FDA issues guidance on flu vaccine development

Jun 4, 2007 (CIDRAP News) – The US Food and Drug Administration recently released separate documents outlining the kinds of clinical data required for licensing of new seasonal and pandemic influenza vaccines.

In a May 31 news release, the agency said the guidance documents were designed to facilitate the rapid development and approval of new vaccines by outlining the regulatory pathways for companies.

The two documents reflect public input on draft versions that were released in March 2006, the FDA said. They outline approaches for developing vaccines that are "safe, pure, and potent."

"Both guidances recommend using recent technologies such as cell culture and recombinant manufacturing to enhance the development and evaluation of vaccines," the FDA statement said. "They also recommend adding substances that improve the immune response from the vaccine (adjuvants)."

The recommendations describe conventional and accelerated approaches to vaccine licensing. Companies that choose the conventional pathway must provide clinical evidence that the vaccine actually prevents flu.

With the accelerated pathway, a company still must conduct clinical trials but can use a biological indicator, such as antibody response, to predict the effectiveness of the vaccine, the FDA said. Companies will be expected to conduct additional clinical studies if and when the vaccine is used.

The guidance documents are part of the FDA's ongoing efforts to reduce the time it takes to translate scientific advances, such as cell culture–derived and recombinant vaccine technologies, into approved medical products, the agency said.

In April the FDA approved the nation's first human vaccine aimed at the pandemic threat posed by the H5N1 avian influenza virus. In a clinical trial, two doses of the vaccine, made by Sanofi Pasteur, yielded what was believed to be a protective immune response in 45% of volunteers. The vaccine is based on a 2004 strain of H5N1 virus from a human patient in Vietnam.

Despite the vaccine's limited efficacy as predicted by the clinical trial, federal officials hope that in the event of a pandemic involving an H5N1 virus, it would buy some time to develop a vaccine closely matched to the emerging pandemic strain. The Department of Health and Human Services is stockpiling the vaccine and had 13 million doses, or enough to vaccine 6.5 million people, on hand when the FDA approved it.

See also:

May 31 FDA news release
http://www.fda.gov/bbs/topics/NEWS/2007/NEW01645.html

FDA guidance on clinical data needed for licensing of seasonal inactivated flu vaccines
http://www.fda.gov/cber/gdlns/trifluvac.htm

FDA guidance on clinical data needed for licensing of pandemic flu vaccines
http://www.fda.gov/cber/gdlns/panfluvac.htm

Apr 17 CIDRAP News story "FDA approves H5N1 vaccine"