Antibody induced by one-dose varicella vaccine soon became weak in children: evidence from a cross-sectional seroepidemiological survey in Beijing, PRC.

Luodan Suo,Meng Chen,Li Lu,Xinghuo Pang

doi:10.1186/s12879-015-1236-x

Luodan Suo, Meng Chen + Show 2 more

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https://doi.org/10.1186/s12879-015-1236-x

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Abstract

BackgroundNumerous post-licensure studies, mostly from field epidemiological evidences such as outbreak surveys, have demonstrated the effectivenesss and insufficiency of one-dose varicella vaccine in outbreak control. Serological evidence of immunization failure is, however, relatively less reported in contrast. A cross-sectional seroepidemiological survey of Beijing residents was performed in 2012 in the People’s Republic of China, after the one-dose varicella vaccine had been widely used for several years.MethodsMultistage stratified random sampling method was designed to recruit 2 144 subjects. The ELISA method was used to test the present blood samples collected and the reserve samples collected in 2008 to assess the trends of anti-VZV seroprevalence in the past 5 years and to determine the risk factors for varicella infection.ResultsThe age- and sex- adjusted overall anti-VZV seropositivity of Beijing residents in 2012 was 84.5 %. Two groups’ adjusted overall anti-VZV seroprevalence in 2012 showed obvious growth compared with 2008 (<1 yr old: from 6.3 % to 16.9 %; 1-4 yr old: from 27.6 % to 57.2 %). Reported one-dose vaccination history was 71.6 % (149/208), 80.9 % (182/225) and 82.2 % (180/219) in the 1-4 yr, 5-9 yr, 10-14 yr age groups, respectively. Of subjects who had received the one-dose vaccine, 36 % (216/603) showed negative anti-VZV concentrations (<110 mIU/mL); additionally 15.9 % (96/603) of such subjects’ anti-VZV concentrations were in the lowest positive concentration group (110-299 mIU/mL). Seropositivity in permanent residents of 1-9 yr old with verified vaccination was merely 61.8 %. Various age groups (1-3 yr, 4-6 yr, and 7-9 yr) all showed seropositivity that gradually decreased with increasing of the interval between vaccination and blood sampling.ConclusionMass varicella vaccination significantly improved the immunity of younger Beijing residents. However, vaccine-induced anti-VZV antibody soon became weak in children with high coverage (approximately 80 %) after vaccination for several years which is significantly higher than reported in pre-licensure studies. A government-funded 2-dose immunization program with mandatory vaccination schedule for Beijing residents may need consideration in the near future.

Highlights

Numerous post-licensure studies, mostly from field epidemiological evidences such as outbreak surveys, have demonstrated the effectivenesss and insufficiency of one-dose varicella vaccine in outbreak control
Varicella is a highly contagious disease caused by infection with the primary varicella zoster virus (VZV)
Varicella vaccines are available globally, some countries have introduced them into the routine immunization program for children, which has succeeded in reducing the morbidity and mortality [2,3,4]

Summary

Introduction

Numerous post-licensure studies, mostly from field epidemiological evidences such as outbreak surveys, have demonstrated the effectivenesss and insufficiency of one-dose varicella vaccine in outbreak control. Before implementation of the varicella vaccination program in 1995, there were approximately four million varicella cases per year [1] in the United States. Numerous post-licensure studies, mostly from field outbreak surveys, have showed the field efficacy and insufficiency of one-dose varicella vaccine in outbreaks control [5]. Based on data obtained from the above-mentioned surveillance and field survey evidence, several countries such as the United States have begun to recommend a second dose of varicella vaccine. The post-licensure serological evidences after mass immunization are relatively much less reported [6]

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