TORONTO - Tough choices were on the table as experts that counsel the World Health Organization on vaccine issues met Thursday to discuss the pros and cons of making swine flu vaccine.
Dr. Marie-Paule Kieny, the head of the agency's vaccine research initiative, has already said she expects wide-scale production of a vaccine for the new H1N1 swine flu virus to be given a green light.
But balancing the need for the new product and the need for vaccine to protect against seasonal flu strains that are still circulating will make for a difficult balancing act, experts said.
"The tradeoff here is to what extent would asking the manufacturers to make large amounts of an H1 vaccine detract from their ability to generate the required amount of seasonal vaccine?" said Dr. John Treanor, an influenza vaccine expert at the University of Rochester in New York State.
"It's certainly conceivable that there would be some impact on seasonal vaccine manufacturing if you start trying to make large amounts of the H1 vaccine. So you've got to decide: Is that on balance worth going ahead and accepting that issue so that you have an H1 vaccine ready?"
"And I suspect given what's happened ... that most governments or whoever is in charge of making this decision will go ahead and tell the manufacturers to divert some of their resources to making an H1 vaccine."
The WHO's leading influenza expert suggested the uncertainty inherent in the current situation makes the questions about vaccine production "enormously complicated." And Dr. Keiji Fukuda said answers to all of the pending questions cannot be arrived at in a single meeting.
By the end of the day Geneva time a spokesperson for Kieny's office said discussions were still underway and no announcements would be made Thursday.
Fukuda and others have suggested vaccine decisions can and should be made on a step-wise basis. The first step - telling vaccine makers to get ready to receive the order to make vaccine - has already been taken.
Several laboratories are making seed strains, the modified viruses most manufacturers use to start growing commercial lots of vaccine. It is believed at this point none of the seed strains will be ready to transfer to manufacturers before the end of the month.
Once the seed strains are available, manufacturers have to start working with the new virus, a process that invariably demands that they tweak their procedures to ensure high yield. Then they will have to produce pilot lots that can be used in clinical trials to determine that the vaccine is safe, how large a dose is required and whether people need one dose or two to be protected.
Those processes buy time for the WHO and governments to watch the new virus and see how it behaves as flu season moves from the Northern to the Southern Hemisphere.
"As the H1 situation unfolds we will get a better and better handle on what is the severity, what is the impact on people," said Fukuda, acting assistant director general for health security and environment.
"And it will give us more information (with which) to make these difficult decisions. Because what is really going to be wrestled with is that seasonal influenza itself has a significant impact on people."
"This is not a benign infection," he said of seasonal flu.
"This is an infection which again is estimated to kill some hundreds of thousands of people each year around the world. So there's a real tradeoff if you just say: We are going to stop making that vaccine."
Canada has a long-term contract, now held by vaccine giant GlaxoSmithKline, to buy enough pandemic vaccine to protect all Canadians who want to be vaccinated. The vaccine would be made at GSK's manufacturing facility in Ste-Foy, Que.
The Public Health Agency of Canada has said it is in discussions with GSK about the possibility of making a vaccine to protect against this new H1N1 virus but has not yet said whether it will proceed with the work.