Hepatitis A vaccine found to be helpful post-exposure treatment

By Glenna Picton

Most experts accept that the hepatitis A vaccine is effective in preventing infection with the virus that causes the liver disease.

However, a recent study in Kazakhstan showed that it can also prevent people exposed to the virus from becoming ill, giving doctors a new tool in protecting patients, said Carol Baker, M.D., professor of pediatrics and molecular virology and microbiology at BCM.

"Results from a recent study published in the New England Journal of Medicine demonstrate the value of the vaccine as a preventive treatment" if given within 14 days, she said. Baker authored an editorial evaluating the study and the vaccine's effect in The New England Journal.

There are about 1.5 million cases of hepatitis A worldwide, according to the World Health Organization. The disease is caused by the hepatitis A virus, which affects mainly the liver. It most often is transmitted by the fecal-oral route and is closely associated with poor sanitary conditions.

Partnered with the CDC

The study in the New England Journal was conducted in partnership with the U.S. Centers for Disease Control and Prevention.

"There are moderate to high rates of hepatitis A infection in the Kazakhstan community," Baker said. "There is plenty of infection in this country to do a valuable study like this."

The most common preventive treatment for hepatitis A exposure is a shot of an immune-stimulating agent called immunoglobulin.

"Depending on how big you are, this can be a big volume, very painful shot," Baker said.

Vaccine vs. immunoglobulin

In the study, patients were chosen at random to receive either immunoglobulin or the hepatitis A vaccine.

"Most people received the vaccine 10 days after exposure," Baker said. "But it has to be administered within 14 days or it does not work."

Both have proved effective as a post-exposure treatment with comparable rates of infection.

"The hepatitis A vaccine rate was 4.4 percent and in the immunoglobulin group it was 3.3 percent," Baker said. "This difference is not statistically significant."

Vaccine advantages

There are several advantages associated with using the hepatitis A vaccine.

"We have only one manufacturer of immunoglobulin in the United States," Baker said. "What are we going to do if there is a major outbreak and not enough vaccines to go around?"

Immunoglobulin provides temporary protection, whereas the vaccine is permanent.

"If those exposed get a second dose of the vaccine later, they get life-long protection," Baker said.

Price is also a factor. "The price of immunoglobulin is getting very close to the price of vaccines," Baker said.

European recommendations

"Most European countries already recommend the vaccine as a post-exposure treatment," Baker said. "We just waited for data, and now this will bring us in line with them."

"We have another way to prevent post-exposure," Baker said. "This is very important from a public health perspective."

Baker's editorial is available at http://content.nejm.org/cgi/content/full/357/17/1757.