TORONTO - Widescale production of a vaccine against the new H1N1 swine flu virus is likely and could be triggered by a call from the World Health Organization that could come as early as next week, the head of the agency's initiative for vaccine research said Wednesday.
The move might have an impact on seasonal flu shots, forcing some manufacturers to make some lots that do not include vaccine against influenza B viruses, Dr. Marie-Paule Kieny admitted in an interview.
"I would be really, really very surprised that it would not be large scale," Kieny said when asked whether swine flu vaccine production will go ahead and how large the effort is likely to be.
A number of countries with pandemic vaccine contracts will probably activate their purchase orders, she said, triggering a major switch to production of a new vaccine.
An expert panel that counsels the WHO on vaccines will meet May 14 to review the available science and advise WHO Director General Margaret Chan on whether to call on vaccine manufacturers to make a vaccine to protect against the new H1N1 virus.
Kieny said the WHO has already urged vaccine manufacturers to make all necessary preparations to go into production of a new vaccine, but has not yet decided on whether to ask them to stop production of seasonal flu vaccine.
It's estimated between 4,000 and 8,000 Canadians die every year from seasonal flu and its complications.
Authorities pondering decisions about the need for an H1N1 vaccine are weighing the impact any move might have on the production of seasonal flu vaccine for the Northern Hemisphere.
That process is currently underway, but is not completed. And, as is often the case with flu vaccine, production has hit some snags.
Reagents to test the concentration of influenza B component of the vaccine are not yet ready, leaving manufacturers unclear if they have enough to make all the trivalent -- triple component -- vaccine they have been contracted to make.
Seasonal flu shots protect against three types of influenza, the two human influenza A viruses that circulate (H3N2 and human H1N1) and one family of flu B viruses. Testing suggests the vaccine for the human H1N1 doesn't protect against the new swine virus.
Kieny said the expert panel will also be asked to advise on whether some manufacturers should be permitted to produce some bivalent -- two component -- vaccine for their seasonal run if it turns out they do not have enough influenza B vaccine.
"Is there a place for some bivalent (vaccine) if there's not enough trivalent?" she said of the questions they might be asked to ponder. "Are there specific populations for which a vaccine with a B would be more indicated than others?"
The U.S. Food and Drug Administration's acting chief scientist and deputy commissioner for scientific and medical programs said regulators may have to work with manufacturers on licensure issues if that is the case.
"I know there have been challenges with the B strain this year," Dr. Jesse Goodman said in an interview.
"I'm hopeful that the normal trivalent production will proceed. But if manufacturers were to come to us with issues, we'll work with them to address them."
