Hepatitis B Vaccine Protects Longer Than Thought

The vaccine for hepatitis B may provide protection longer than previously expected, according to new research.

The hepatitis B virus causes inflammation of the liver and can cause complications such as liver scarring or cancer. In most countries, the hepatitis B vaccine is recommended for infants. The vaccine has been shown to be effective in reducing the rate of chronic hepatitis B virus.

Previous research has suggested the vaccine for hepatitis B protects against infection for up to 10 years. However, a recent study has shown the vaccine protection continues past 10 years.

In Alaska, hepatitis B virus infection is common, so members of Alaska native communities are especially likely to benefit from vaccination. For these reasons, researchers from the National Center for Infectious Diseases, Centers for Disease Control and Prevention, and the Alaska Native Medical Center in Anchorage conducted a 15-year study in Alaska.

Eight-hundred-and-forty-one Alaska natives vaccinated with three doses of the hepatitis B vaccine were followed for 15 years. Researchers periodically took blood from the participants to measure hepatitis B antibodies and hepatitis virus levels.

After 15 years, researchers found 84 percent of the participants still had protective antibodies. Only three participants had become infected with hepatitis B virus during the 10- to 15-year follow-up period.

In conclusion, researchers found the hepatitis B vaccine protected most participants from infection and all participants from complications of infection for at least 15 years. The researchers say people younger than age 5 at the time of vaccination may be less protected and might benefit from booster doses.

In an accompanying editorial, a writer suggests the decision to administer booster doses after 15 years would depend on whether the primary goal of the vaccinations is to control infection in early infancy through high rates of primary vaccination or to prevent new cases of acute hepatitis B more than 20 years after childhood vaccination.

SOURCE: Annals of Internal Medicine, 2005;142:333-341