US cancels anthrax vaccine contract
Government won't have its desired stockpile of recombinant-based vaccine for at least another three years
The US government has cancelled its $877.5 million contract with VaxGen, Inc. for a new anthrax
vaccine, likely delaying by at least three years the creation of a recombinant-based stockpile sufficient to immunize 25 million Americans.
The Department of Health and Human Services (HHS) said this week that it had terminated its two-year-old contract with VaxGen
, a small San Francisco area biotech company, because the vaccine was unstable, breaking down too quickly over time for the government to allow it to be tested in clinical trials. VaxGen was two years behind in the delivery schedule for the vaccine, which called for the first third of the supply to be delivered by the end of this year, according to Marc Wolfson, an HHS spokesman.
Because the company did not deliver any vaccine, it never received any payment. "The $877.5 million is still in the US Treasury," Wolfson told The Scientist
. VaxGen did receive two 2003 grants from the National Institute for Allergy and Infectious Diseases (NIAID) totaling about $100 million, plus another $15 million from HHS to beef up its plant security, he said.
VaxGen has already spent over $175 million developing the vaccine, spokesman Lance Ignon told The Scientist
. In addition, because the contract holds VaxGen liable for any excess costs the government incurs because of its failure, if HHS signs a new contract with a different manufacturer for more than $877.5 million to make the same amount of vaccine, VaxGen could potentially be forced to pay the difference. Ignon said the company is exploring its legal and strategic options.
Although the cancellation delays the establishment of a recombinant-based stockpile of anthrax vaccine, Wolfson said it does not leave the US unprotected in the event of an anthrax attack. HHS believes the first line of defense is antibiotics, with a vaccine a second line, he said, adding that the current stockpile could provide a 60-day course of antibiotics for 40 million Americans.
In addition, HHS has already taken delivery of eight million doses of an older-version, non-recombinant anthrax vaccine manufactured by Emergent Biosolutions
and has ordered two million more doses, enough altogether to vaccinate 1.6 million people. HHS may order more of this vaccine in the future, Wolfson said.
Still, what the agency really wants to do is to develop another vaccine just like VaxGen's, but without the stability problems, he said. The UK-based company Avecia
currently has a candidate in phase II clinical trials. Avecia and VaxGen were awarded nearly duplicate grants
from NIAID in 2003 to develop recombinant protective antigen (rpa) vaccines, which confer immunity because they contain the so-called protective antigen in anthrax that can prevent its two major toxins
from causing sickness and death. Although VaxGen won the huge HHS contract, Avecia beat it to clinical trials with its more stable product.
VaxGen's rpa vaccine broke down prematurely because there was too little affinity between the rpa protein and the aluminum hydroxide adjuvant added to make the vaccine more potent, Ignon said. So far, Avecia's version hasn't exhibited any instability problems, said Michael Kurilla, NIAID's associate director of biodefense product development.
Even though the two vaccines used exactly the same antigen, differences in formulation and manufacturing processes made one more stable than the other. "Some of these strategies work and some don't," he said, and that can't be predicted in advance.
It would likely take Avecia "several years at least" to produce the desired stockpile of rpa vaccine if HHS awarded the company a contract, Kurilla said.
John Dudley Miller
Links within this article:
"Anthrax Acts in Surprising Ways," The Scientist
, March 1, 2006
VaxGen Cancellation Announcement
Emergent Biosolutions progress report
J.D. Miller, "Procurement compromise possible,"The Scientist
, July 1, 2003
V. Glaser, "Unlocking the secrets of anthrax toxicity," The Scientist
, Nov. 2, 2001