HBV vaccine gets a 25-year boost

Encouraging news about the hepatitis B vaccine: Vaccination at birth appears to protect against the virus well into adulthood, according to a new study from Taiwan. The results suggest that booster shots in adulthood are not necessary.

Nearly four million people world wide are newly infected with the hepatitis B virus (HBV) every year. The virus, which spreads via blood and other bodily fluids, often leads to liver cancer. In 1984, Taiwan chose to mandate HBV vaccination at birth, because of the island's high rates of infection and liver cancer. The latest study, just published in the Journal of Hepatology, drew from Taiwan's own striking data on the vaccine's efficacy.

Because of Taiwan's HBV vaccination law, the population is ideal for an observational study. Led by a researcher at National Taiwan University, the study included more than 3,300 participants, all under the age of 30. More than 2,900 of these subjects had received the necessary doses of the HBV vaccine in their first year, while the rest, who were born before the mandate, had not.

By collecting blood samples over the course of a year, the researchers found that there was indeed a disparity between those who had been vaccinated, and those who had not. While less than 1 percent of the vaccinated participants carried the virus, 10 percent of those who hadn't been vaccinated were infected with hepatitis B. Significantly, most cases of vaccine failure among the universally vaccinated were due to the mother passing the virus to her baby. The researchers also found that, among immunized participants over age 20, the infection rate did not increase significantly from 1989 to 2009 leading them to conclude that a booster dose of the vaccine is not typically necessary at least for 25 years.

The Taiwanese study bolsters U.S. recommendations that babies should be immunized against HBV at birth, notes ACSH's Dr. Gilbert Ross. Despite this recommendation and the vaccine's availability, the Centers for Disease Control and Prevention (CDC) reports that 80,000 individuals are infected with HBV each year in the U.S. Furthermore, liver disease kills nearly 5,000 chronically infected people annually in this country a rate that will not decline without an improvement in the vaccination rate.