31 March 2009

FDA Licenses New Japa= nese B Encephalitis Vaccine =

On 30 March 2009 the U.S. Food and Drug Administration (FDA) licensed a new vaccine against Japanese B Encephalitis (named IXIARO and made by the U.K. company Intercell Biomedical). This will be the = only available vaccine in the USA because the former vaccine (“JE-VAX”) is no longer being manufactured.

Compared with the older JE-VAX vaccine, IXIARO is made using tissue culture techniques, requires one less dose, and overall “was more tolerable and had fewer side effects” according to the FDA licensure summary yesterday.

Japanese B encephalitis virus is a flavivirus tha= t is transmitted by mosquitoes, specifically Culex species. It is not spread from person to person. It is not endemic to the = USA. According to the CDC “Japanese Encephalitis Fact Sheet’ this virus occurs not only in parts of Asia but also northern Australia, has a case-fatality ratio of 30%= , and is the leading cause of viral encephalitis in Asia where 30,000-50,000 cases are reported each year.<= /o:p>

Most infections with this virus are subclinical. = It can, however, cause seizures, encephalitis, coma, as well as a very high ca= se fatality rate.

According to the acting director of the Center for Biologics Evaluation and Research (CBER) at the FDA, Karen Midthun, M.D. “This vaccine offers protection for individuals who travel or live in areas where outbreaks are known to occur”.

This IXIARO vaccine is an important addition to t= he list of available FDA-licensed vaccines, particularly for military deployed= to endemic parts of the world, expatriates and other residents living in certa= in (rural) endemic areas, and some travelers depending on the time of year and duration of exposure in endemic areas.

Danie= l R. Lucey, MD, MPH

EROne Institutes, Department of Emergency Medicine

Washington Hospital Center, Washi= ngton D.C.<= /o:p>

Georgetown University Medical<= /st1:PlaceName> Center<= /o:p>

Websi= te: www.BePast.org (requires Internet Explorer)<= /span><= /o:p>

e-mail: DRL23@Georgetown.edu