Hepatitis E vaccine successful in clinical trial: Study

By Dr. Ananya Mandal, MDAug 22 2010

In a Clinical trial in China, a vaccine has been found to protect against Hepatitis E. Hepatitis E virus, usually spread via contaminated food and faeces usually runs its course before the patient recovers. However it can cause severe illness in elderly people and has a mortality rate of 1 to 3 percent. It can also kill 5 to 25 percent of affected pregnant women and those who survive can suffer high rates of miscarriage. Around a third of the world's population have been infected by the virus say researchers.

This trial was a phase 3 trial involving 97,356 healthy participants in China's coastal province of Jiangsu. Half of these patients were given the China-made vaccine and the other half dummy medication. The trial vaccine, codenamed HEV 239, is a recombinant vaccine, meaning that it includes a protein from the virus designed to stimulate the body's immune defenses. Three doses of the vaccine were given. The second dose was given a month after the first and the third six months after the first dose. The vaccine is being developed by Xiamen Innovax Biotech.

Results were published in the International Journal Lancet. The trial results showed that within 1 year of the third dose, 15 of the participants who were given placebo were infected with hepatitis E. No one in the vaccine group was infected. No serious side effects were found to be linked to the vaccine.

The authors wrote, “In our trial, we found the vaccine well tolerated and efficacious for a general adult population. Further studies are needed to assess the safety and to support the benefits of the vaccine for pregnant women and for people younger than 15 years or older than 65 years…During a hepatitis E outbreak, or for travelers to an endemic area, protection can be quickly obtained by two vaccine doses given within one month.”

The trial was led by Ning-Shao Xia at the Institute of Diagnostics and Vaccine Development in Infectious Diseases in Xiamen University in southern Fujian province. The researchers said that more studies were needed to check the efficacy and safety of the vaccine in chronically ill patients like those with liver disease. More trials are needed on children and pregnant women as well.

The paper was accompanied by a comment from Scott Holmberg of the National Center for HIV, Hepatitis, TB and STD Prevention at the U.S. Centers for Disease Control and Prevention who said that this vaccine would be of great help in areas where sanitation was inadequate to prevent hepatitis E outbreaks. He said, “In view of the slow rate of improvement of sanitary conditions in many areas of Asia and Africa, this vaccine might be our best new ‘stopgap’ in the effort to control the scourge of HEV in many parts of the world.”