Evaluation of hepatitis A vaccine in post-exposure prophylaxis, The Netherlands, 2004-2012.

Abstract

BACKGROUND:The secondary attack rate of hepatitis A virus (HAV) among contacts of cases is up to 50%. Historically, contacts were offered immunoglobulin (IG, a human derived blood product) as post-exposure prophylaxis (PEP). Amid safety concerns about IG, HAV vaccine is increasingly recommended instead. Public health authorities' recommendations differ, particularly for healthy contacts ≥40 years old, where vaccine efficacy data is limited. We evaluated routine use of HAV vaccine as an alternative to immunoglobulin in PEP, in those considered at low risk of severe infection in the Netherlands. METHODS:Household contacts of acute HAV cases notified in Amsterdam (2004-2012) were invited ≤14 days post-exposure, for baseline anti-HAV testing and PEP according to national guidelines: immunoglobulin if at risk of severe infection, or hepatitis A vaccine if healthy and at low risk (aged 40 years of age. In healthy contacts vaccinated per-protocol ≤8 days post-exposure, RR(ref. ≤15 years) of secondary infection in those >40 years was 12.0 (95%CI:1.3-106.7). CONCLUSIONS:Timely administration of HAV vaccine in PEP was feasible and the secondary attack rate was low in those 40 years of age and those vulnerable to severe disease.