FDA approves four companies' H1N1 vaccines

Sep 15, 2009 (CIDRAP News) – The Food and Drug Administration (FDA) today announced approval of four of the five different versions of the pandemic H1N1 vaccine ordered by the US government, helping to pave the way for a vaccination campaign expected to start in October.

The FDA approved injectable vaccines made by CSL Limited, Novartis, and Sanofi Pasteur, and the nasal-spray vaccine made by MedImmune. The government also has ordered an H1N1 vaccine from GlaxoSmithKline (GSK), but today's announcement did not include the GSK vaccine.

The announcement comes a few days after the first preliminary clinical trial results indicated that one 15-microgram dose of the injectable vaccine generates a strong immune response in adults. Initial findings in children are still awaited.

The Novartis, Sanofi, and MedImmune vaccines are approved for both adults and children, while the CSL vaccine is indicated only for adults, FDA spokeswoman Peper Long told CIDRAP News today.

Long said the approvals call for two doses of vaccine given about a month apart for children younger than 9 or 10 years, depending on the manufacturer. One dose is indicated for older children and adults for all the vaccines, she said. The dosing recommendations for children will be updated if warranted by the results of the clinical trials, an FDA news release stated.

In the news release, FDA Commissioner Margaret A. Hamburg hailed the vaccine approvals as "good news for our nation's response to the 2009 H1N1 influenza virus," adding, "This vaccine will help protect individuals from serious illness and death from influenza."

In approving the vaccines, the FDA used the same process it uses in approving strain changes in seasonal flu vaccines.

"The H1N1 vaccines approved today undergo the same rigorous FDA manufacturing oversight, product quality testing and lot release procedures that apply to seasonal influenza vaccines," Jesse Goodman, MD, the FDA's acting chief scientist, said in the FDA release.

Long indicated that the vaccines approved today do not contain adjuvants (chemical additives to boost immune response). "Generally if there is a vaccine that is adjuvanted, that can't be licensed as a strain change supplement," she said.

Novartis and GSK are both testing H1N1 vaccines with and without adjuvants. No adjuvanted flu vaccines have been approved or used in the United States, and hence such products are expected to require additional safety review.

Long said she couldn't comment specifically on why GSK's vaccine was not included in today's approval, because the application is still under review.

MedImmune, unlike the other companies, has not yet reported any clinical trial results concerning immunogenicity for its vaccine, which uses a live but weakened virus. MedImmune spokeswoman Karen Lancaster said the company has preliminary findings indicating the vaccine has a safety profile like that of the company's licensed seasonal vaccine, FluMist, but the immunogenicity data are still awaited.

The FDA said the approved vaccines are being produced in formulations both with and without thimerosal, a mercury-containing preservative.

"In the ongoing clinical studies, the vaccines have been well tolerated," the agency said. "Potential side effects of the vaccines are expected to be similar to those of seasonal flu vaccines." People with severe allergies to chicken eggs should not be vaccinated, since the vaccines are grown in eggs, the FDA noted.

Regarding the dosing indications by age-group, Long said the approvals recommend the following, which are the same as for the companies' seasonal flu vaccines:

  • For the Novartis vaccine, 2 doses for children aged 4 through 8 years, and one dose for older children and adults
  • For the Sanofi vaccine, two doses for children aged 6 months through 8 years; one dose for older children and adults
  • For the MedImmune vaccine, two doses for children 2 through 9 years old; one dose for older children and for adults through age 49
  • For the CSL vaccine, one dose for adults (18 and older)

The Department of Health and Human Services (HHS) has ordered about 195 million doses of H1N1 vaccine. According to a recent federal report, Novartis is expected to contribute 45.7% of that, Sanofi 26.4%, CSL 18.7%, MedImmune 5.8%, and GSK 3.4%.

HHS officials have been predicting that the first 45 million doses will become available in mid October. Today HHS Secretary Kathleen Sebelius repeated that prediction, but told Congress that limited supplies should start trickling out in the first week of October, according to an Associated Press report.

Lancaster said MedImmune could make doses available before the end of this month, pending FDA lot releases and related instructions.

See also:

Sep 15 FDA announcement

Sep 15 Sanofi release

Sep 10 CIDRAP News story "Early results suggest 1 dose of H1N1 vaccine may be protective"

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