Hepatitis E Vaccine

Hepatitis E vaccine is a vaccine used to prevent hepatitis E, a liver infection caused by the hepatitis E virus that spreads mainly through the fecal-oral route, similarly to hepatitis A, although the two viruses are unrelated. Hepatitis E usually follows a self-limiting course with low death rates in resource-rich areas, but can be markedly more severe in pregnant women, especially in the third trimester, where it is associated with a fulminant liver failure syndrome carrying a death rate around 20 percent. A vaccine based on recombinant viral proteins was developed in the 1990s and tested in a high-risk population in Nepal in 2001, and appeared effective and safe, but its development was stopped for lack of profitability since hepatitis E is rare in developed countries, and no hepatitis E vaccine is licensed for use in the United States. In China, a vaccine developed by Chinese scientists and called HEV 239, made by Xiamen Innovax Biotech, was approved for the prevention of hepatitis E in 2012 by the Chinese Ministry of Science and Technology, following a controlled trial of more than 100,000 people in Jiangsu Province in which none of those vaccinated became infected over twelve months, compared with 15 cases among those given a placebo. As of 2015 the World Health Organization had not recommended routine use of the HEV 239 vaccine, citing a lack of evidence, leaving national authorities to decide based on local epidemiology, but the vaccine is on the World Health Organization's List of Essential Medicines.