Hepatitis A is an infection of the liver caused by the hepatitis A virus. It is generally mild in children, but the severity of the disease tends to increase with age. There are three types of hepatitis A vaccine; a vaccine for hepatitis A only, a combination vaccine to protect against hepatitis A and hepatitis B, and a combination vaccine to protect against hepatitis A and typhoid. Two doses of the hepatitis A vaccine, or the hepatitis A and typhoid combination vaccine are needed for long-term protection, with the second dose given 6 to 12 months after the first dose. The standard hepatitis A and hepatitis B combination vaccines require two or three doses, depending upon which vaccine is offered. In some countries, only one dose of the hepatitis A vaccine is given – this is informed by multiple studies that looked at the long-term protection offered by a single dose of the vaccine. See the more information section below. |