Long-term efficacy of a hepatitis E vaccine.
Author(s): Zhang J(1), Zhang XF, Huang SJ, Wu T, Hu YM, Wang ZZ, Wang H, Jiang HM, Wang YJ,
Yan Q, Guo M, Liu XH, Li JX, Yang CL, Tang Q, Jiang RJ, Pan HR, Li YM, Shih JW,
Ng MH, Zhu FC, Xia NS.
Affiliation(s): Author information:
(1)From the State Key Laboratory of Molecular Vaccinology and Molecular
Diagnostics, National Institute of Diagnostics and Vaccine Development in
Infectious Diseases, Collaborative Innovation Center of Biologic Products, School
of Public Health, Xiamen University (J.Z., S.-J.H., T.W., J.W.-K.S., M.-H.N.,
N.-S.X.), and Xiamen Innovax Biotech Company (Q.Y., M.G., X.-H.L., H.-R.P.,
Y.-M.L.), Xiamen, Jiangsu Provincial Center for Disease Control and Prevention,
Nanjing (X.-F.Z., Y.-M.H., H.W., J.-X.L., F.-C.Z.), Dongtai Center for Disease
Control and Prevention, Dongtai (Z.-Z.W., H.-M.J., Y.-J.W., C.-L.Y.), and
Yancheng Center for Disease Control and Prevention, Yancheng (Q.T., R.-J.J.) -
all in China.
Publication date & source: 2015, N Engl J Med. , 372(10):914-22
BACKGROUND: Hepatitis E virus (HEV) is a leading cause of acute hepatitis. The
long-term efficacy of a hepatitis E vaccine needs to be determined.
METHODS: In an initial efficacy study, we randomly assigned healthy adults 16 to
65 years of age to receive three doses of either a hepatitis E vaccine (vaccine
group; 56,302 participants) or a hepatitis B vaccine (control group; 56,302
participants). The vaccines were administered at 0, 1, and 6 months, and the
participants were followed for 19 months. In this extended follow-up study, the
treatment assignments of all participants remained double-blinded, and follow-up
assessments of efficacy, immunogenicity, and safety were continued for up to 4.5
years.
RESULTS: During the 4.5-year study period, 60 cases of hepatitis E were
identified; 7 cases were confirmed in the vaccine group (0.3 cases per 10,000
person-years), and 53 cases in the control group (2.1 cases per 10,000
person-years), representing a vaccine efficacy of 86.8% (95% confidence interval,
71 to 94) in the modified intention-to-treat analysis, rather than (95%
confidence interval, 71 to 84) [corrected]. Of the participants who were assessed
for immunogenicity and were seronegative at baseline, 87% of those who received
three doses of the hepatitis E vaccine maintained antibodies against HEV for at
least 4.5 years; HEV antibody titers developed in 9% in the control group. The
rate of adverse events was similar in the two groups.
CONCLUSIONS: Immunization with this hepatitis E vaccine induced antibodies
against HEV and provided protection against hepatitis E for up to 4.5 years.
(Funded by the Chinese Ministry of Science and Technology and others;
ClinicalTrials.gov number, NCT01014845.).
Erratum in
N Engl J Med. 2015 Apr 9;372(15):1478.
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