Feb. 28, 2007 -- An experimental hepatitis E vaccine shows promise but needs further study, experts report in The New England Journal of Medicine.
Hepatitis E is a liver disease caused by the hepatitis E virus, which spreads through contaminated food or water.
Hepatitis E is rare in the U.S., but it's a major public health problem in developing countries. The disease is most dangerous for pregnant women, who can die or have miscarriages or stillbirths due to hepatitis E.
The new vaccine doesn't have a brand name yet. If proven successful, a vaccine for hepatitis E could benefit people in hepatitis E-endemic countries and travelers to those regions.
Hepatitis E Vaccine Test
The vaccine study was conducted in Kathmandu, Nepal. Participants were 1,794 soldiers in Nepal's army.
Virtually all participants (99%) were men. No pregnant women took part.
None of the soldiers had previously contracted hepatitis E, but they were at high risk for hepatitis E infection, note the U.S. and Nepalese army experts who designed the study.
They included Mrigendra Prasad Shrestha, MBBS, of the U.S. Walter Reed-Armed Forces Research Institute of Medical Sciences Research Unit Nepal.
Half of the soldiers got three shots of the vaccine; the other half of the group got three sham shots (placebo). They were followed for the next six months.
Preventing Hepatitis E
During the six-month study, 69 participants developed hepatitis E. All but three of them had received the placebo shot, not the hepatitis E vaccine.
In people who got all three doses of the hepatitis E vaccine, the vaccine was 95% effective, the study shows.
Side effects were similar in both groups, though injection-site reactions were more common in the vaccine group. Infections (not including hepatitis E) accounted for most side effects, the study shows.
The vaccine's effectiveness and side effects beyond six months aren't yet clear.
The results are "encouraging," but the vaccine should be studied in pregnant women, children, and teens, writes editorialist Krzysztof Krawczynski, MD, PhD, of the CDC.
The vaccine may also be useful for people traveling from developed countries to areas where the hepatitis E virus is common, notes Krawczynski.
The study was funded by the drug company GlaxoSmithKline, which makes the vaccine and is a WebMD sponsor.