Immunity and clinical efficacy of an inactivated enterovirus 71 vaccine in healthy Chinese children: a report of further observations

Longding Liu, Zhaojun Mo, Zhenglun Liang, Ying Zhang, Rongcheng Li, Kien Chai Ong, Kum Thong Wong, Erxia Yang, Yanchun Che, Jingjing Wang, Chenghong Dong, Min Feng, Jing Pu, Lichun Wang, Yun Liao, Li Jiang, Soon Hao Tan, Perera David, Teng Huang, Zhenxin Zhou, Xuanyi Wang, Jielai Xia, Lei Guo, Ling Wang, Zhongping Xie, Wei Cui, Qunying Mao, Yan Liang, Hongling Zhao, Ruixiong Na, Pingfang Cui, Haijing Shi, Junzhi Wang, Qihan Li, Longding Liu, Zhaojun Mo, Zhenglun Liang, Ying Zhang, Rongcheng Li, Kien Chai Ong, Kum Thong Wong, Erxia Yang, Yanchun Che, Jingjing Wang, Chenghong Dong, Min Feng, Jing Pu, Lichun Wang, Yun Liao, Li Jiang, Soon Hao Tan, Perera David, Teng Huang, Zhenxin Zhou, Xuanyi Wang, Jielai Xia, Lei Guo, Ling Wang, Zhongping Xie, Wei Cui, Qunying Mao, Yan Liang, Hongling Zhao, Ruixiong Na, Pingfang Cui, Haijing Shi, Junzhi Wang, Qihan Li

Abstract

Background: To investigate the long-term effects on immunity of an inactivated enterovirus 71 (EV71) vaccine and its protective efficacy.

Methods: A sub-cohort of 1,100 volunteers from Guangxi Province in China was eligible for enrolment and randomly administered either the EV71 vaccine or a placebo on days 0 and 28 in a phase III clinical trial and then observed for the following 2 years with approval by an independent ethics committee of Guangxi Zhuang Autonomous Region, China. Serum samples from the 350 participants who provided a full series of blood samples (at all the sampling points) within the 2-year period were collected. Vaccine-induced immune effects, including the neutralizing antibody titres and cross-protection against different genotypes of EV71, were examined. This study also evaluated the protective efficacy of this vaccine based upon clinical diagnosis.

Results: This sub-cohort showed a >60% drop-out rate over 2 years. The seroconversion rates among the 161 immunized subjects remained >95% at the end of study. The geometric mean titres of neutralizing antibodies (anti-genotype C4) 360 days after vaccination in 350 subjects were 81.0 (subjects aged 6-11 months), 98.4 (12-23 months), 95.0 (24-35 months), and 81.8 (36-71 months). These titres subsequently increased to 423.1, 659.0, 545.0, and 321.9, respectively, at 540 days post-immunization (d.p.i.), and similar levels were maintained at 720 d.p.i. Higher IFN-γ/IL-4-specific responses to the C4 genotype of EV71 and cross-neutralization reactivity against major EV71 genotype strains were observed in the vaccine group compared to those in the placebo group. Five EV71-infected subjects were observed in the placebo-treated control group and none in the vaccine-immunized group in per-protocol analysis.

Conclusion: These results are consistent with the induction of dynamic immune responses and protective efficacy of the vaccine against most circulating EV71 strains.

Trial registration number: Clinicaltrials.gov, NCT01569581, Trial registration date: March 2012.

Figures

Fig. 1
Fig. 1
Schematic representation of the phase III clinical trial of an inactivated enterovirus 71 vaccine. In total, 14,445 children, aged 6–71 months, were assessed for a phase III clinical trial and 12,000 eligible volunteers were randomly assigned to receive the vaccine or a placebo [8]. The blood samples of 1,100 individuals were collected at 0, 56, 180, 360, 540, and 720 days after immunization to evaluate the production of anti-EV71 neutralizing antibodies. The follow-up rates (%) are indicated for each time point
Fig. 2
Fig. 2
Dynamic profiles of the antibody levels during a 2-year follow-up period in 350 children immunized with the vaccine. Blood samples from 350 participants, who provide a full series of blood samples within the 2-year follow-up period, were collected to evaluate the production of anti-EV71 neutralizing antibodies. These children were 6–11 months old (a) (48 individuals in the vaccine group and 50 in the placebo group), 12–23 months old (b) (50 individuals in the vaccine group and 63 in the placebo group), 24–35 months old (c) (43 individuals in the vaccine group and 52 in the placebo group), and 36–71 months old (d) (20 individuals in the vaccine group and 24 in the placebo group). The geometric mean titres are shown above the bar. The bar indicates the 95 % confidence interval
Fig. 3
Fig. 3
EV71 antigen stimulated specific IFN-γ and IL-4 responses in peripheral blood mononuclear cells from volunteers immunized with either the vaccine or placebo. Blood samples from 40 participants from among the 350 subjects who provided a full series of blood samples within the 2-year follow-up period were obtained at 720 days after immunization to evaluate IFN-γ and IL-4 production. These children were 6–11 months old (a) (five individuals in the vaccine group and five in the placebo group), 12–23 months old (b) (five individuals in the vaccine group and five in the placebo group), 24–35 months old (c) (five individuals in the vaccine group and five in the placebo group), and 36–71 months old (d) (five individuals in the vaccine group and five in the placebo group). The mean levels of cytokines are shown above the bar
Fig. 4
Fig. 4
Cumulative cases of hand, foot, and mouth disease (HFMD) reported in 350 participants. A total of 350 participants (161 individuals in the vaccine group and 189 in the placebo group), who provided a full series of blood samples (at all the sampling points) within the 2-year study period, were observed during the surveillance period. The cumulative curves for the cases of HFMD induced by enterovirus 71 (EV71), coxsackievirus A16 (CA16), and other enteroviruses were estimated as a percentage among these participants with Kaplan–Meier survival curves during the period from the receipt of the first dose until 24 months thereafter. The inset shows the same data on an enlarged y-axis. Differences in the distributions of cases of HFMD among the individuals who received the placebo and those who received the vaccine were evaluated with a log-rank test. a Cumulative curve for the cases of HFMD induced by EV71. b Cumulative curve for the cases of HFMD induced by CA16. c Cumulative curve for the cases of HFMD induced by other enteroviruses
Fig. 5
Fig. 5
Cross-neutralizing reactivity of different viral strains of various genotypes to sera taken from 160 individuals. Serum samples from 160 individuals (40 individuals in each age group; 20 individuals in the vaccine group and 20 in the placebo group), from among the 350 subjects who provided a full series of blood samples within the 2-year study period, were collected at 0, 56, and 360 days post-immunization for a cross-neutralization assay with different genotypes of enterovirus 71: A, B (B3–B5), and C (C1–C5). The geometric mean titres are shown above the bar. The bar indicates the 95 % confidence interval

References

    1. Ho M, Chen ER, Hsu KH, Twu SJ, Chen KT, Tsai SF, et al. An epidemic of enterovirus 71 infection in Taiwan. Taiwan Enterovirus Epidemic Working Group. N Engl J Med. 1999;341:929–35. doi: 10.1056/NEJM199909233411301.
    1. Tan X, Huang X, Zhu S, Chen H, Yu Q, Wang H, et al. The persistent circulation of enterovirus 71 in People’s Republic of China: causing emerging nationwide epidemics since 2008. PLoS One. 2011;6:e25662. doi: 10.1371/journal.pone.0025662.
    1. McMinn PC. An overview of the evolution of enterovirus 71 and its clinical and public health significance. FEMS Microbiol Rev. 2002;26:91–107. doi: 10.1111/j.1574-6976.2002.tb00601.x.
    1. Ma E, Chan KC, Cheng P, Wong C, Chuang SK. The enterovirus 71 epidemic in 2008--public health implications for Hong Kong. Int J Infect Dis. 2010;14:e775–80. doi: 10.1016/j.ijid.2010.02.2265.
    1. Ang LW, Koh BK, Chan KP, Chua LT, James L, Goh KT. Epidemiology and control of hand, foot and mouth disease in Singapore, 2001–2007. Ann Acad Med Singapore. 2009;38:106–12.
    1. Xu W, Liu CF, Yan L, Li JJ, Wang LJ, Qi Y, et al. Distribution of enteroviruses in hospitalized children with hand, foot and mouth disease and relationship between pathogens and nervous system complications. Virol J. 2012;9:8. doi: 10.1186/1743-422X-9-8.
    1. Wang Y, Feng Z, Yang Y, Self S, Gao Y, Longini IM, et al. Hand, foot, and mouth disease in China: patterns of spread and transmissibility. Epidemiology. 2011;22:781–92. doi: 10.1097/EDE.0b013e318231d67a.
    1. Li R, Liu L, Mo Z, Wang X, Xia J, Liang Z, et al. An inactivated enterovirus 71 vaccine in healthy children. N Engl J Med. 2014;370:829–37. doi: 10.1056/NEJMoa1303224.
    1. Zhu F, Xu W, Xia J, Liang Z, Liu Y, Zhang X, et al. Efficacy, safety, and immunogenicity of an enterovirus 71 vaccine in China. N Engl J Med. 2014;370:818–28. doi: 10.1056/NEJMoa1304923.
    1. Zhu FC, Meng FY, Li JX, Li XL, Mao QY, Tao H, et al. Efficacy, safety, and immunology of an inactivated alum-adjuvant enterovirus 71 vaccine in children in China: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2013;381:2024–32. doi: 10.1016/S0140-6736(13)61049-1.
    1. Ma H, He F, Wan J, Jin D, Zhu L, Liu X, et al. Glucocorticoid and pyrazolone treatment of acute fever is a risk factor for critical and life-threatening human enterovirus 71 infection during an outbreak in China, 2008. Pediatr Infect Dis J. 2010;29:524–9.
    1. Shimizu H, Utama A, Onnimala N, Li C, Li-Bi Z, Yu-Jie M, et al. Molecular epidemiology of enterovirus 71 infection in the Western Pacific Region. Pediatr Int. 2004;46:231–5. doi: 10.1046/j.1442-200x.2004.01868.x.
    1. Solomon T, Lewthwaite P, Perera D, Cardosa MJ, McMinn P, Ooi MH. Virology, epidemiology, pathogenesis, and control of enterovirus 71. Lancet Infect Dis. 2010;10:778–90. doi: 10.1016/S1473-3099(10)70194-8.
    1. Mackenzie JS, Chua KB, Daniels PW, Eaton BT, Field HE, Hall RA, et al. Emerging viral diseases of Southeast Asia and the Western Pacific. Emerg Infect Dis. 2001;7:497–504. doi: 10.3201/eid0707.017703.
    1. Huang SW, Hsu YW, Smith DJ, Kiang D, Tsai HP, Lin KH, et al. Reemergence of enterovirus 71 in 2008 in taiwan: dynamics of genetic and antigenic evolution from 1998 to 2008. J Clin Microbiol. 2009;47:3653–62. doi: 10.1128/JCM.00630-09.
    1. Dong C, Liu L, Zhao H, Wang J, Liao Y, Zhang X, et al. Immunoprotection elicited by an enterovirus type 71 experimental inactivated vaccine in mice and rhesus monkeys. Vaccine. 2011;29:6269–75. doi: 10.1016/j.vaccine.2011.06.044.
    1. Wang F-c. Epidemiological features of hand-foot-mouth disease in Jingxi county of Guangxi in 2008–2012 [Chinese] Chin Prev Med. 2014;15:62–6.
    1. Xie YH, Chongsuvivatwong V, Tang Z, McNeil EB, Tan Y. Spatio-temporal clustering of hand, foot, and mouth disease at the county level in Guangxi. China PLoS One. 2014;9:e88065. doi: 10.1371/journal.pone.0088065.
    1. Ooi EE, Phoon MC, Ishak B, Chan SH. Seroepidemiology of human enterovirus 71. Singapore Emerg Infect Dis. 2002;8:995–7. doi: 10.3201/eid0809.010397.
    1. Dai B, Chen ZH, Liu QC, Wu T, Guo CY, Wang XZ, et al. Duration of immunity following immunization with live measles vaccine: 15 years of observation in Zhejiang Province. China Bull World Health Organ. 1991;69:415–23.
    1. Musher DM, Manof SB, Liss C, McFetridge RD, Marchese RD, Bushnell B, et al. Safety and antibody response, including antibody persistence for 5 years, after primary vaccination or revaccination with pneumococcal polysaccharide vaccine in middle-aged and older adults. J Infect Dis. 2010;201:516–24. doi: 10.1086/649839.
    1. Fraser C, Tomassini JE, Xi L, Golm G, Watson M, Giuliano AR, et al. Modeling the long-term antibody response of a human papillomavirus (HPV) virus-like particle (VLP) type 16 prophylactic vaccine. Vaccine. 2007;25:4324–33. doi: 10.1016/j.vaccine.2007.02.069.
    1. Chang LY, King CC, Hsu KH, Ning HC, Tsao KC, Li CC, et al. Risk factors of enterovirus 71 infection and associated hand, foot, and mouth disease/herpangina in children during an epidemic in Taiwan. Pediatrics. 2002;109:e88. doi: 10.1542/peds.109.6.e88.
    1. Foo DG, Alonso S, Chow VT, Poh CL. Passive protection against lethal enterovirus 71 infection in newborn mice by neutralizing antibodies elicited by a synthetic peptide. Microbes Infect. 2007;9:1299–306. doi: 10.1016/j.micinf.2007.06.002.
    1. Zinkernagel RM, Bachmann MF, Kundig TM, Oehen S, Pirchet H, Hengartner H. On immunological memory. Annu Rev Immunol. 1996;14:333–67. doi: 10.1146/annurev.immunol.14.1.333.
    1. Ahmed R, Gray D. Immunological memory and protective immunity: understanding their relation. Science. 1996;272:54–60. doi: 10.1126/science.272.5258.54.
    1. Welsh RM, Selin LK, Szomolanyi-Tsuda E. Immunological memory to viral infections. Annu Rev Immunol. 2004;22:711–43. doi: 10.1146/annurev.immunol.22.012703.104527.
    1. Zeng M, El Khatib NF, Tu S, Ren P, Xu S, Zhu Q, et al. Seroepidemiology of enterovirus 71 infection prior to the 2011 season in children in Shanghai. J Clin Virol. 2012;53:285–9. doi: 10.1016/j.jcv.2011.12.025.
    1. Lin YL, Yu CI, Hu YC, Tsai TJ, Kuo YC, Chi WK, et al. Enterovirus type 71 neutralizing antibodies in the serum of macaque monkeys immunized with EV71 virus-like particles. Vaccine. 2012;30:1305–12. doi: 10.1016/j.vaccine.2011.12.081.
    1. Liang Y, Zhou X, Yang E, Pu J, Che Y, Wang J, et al. Analysis of the Th1/Th2 reaction in the immune response induced by EV71 inactivated vaccine in neonatal rhesus monkeys. J Clin Immunol. 2012;32:1048–58. doi: 10.1007/s10875-012-9690-3.
    1. Liu L, Zhang Y, Wang J, Zhao H, Jiang L, Che Y, et al. Study of the integrated immune response induced by an inactivated EV71 vaccine. PLoS One. 2013;8:e54451. doi: 10.1371/journal.pone.0054451.
    1. Pichichero ME. Booster vaccinations: can immunologic memory outpace disease pathogenesis? Pediatrics. 2009;124:1633–41. doi: 10.1542/peds.2008-3645.
    1. Brown BA, Oberste MS, Alexander JP, Jr, Kennett ML, Pallansch MA. Molecular epidemiology and evolution of enterovirus 71 strains isolated from 1970 to 1998. J Virol. 1999;73:9969–75.
    1. Arita M, Nagata N, Iwata N, Ami Y, Suzaki Y, Mizuta K, et al. An attenuated strain of enterovirus 71 belonging to genotype a showed a broad spectrum of antigenicity with attenuated neurovirulence in cynomolgus monkeys. J Virol. 2007;81:9386–95. doi: 10.1128/JVI.02856-06.
    1. Zhang H, An D, Liu W, Mao Q, Jin J, Xu L, et al. Analysis of cross-reactive neutralizing antibodies in human HFMD serum with an EV71 pseudovirus-based assay. PLoS One. 2014;9:e100545. doi: 10.1371/journal.pone.0100545.
    1. Huang ML, Chiang PS, Chia MY, Luo ST, Chang LY, Lin TY, et al. Cross-reactive neutralizing antibody responses to enterovirus 71 infections in young children: implications for vaccine development. PLoS Negl Trop Dis. 2013;7:e2067. doi: 10.1371/journal.pntd.0002067.
    1. Mao Q, Cheng T, Zhu F, Li J, Wang Y, Li Y, et al. The cross-neutralizing activity of enterovirus 71 subgenotype c4 vaccines in healthy Chinese infants and children. PLoS One. 2013;8:e79599. doi: 10.1371/journal.pone.0079599.
    1. Cardosa MJ, Perera D, Brown BA, Cheon D, Chan HM, Chan KP, et al. Molecular epidemiology of human enterovirus 71 strains and recent outbreaks in the Asia-Pacific region: comparative analysis of the VP1 and VP4 genes. Emerg Infect Dis. 2003;9:461–8. doi: 10.3201/eid0904.020395.

Source: PubMed

Sponsorzy i współpracownicy

Warunki medyczne

Interwencje lekowe

3
Subskrybuj