title: Protection against hepatitis E virus infection by naturally acquired and vaccine-induced immunity.
abstract: Immunity acquired from infection or vaccination protects humans from symptomatic hepatitis E. However, whether the risk of hepatitis E virus (HEV) infection is reduced by the immunity remains unknown. To understand this issue, a cohort with 12 409 participants randomized to receive the hepatitis E vaccine Hecolin(®) or placebo were serologically followed up for 2 years after vaccination. About half (47%) of participants were initially seropositive. A total of 139 infection episodes, evidenced by four-fold or greater rise of anti-HEV level or positive seroconversion, occurred in participants who received three doses of treatment. Risk of infection was highest among the baseline seronegative placebo group participants (2.04%). Pre-existing immunity and vaccine-induced immunity lower the risk significantly, to 0.52% and 0.30%, respectively. In conclusion, both vaccine-induced and naturally acquired immunity can effectively protect against HEV infection.
authors.affiliation: National Institute of Diagnostics and Vaccine Development in Infectious Diseases, School of Public Health, Xiamen University, Xiamen, China.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: X-F
authors.initials: XF
authors.lastname: Zhang
authors.forename: C
authors.initials: C
authors.lastname: Zhou
authors.forename: Z-Z
authors.initials: ZZ
authors.lastname: Wang
authors.forename: S-J
authors.initials: SJ
authors.lastname: Huang
authors.forename: X
authors.initials: X
authors.lastname: Yao
authors.forename: Z-L
authors.initials: ZL
authors.lastname: Liang
authors.forename: T
authors.initials: T
authors.lastname: Wu
authors.forename: J-X
authors.initials: JX
authors.lastname: Li
authors.forename: Q
authors.initials: Q
authors.lastname: Yan
authors.forename: C-L
authors.initials: CL
authors.lastname: Yang
authors.forename: H-M
authors.initials: HM
authors.lastname: Jiang
authors.forename: H-J
authors.initials: HJ
authors.lastname: Huang
authors.forename: Y-L
authors.initials: YL
authors.lastname: Xian
authors.forename: J W-K
authors.initials: JW
authors.lastname: Shih
authors.forename: M-H
authors.initials: MH
authors.lastname: Ng
authors.forename: Y-M
authors.initials: YM
authors.lastname: Li
authors.forename: J-Z
authors.initials: JZ
authors.lastname: Wang
authors.forename: F-C
authors.initials: FC
authors.lastname: Zhu
authors.forename: N-S
authors.initials: NS
authors.lastname: Xia
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D016751:Hepatitis E / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control*; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos / Q000008:administration & dosage; D018570:Risk Assessment; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology*; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000276:immunology*; D055815:Young Adult
chemical_list: D010919:Placebos; D014614:Vaccines, Synthetic; D014761:Viral Hepatitis Vaccines; C577000:hecolin
keywords: Antibody level; hepatitis E virus; immunity; infection; vaccine