Hepatitis A vaccine
Hepatitis A Vaccine[edit]
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[edit]
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[edit]
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[edit]
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[edit]
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[edit]
Common side effects of the hepatitis A vaccine include soreness at the injection site, headache, and fatigue. Serious side effects are rare.
Recommendations[edit]
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
