It is not clear whether drug companies other than the two that announced their bids had entered the chase.
"We're not able to say who actually provided a proposal, other than that we did have multiple offers and they look pretty good," said Robin Robinson, director of the HHS Biomedical Advanced Research and Development Authority.
"They will be evaluated for technical merit over the next several weeks. Then we will enter into negotiations, and we're looking toward contracts by the fall," he said. The agency expects to award multiple contracts, "so if one doesn't make it, others will still be going forward."
Robinson said the department eventually expects to spend $1.5 billion acquiring anthrax vaccines for its stockpile.
The inventory is stored in undisclosed locations around the country. Robinson said it includes two types of antibiotics to prevent illness in up to 60 million people potentially exposed to an anthrax release. Those drugs are "ready to go," he said.
In addition, the stockpile has acquired anti-toxins to treat or prevent illness after anthrax exposure. There's enough now to treat about 20,000 people, Robinson said. Several companies are under contract to produce more.
To be ready to immunize people months or years before a potential exposure, HHS policy requires that the stockpile acquire enough anthrax vaccine for 25 million people, Robinson said, "and ultimately we would like to have enough for 300 million people."
So far, he said, there are just 18.2 million doses of BioThrax in the stockpile, enough for 3 million to 6 million people. It is the only anthrax vaccine currently licensed by the Food and Drug Administration.
"We're buying all that they can make until we have more vaccines available," Robinson said.
First licensed in 1970, BioThrax is produced using traditional methods, from the killed remains of the whole anthrax bacteria. But the vaccine has several drawbacks that the National Institute of Medicine and HHS believe more modern vaccines can eliminate.
Side effects, thought to be caused by fragments of the killed bacteria that do not help to produce immunity, include headaches, fever, swelling and pain at the injection site, nausea and dizziness, Wright said. Six percent of the reactions are considered serious.
In addition, the need for six injections over 18 months "makes it a very difficult vaccine to administer," Robinson said. "You have to keep track of everyone and make sure they're receiving all the doses they're supposed to. It's not what you'd call the optimum vaccine strategy."
