Universal mass vaccination against hepatitis A.

Area of Science:

• Hepatology
• Vaccinology
• Public Health

Background:

• Hepatitis A virus (HAV) poses a significant disease burden.
• Initial hepatitis A vaccine recommendations targeted high-risk groups, with limited population-level impact expected.
• HAV epidemiology and disease burden necessitate effective control strategies.

Purpose of the Study:

• To review the virology, epidemiology, and disease burden of HAV.
• To describe the development and implementation of hepatitis A vaccination programs.
• To evaluate the impact of mass vaccination on HAV incidence and herd immunity.

Main Methods:

• Survey of HAV virology and epidemiology.
• Review of hepatitis A vaccine development (live and killed vaccines).
• Description of mass vaccination programs in Israel, Bahrain, Australia, China, Byelorussia, Italy, Spain, and the US.

Main Results:

• Mass vaccination programs led to spectacular reductions in HAV incidence in vaccinated cohorts and the general population.
• Evidence confirms that hepatitis A vaccination confers herd immunity when key spreaders are immunized.
• Pharmacoeconomic studies indicate cost-effectiveness for HAV control.

Conclusions:

• Mass hepatitis A vaccination is a highly effective strategy for reducing disease incidence and achieving herd immunity.
• Hepatitis A eradication is conceivable due to durable vaccine-induced immunity, potentially easier than polio eradication.
• Widespread adoption of mass vaccination programs is encouraged for HAV control and potential eradication.