Hepatitis A virus (HAV) superinfection in patients with cirrhosis can precipitate acute hepatic decompensation and significantly worsen outcomes. Although HAV exposure was historically universal in India, recent evidence shows declining natural immunity in adults, particularly in urban populations. Contemporary data on HAV seroprevalence and vaccine immunogenicity in Indian cirrhotics remain scarce. Updated evidence is necessary to inform national vaccination policy for chronic liver disease.

This study aims to estimate the prevalence of anti-HAV IgG among adults with cirrhosis and identify predictors of non-immunity. A secondary objective is to evaluate early immunogenicity and durability of a single dose of inactivated HAV vaccine in baseline non-immune patients.

This study will generate updated sero-epidemiological data and prospective evidence on single-dose HAV vaccine immunogenicity in Indian cirrhotics, providing essential guidance for HAV vaccination policies in cirrhosis.

STUDY DESIGN: Observational cross-sectional study with a nested prospective cohort.

Inclusion Criteria:

1. >18 years of age with cirrhosis.
2. Anti-HAV IgG negative at screening.
3. No prior HAV vaccination.

Exclusion Criteria:

1. Unable/unwilling to consent.
2. Pregnant patients.
3. Clinically unstable.

Adult patients with cirrhosis attending outpatient clinics or admitted to ILBS, New Delhi.