[Hepatitis A immunisation in the Argentinean mandatory schedule]

Area of Science:

• Hepatology
• Vaccinology
• Public Health

Context:

• Hepatitis A (HA) was a significant cause of acute liver failure (ALF) and hepatic transplant prior to 2005.
• A consensus recommended HA vaccine inclusion in the mandatory immunization schedule in 2003.
• The vaccination program commenced on June 1st, 2005, with a single dose at one year of age.

Purpose:

• To evaluate the impact of the universal Hepatitis A vaccination program implemented in Argentina.
• To assess the reduction in Hepatitis A incidence and severe outcomes like ALF.
• To monitor viral circulation and antibody persistence post-vaccination.

Summary:

• The implementation of a universal Hepatitis A vaccination program in Argentina led to a substantial decrease in HA cases.
• No cases of ALF attributed to Hepatitis A have been recorded since 2006 following the vaccine's introduction.
• Follow-up studies indicate sustained antibody levels up to five years and low viral circulation.

Impact:

• Demonstrates the effectiveness of a single-dose childhood vaccination schedule in controlling Hepatitis A.
• Significantly reduced the burden of severe Hepatitis A, including acute liver failure and the need for liver transplants.
• Provides evidence for the long-term immunological protection and epidemiological control achieved through widespread immunization.