Hepatitis A Vaccine Best Bet to Treat Virus
THURSDAY Oct. 18, 2007 -- Treating the liver disease hepatitis A with the hepatitis A vaccine is as effective as treating it with the more traditional injection of immune globulin, a new study found.
Based on these results, the U.S. Centers for Diseases Control and Prevention's Advisory Committee on Immunization Practices now recommends the vaccine as the preferred treatment for the hepatitis A virus, according to a report in the CDC's Oct. 19 issue of its Morbidity and Mortality Weekly Report.
"The primary finding of the study is that hepatitis A vaccine appears to work equally as well as immune globulin after exposure to the virus," said lead researcher John C. Victor, with the Program for Appropriate Technology in Health, in Seattle.
For the vaccine to be effective as a treatment, just like immune globulin, it must be given within two weeks of exposure to hepatitis A. "Any longer than that is too late," Victor said.
The vaccine appears to work, because hepatitis A has a 28-day incubation period, so the vaccine has time to build immunity before the virus takes hold, Victor said.
In the study, Victor's team randomly assigned 1,090 people from Almaty, Kazakhstan, who had been exposed to hepatitis A to either a dose of the hepatitis A vaccine or immune globulin. All the study participants were between 2 and 40 years old, according to a report on the study in an Oct. 18 early release from the New England Journal of Medicine.
The researchers found that of all the people in the trial, 25 who received the vaccine and 17 who received immune globulin later showed symptoms of hepatitis A. Victor's group concluded that treatment with the vaccine is as effective as immune globulin.
The advantage of the vaccine is that it's readily available and has fewer side effects than immune globulin, Victor said. "Anyone who has had immune globulin will tell you it's not always a very fun shot. It's like getting injected with corn syrup, and it tends to cause a lot of local reaction and pain at the site of the injection," he said.
Immune globulin also offers only six months of protection, while the vaccine -- especially if one gets a second dose -- will protect for life, Victor said. "To ensure long-term protection, you need that second shot," he said.
Because of these factors, the CDC is recommending the hepatitis A vaccine to fight infection in those aged 12 months to 40 years who have been exposed to the virus. The CDC also recommends that people traveling to areas where hepatitis A is endemic get one dose of the vaccine. This single shot should protect most healthy people, the agency said.
Hepatitis A infects the liver and is spread through close personal contact, Victor said, including household contacts especially with young children, sexual contact, and shared needles among drug users. It can also be transmitted by food handlers who don't practice good hygiene. "This is a fecal-oral transmitted virus," he said.
Symptoms -- typically more prevalent in adults than children -- include jaundice, fatigue, abdominal pain, loss of appetite, nausea, diarrhea and fever. There's no long-term infection -- once you've had hepatitis A, you can't get it again. About 15 percent of people infected with the virus will have prolonged or relapsing symptoms over a six-to-nine month period, according to the CDC.
Young children have been vaccinated against hepatitis A since 1995, Victor said. As a result, incidence of the disease has dropped dramatically. "There are less than 5,000 cases a year now in the United States, where we used to have tens of thousands," he said.
Dr. Carol J. Baker, an infectious disease specialist at Baylor College of Medicine, wrote an accompanying editorial in the journal. She thinks the vaccination recommendation is worthwhile, because the vaccine is a better choice than immune globulin.
"This is another success for hepatitis A vaccine," Baker said. "Now we know that the vaccine is equally protective after exposure to the virus as immune globulin."
Baker thinks this is important, because there's only one manufacturer of immune globulin in the United States. "If anything happens, then there is no way to treat people exposed to the virus," she said.
Also, the cost of the vaccine is similar to immune globulin, Baker said, adding that with two doses of vaccine, you are protected for life.
For more on hepatitis A, visit the U.S. Centers for Disease Control and Prevention.
Posted: October 2007
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