Effectiveness of hepatitis A vaccination as post-exposure prophylaxis

Abstract

Hepatitis A (HA) has been a vaccine-preventable disease since 1995. In Catalonia, a universal combined hepatitis ACB vaccination program of preadolescents was initiated at the end of 1998. However, outbreaks are reported each year and post-exposure prophylaxis (PEP) with hepatitis A virus (HAV) vaccine or immunoglobulin (IG) is recommended to avoid cases.The aim of this study was to assess the effectiveness of HAV vaccine and IG in preventing hepatitis A cases in susceptible exposed people.A retrospective cohort study of contacts of HA cases involved in outbreaks reported in Catalonia between January 2006 and December 2012 was made. The rate ratios and 95% confidence intervals (CI) of HA in susceptible contacts receiving HAV or IG versus those without PEP were calculated.There were 3550 exposed persons in the outbreaks studied: 2381 received one dose of HAV vaccine (Hepatitis A or hepatitis ACB), 190 received IG, and 611 received no PEP. 368 exposed subjects received one dose of HAV vaccine and IG simultaneously and were excluded from the study. The effectiveness of PEP was 97.6% (95% CI 96.2-98.6) for HAV vaccine and 98.3% (95% CI 91.3-99.9) for IG; the differences were not statistically significant (p D 0.36).The elevated effectiveness of HAV vaccination for PEP in HA outbreaks, similar to that of IG, and the long-term protection of active immunization, supports the preferential use of vaccination to avoid secondary cases.

Type A viral hepatitis: A summary and update on the molecular virology, epidemiology, pathogenesis and prevention

“…183 Several reports confirmed the effectiveness of PEP using an inactivated HAV vaccine. 173,[184][185][186][187] Although controlled clinical trials have not been published in subjects aged 41 years and older, clinical experience from previous trials suggest that such a policy will also be effective in individuals older than 40 years old. 188 PEP through active vaccination is restricted to formalin-inactivated vaccines and should not be used with live attenuated vaccines.…”

Incidence of acute hepatitis A among HIV‐positive patients during an outbreak among MSM in Taiwan: Impact of HAV vaccination

“…The effectiveness of HAV vaccination in the outbreak setting has rarely been evaluated in high‐risk populations before. In a retrospective study focusing on post‐exposure prophylaxis for individuals who had exposure to index HAV cases during an outbreak, Parron et al . found that HAV vaccination resulted in a 97.6% reduction of secondary cases.…”

“…HAV vaccines, with or without HAV immune globulin, are also recommended by international guidelines for post‐exposure prophylaxis . Recently, Parron et al . reported using HAV vaccination as post‐exposure prophylaxis during outbreaks for patients exposed to index cases of acute hepatitis A, with an estimated efficacy of 97.6%.…”

Hepatitis A Virus in men who have sex with men: Need for awareness and vaccination

“…Such Taiwanese experience is paradigmatic of the central role that vaccination holds in the current epidemic control and further outbreaks prevention. Additionally, HAV vaccination as post‐exposure prophylaxis was found to protect with high efficacy (97.6%) in exposed individuals and comparable to anti‐HAV immunoglobulins …”