0.5-1.5 years after booster vaccination.Then,the seropositivity began to decline and remained lower than the original level observed in the 0.5-1.5-year group.An association was found between the waning of seroprevalence and elapsed time of the post-booster vaccination.Similarly,the neutralizing antibody(nAb)titres gradually decreased over time,and the levels showed a positive correlation with the protective efficacy in mice.This finding suggests that nAbs play an important role in the antiviral process and that the nAb titre is an adequately credible parameter for evaluating the protective efficacy induced by the JE vaccine.Our results provide data that clarify the persistence and waning of antibodies to JEV,which may help elucidate the pathogenesis of JE.
基金supported by the National Natural Science Foundation of China under grants U1602223,81671971,81972979,81772172,and 81871641the Scientific Research Plan of the Beijing Municipal Education Committee under grant KM201710025002+2 种基金the Key Project of Beijing Natural Science Foundation B under grant KZ201810025035the Yunnan Institute of Parasitic Diseases Innovative Team of Key Techniques for Vector Borne Disease Control and Prevention(Developing)under grant 2019HC010the Academician Workstation of Professor Jin Ningyi&Training Base of International Scientific Exchange and Education in Tropical Diseases for South and Southeast Asia under grant 2018IC151
文摘Dear Editor,Chikungunya virus(CHIKV),an arbovirus in the family of Togaviridae,genus Alphavirus,is transmitted by the A.aegyptii or A.albopictus mosquito,and causes disease in humans characterized by fever,rash,and arthralgia(Silva and Dermody 2017;Suhrbier 2019).It was first reported in 1953 in Tanzania,and caused only a few outbreaks and sporadic cases in Africa and Asia in last century.However,in the epidemic in 2004,CHIKV acquired mutations that conferred enhanced transmission by the A.albopictus mosquito(Schuffenecker et al.2006).Since then,it has successively caused outbreaks in Africa,the Indian Ocean,South East Asia,the South America,and Europe(Zeller et al.2016).
基金supported by the National Natural Science Foundation of China under grants 81772172,U1902210,81972979 and 81902048
文摘After dengue virus(DENV)infection,antibody-dependent enhancement(ADE)is easy to occur when the neutralizing antibody(NAb)gradually decreases to a sub-neutralizing concentration.In this cohort surveillance,we utilized sera samples collected from dengue fever patients at different convalescent phases in Jinghong City,to investigate the dynamic change rule of DENV-specific antibodies,and to analyze the risk of ADE caused by secondary infection with heterologous serotypes DENVs.For baseline serosurvey,191 four-year and 99 six-year sera samples during convalescence were collected in 2017 and 2019,respectively.The positive rate of DENVspecific immunoglobulin G was 98.4%in 2017,which significantly decreased to 82.8%in 2019.The geometric mean titer(GMT)of NAb decreased from 1:155.35 to 1:46.66.Among 290 overall samples,73 paired consecutive samples were used for follow-up serosurvey.In four-year sera,the GMTs of NAb against DENV-3 and cross-reactive antibodies against DENV-1,DENV-2 and DENV-4 were 1:167.70,1:13.80,1:18.54 and 1:45.26,respectively,which decreased to 1:53.18,1:10.30,1:14.60 and 1:8.17 in six-year sera.In age-stratified analysis,due to the increasing number of ADE positive samples from 2017 to 2019 in 31–40 and 51–60 years groups,the risk of ADE in DENV-4 infection was positively associated with the extension of convalescent phase,and the odd ratio was higher than other groups.With the recovery period lengthened,the risk of secondary infection with DENV-1 and DENV-2 was reduced.Our results offer essential experimental data for risk prediction of severe dengue in hyper-endemic dengue areas,and provide crucial scientific insight for the development of effective dengue vaccines.