Taiwanese researchers report a 90% reduction in deaths from complications of hepatitis B since the country began its infant vaccination programme in 1984.
Vaccinations have also decreased the spread of hepatitis B, which can cause liver damage, liver cancer and a deadly reaction in babies called infant fulminant hepatitis, the researchers said.
"Immunisation has provided 30-year protection against acute hepatitis and end-stage chronic liver diseases, including cirrhosis and liver cancer," said lead researcher Chien-Jen Chen, a vice president at the Genomics Research Center at Academia Sinica in Taipei.
The implications of the findings are global.
Chen said there are 350 million chronic carriers of hepatitis B in the world, with the highest prevalence in the Asia-Pacific region and sub-Saharan Africa. The infection can be spread from mothers to newborns.
"All newborns in high-prevalence areas should be vaccinated to reduce the liver disease burden and health care costs," he said.
The report was published in the September 4 issue of the Journal of the American Medical Association.
The need for vaccination
According to the Hepatitis B Foundation, 12 million Americans have been infected with the disease, one out of every 20 people. In addition, more than 1 million people are chronically infected and up to 100 000 new infections occur each year.
The foundation estimates that 5 000 people in the United States die each year from hepatitis B and its complications.
The new findings add even more support for the need for vaccination, a US expert said.
"This is an exclamation point of what we already knew – that infants should be vaccinated against hepatitis B," said Dr Marc Siegel, an associate professor of medicine at the NYU Langone Medical Center in New York City. "Vaccination of infants with hepatitis B vaccine, which is highly effective, leads to a dramatic decrease in chronic infection and liver cancer, which are outcomes for up to 50% of those with hepatitis B."
In addition, vaccination builds herd immunity as fewer people are infected, thus reducing the spread of the disease in the population, Siegel said. "Everybody should be vaccinated against this virus," he said. "Infants and all adults should be vaccinated."
The hepatitis B vaccine is safe, Siegel said. "The disease is scary, the vaccine is not," he said.
For the study, Chen's team looked at the 30-year outcomes of the immunisation program in Taiwan. For the first two years, the immunisation programme covered only newborns of mothers who carried the disease. Then it expanded to all newborns.
In July 1987, vaccinations were extended to cover preschoolers. Between 1988 and 1999, the programme was extended to cover all elementary school children.
The rate of vaccinations for those born from 1984 to 2010 was about 89% to 97%, the researchers found.
For those born between 1977 and 2004, a more than 90% reduction occurred in deaths from chronic liver disease and liver cancer, and there were 80% fewer cases of liver cancer overall.
Deaths from infant fulminant hepatitis B also decreased 90%.
Hepatitis B is spread when blood, semen or other body fluids infected with the virus enters the body of an uninfected person, according to the US Centers for Disease Control and Prevention.
The infection can be transmitted from an infected mother to her newborn. The hepatitis B virus also can be transmitted during sex with an infected person or by sharing needles, syringes or other drug-injection equipment.
Sharing razors or toothbrushes with an infected person also can transmit the disease, as can direct contact with blood or open sores of an infected person, according to the CDC.
For more about hepatitis B, visit the U.S. Centers for Disease Control and Prevention.