Hepatitis A Vaccination (Adults)

About the Hepatitis A Vaccination (Adults)

Hepatitis A is a viral liver infection caused by the hepatitis A virus (HAV), transmitted primarily through ingestion of contaminated food or water and through close contact with an infected person. It is prevalent in regions with poor sanitation infrastructure, including much of sub-Saharan Africa, South and Southeast Asia, Central and South America, and the Middle East. Most people recover fully, but hepatitis A can cause debilitating illness for several weeks and, rarely, acute liver failure — particularly in older adults and those with pre-existing liver conditions.

The hepatitis A vaccine provides highly effective and long-lasting protection. A single dose administered before travel protects for approximately 12 months; a booster dose given 6 to 12 months later extends immunity to 25 years or more. A combined hepatitis A and B vaccine (Twinrix) is available for those requiring protection against both viruses.

Who should have this vaccination?

• Travellers to hepatitis A-endemic regions, including Asia, Africa, the Middle East, and Latin America
• Individuals with chronic liver disease, including those with hepatitis B or C infection
• Men who have sex with men
• People who inject drugs
• Those working in sewage handling, food preparation, or healthcare with potential hepatitis A exposure
• Individuals travelling to destinations with recent hepatitis A outbreaks

Vaccination schedule

The standard hepatitis A vaccination course for adults consists of two doses. The first dose provides protection from approximately two to four weeks after administration; a booster given 6 to 12 months later extends immunity significantly. The combined Twinrix vaccine (hepatitis A and B) is given as a three-dose course at 0, 1, and 6 months. An accelerated Twinrix schedule — 0, 7, and 21 days, with a 12-month booster — is available for travellers with little advance notice.