Hepatitis A vaccine

Hepatitis A Vaccine

Havrix, a brand of Hepatitis A vaccine

The Hepatitis A vaccine is a vaccine that prevents hepatitis A. Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus (HAV). The vaccine is effective in preventing the disease and is recommended for all children, travelers to certain countries, and others at risk.

History

The development of the hepatitis A vaccine began in the 1970s, with the first vaccines being licensed in the 1990s. The vaccine has significantly reduced the incidence of hepatitis A in countries where it is routinely administered.

Types of Vaccines

There are two main types of hepatitis A vaccines:

• Inactivated (killed) vaccines: These vaccines contain inactivated hepatitis A virus. Examples include Havrix and Vaqta.
• Live attenuated vaccines: These vaccines contain a live but weakened form of the virus. They are less commonly used.

Administration

The hepatitis A vaccine is typically administered as an injection into the muscle. It is given in two doses, with the second dose administered 6 to 12 months after the first. This schedule provides long-term protection against the virus.

Effectiveness

The vaccine is highly effective, with more than 95% of individuals developing protective antibodies after the first dose. The second dose ensures long-term protection, potentially lasting a lifetime.

Side Effects

Common side effects of the hepatitis A vaccine include soreness at the injection site, headache, and fatigue. Serious side effects are rare.

Recommendations

The Centers for Disease Control and Prevention (CDC) recommends the hepatitis A vaccine for:

• All children at age 1 year
• Travelers to countries where hepatitis A is common
• Men who have sex with men
• Users of recreational drugs
• People with chronic liver disease
• People with clotting-factor disorders
• People who work with hepatitis A virus in research settings

Related Pages

• Hepatitis A
• Vaccine
• Liver disease
• Centers for Disease Control and Prevention