Persistence of Immunogenicity of a Single Dose of Live Attenuated Hepatitis A Vaccine: A Follow-up Study 20 Years After Vaccination

It is a Single-center longitudinal cohort 20 year follow up study. Subjects who received a single dose of live attenuated Hepatitis A vaccine in 2004 will assessed in this study. Subjects who fulfill the eligibility criteria mentioned above will be intimated by post, phone call, or home visit by the social worker. The participant will be invited to KEMHRC for the 20th year follow-up visit. During the visit, after the informed consent, participants will be asked for the history of hepatitis-like illness (fever, anorexia, nausea, vomiting, and jaundice). The clinical examination will involve checking for hepatomegaly or splenomegaly, if any. The subjects will be clinically assessed for evidence of hepatitis (if any). After routine clinical assessments, blood samples (~10 mL of venous blood from each subject) will be collected and sent to the partner laboratory to estimate the total anti-HAV antibodies. Any local reactions while collecting venous blood will be captured and reported. Data will be entered in predesigned paper case report forms (CRFs). All study documents will be maintained in a dedicated study cupboard with restricted access.