Aug 16, 2007 (CIDRAP News) – The British pharmaceutical company GlaxoSmithKline (GSK) recently announced another major order of prepandemic H5N1 influenza vaccine from the US Department of Health and Human Services (HHS), along with plans to launch a North American clinical trial of the vaccine.
HHS ordered enough vaccine in bulk form to provide 22.5 million 15-microgram (mcg) doses, the company announced on Aug 3. The order is in addition to the bulk equivalent of 5 million 15-mcg doses that HHS ordered in November 2006, officials said.
The cost of the new vaccine order is $97 million, according to Marc Wolfson, a spokesman for the HHS Office of the Assistant Secretary for Preparedness and Response in Washington, DC.
The new order includes 9 million doses produced in the 2006 "manufacturing campaign" and 13.5 million doses to be produced in the 2007 campaign, GSK reported. The vaccine is based on clade 2 strain of the H5N1 virus.
GSK will make the bulk vaccine at its facility in Ste. Foy, Quebec, and store it in Marietta, Pa.
When HHS announced the plan to buy H5N1 vaccine from GSK in November 2006, the agency said it was ordering 800,000 doses, not the 5 million doses cited in the company's Aug 3 announcement. Wolfson of HHS and Ken Inchausti, a GSK spokesman in Philadelphia, explained that the two announcements involve the same amount of bulk vaccine, but the HHS statement was based on a dose of 90 mcg, whereas the company announcement assumed a dose of 15 mcg.
"The confusion between the 5 million doses that GSK talks about and what we have is that we're still ordering it at the bulk rate of 90 [mcg] per dose," Wolfson told CIDRAP News. "They're doing tests that could possibly take it down to 15 [mcg] per dose, and if you do the math, that's where the difference comes."
Based on 90 mcg per dose, HHS currently has 2.3 million doses of GSK vaccine in its H5N1 vaccine stockpile, Wolfson reported.
The vaccine contract provides that HHS may direct the company to formulate the bulk vaccine into doses in the future, GSK said. In addition, HHS has an option to buy the vaccine in combination with one of the company's proprietary adjuvants, or immune-boosting chemicals, which could reduce the amount of vaccine antigen needed to induce a protective immune response, the company reported.
Funds for the vaccine contract will come through the Biomedical Advanced Research and Development Authority (BARDA) in the HHS Office of the Assistant Secretary for Preparedness and Response, according to GSK.
Clinical trial starting
GSK also announced the start of the first North American clinical trial of its prepandemic H5N1 vaccine. The trial is described as a phase1/2 study that will compare the safety and immunogenicity of the H5N1 antigen alone and in combination with one of GSK's adjuvant systems in 675 adult volunteers. Inchausti said the trial will be conducted at sites in Montana, California, Florida, Georgia, Alabama, Kansas, and Nevada and in Halifax and Quebec, Canada.
The company said it plans to follow up later this year with a phase 3 trial that will involve about 4,400 volunteers. Results of the phase 1/2 trial are expected in early 2008.
Last March, GSK reported that in a clinical trial, one of its adjuvanted H5N1 vaccines triggered a strong immune response with two 3.8-mcg doses, or about half of the 15-mcg dose typically used for each viral strain in seasonal flu vaccines. The company also said tests showed that the vaccine, based on a Vietnam strain of H5N1, generated cross-reactive immunity against an Indonesian strain.
GSK, Baxter sign vaccine deals with UK
In other developments, both GSK and US-based Baxter International today announced agreements to sell vaccine to the United Kingdom in the event of a flu pandemic.
Under the GSK agreement, the company will make preparations to provide a "tailored" vaccine as soon as possible after a pandemic is declared by the World Health Organization, according to a company news release. GSK said it also has agreements to sell pandemic vaccines to Switzerland, Denmark, and Iceland.
Baxter, based in Deerfield, Ill., said its European subsidiary in the UK signed an agreement giving the UK an option to buy Baxter's vaccine in the event of a pandemic. The company's candidate pandemic vaccine is produced in vero cell culture rather than in eggs, the conventional medium for flu vaccine production. Baxter said it recently enrolled volunteers for a phase 3 clinical study of its cell-based H5N1 vaccine in Europe.
See also:
Mar 6 CIDRAP News story "Glaxo H5N1 vaccine may work against multiple strains"
Nov 20, 2006, CIDRAP News story "HHS awards 3 contracts for more H5N1 vaccine"
