"These results are not unexpected and are both similar to what is seen with seasonal influenza vaccines and consistent with what we and our colleagues at the Food and Drug Administration anticipated," notes Dr. Fauci.

Study investigators are also collecting blood samples from the volunteers approximately three weeks after both the first and second injections. It is anticipated that the immune response to the 2009 H1N1 influenza vaccine will be similar to that of seasonal influenza vaccination and will continue to rise for several weeks following vaccination, says Dr. Fauci. The study is being closely monitored by the trial physicians and staff as well as by an independent safety monitoring committee.

The vaccine being tested in this trial is manufactured by Sanofi Pasteur in Swiftwater, Pa., in the same manner as its licensed seasonal vaccine, which is used every year in millions of children, and is the same formulation recently licensed by the FDA to protect against 2009 H1N1 influenza. Like inactivated seasonal influenza vaccines, the vaccine contains a purified part of a killed virus and cannot cause flu.

Source: NIH/National Institute of Allergy and Infectious Diseases