FDA Approves 4 H1N1 Vaccines and Expects Nationwide Distribution Next Month

Easing fears on whether—and how quickly—a vaccine to combat the 2009 H1N1 influenza virus will become available, the FDA this week approved 4 new vaccines to fight the virus and expects they will be distributed nationwide within the next 4 weeks.

The FDA-approved injectable vaccines are manufactured by CSL Biotherapies and Novartis Vaccines and Diagnostics (both approved for use in adults aged 18 and older) and Sanofi Pasteur (approved for those 6 months of age and older). The fourth—an intranasal vaccine—is manufactured by MedImmune and is approved for individuals 2 to 49 years of age.

Federal officials also are encouraged by preliminary data from clinical studies of the H1N1 vaccine conducted by various manufacturers which indicate that a single (15-mcg) dose of the vaccine induces a robust immune response in most healthy adults in about 8 to 10 days, as is the case with the vaccine for regular, seasonal flu. Previously, it was expected that the H1N1 vaccine would need to be administered in 2 doses, spaced approximately 4 weeks apart.

The FDA reports that clinical studies currently under way will provide additional information about the optimal dose in children. Recommendations for dosing will be updated if indicated by findings from these studies, which are expected soon.

All 4 firms manufacture the H1N1 vaccines using the same processes, which have a long record of producing safe seasonal influenza vaccines, according to the FDA. The agency’s chief scientist, Jesse Goodman, MD, said the approved H1N1 vaccines underwent “the same rigorous FDA manufacturing oversight, product quality testing, and lot release procedures that apply to influenza vaccines.”

As with seasonal flu vaccines, the 2009 H1N1 vaccines are being produced in formulations that contain thimerosal, a mercury-containing preservative, as well as in formulations that do not contain thimerosal.

Over the summer, the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices recommended that when an H1N1 vaccine becomes available, priority be given to the following 5 groups: pregnant women; individuals who live with or care for children <6 months of age; health care and emergency services personnel; persons between the ages of 6 months and 24 years of age; and adults aged 25 to 64 who are at higher risk for novel H1N1 because of chronic health disorders or compromised immune systems.

Officials also are reminding individuals that they can and should get vaccinated now against seasonal flu. Health professionals can find more information on both the H1N1 and seasonal flu vaccines at www.fda.gov/BiologicsBloodVaccines/.