Canada's strategy to vaccinate its entire population against the pandemic H1N1 virus has come under attack by the country's leading medical journal. It warns that Canadians with the highest risk of developing the potentially fatal flu are more likely to fall victim because they won't receive shots as quickly as others elsewhere in the world.
The United States, Australia and other European countries intend to disseminate the medication by October to high-risk groups, which include children and pregnant women. Canadians, however, won't be injected until mid-November.
That's because the federal government will use an adjuvant – a chemical additive that boosts supplies – in its vaccine, a move that requires it to cross more regulatory hurdles before mass vaccination.
The tactic that they've taken needs to be adjusted to ‘Let's vaccinate first and foremost the high-risk groups and then we'll see.' — Paul Hébert, editor-in-chief, Canadian Medical Association Journal
The adjuvant vaccine allows Ottawa to deliver on its pledge of offering the drug to all Canadians who need and want it. But the Canadian Medical Association Journal argued Monday that the later the vaccine arrives, the lower the chances of it protecting vulnerable groups before the epidemic season peaks.
Health authorities should roll out non-adjuvant vaccine for children, pregnant women and aboriginal communities, the same course being taken by the United States and Europe, while the rest of the population can wait for the adjuvant vaccine, the journal suggested.
“Do you need to vaccinate the whole population or primarily high risk groups?” Paul Hébert, editor-in-chief, asked in an interview Monday. “Vaccinating the whole population would be the right strategy if this was mutating into something horrible, and it's not. The tactic that they've taken needs to be adjusted to ‘Let's vaccinate first and foremost the high-risk groups and then we'll see.' ”
The virus, which has killed 72 Canadians, disproportionately affects younger people, unlike seasonal flu which mainly burdens the elderly. Health officials believe that while young people have been exposed to other flu strains they don't respond as well to H1N1 as those born before 1957 and whose first experience was with this strain.
Canada has ordered 50 million doses from GlaxoSmithKline, which is contracted to produce pandemic flu vaccine for all Canadians at its Ste-Foy, Que., plant. The use of adjuvants means the company could produce vaccines using less seed stock, which is important given the low yield to date. Glaxo plans to use an adjuvant system called AS03.
Two women are given masks as they arrive at a swine flu treatment facility for the collection of Tamiflu antiviral drug in east London, Tuesday, July 21, 2009. Health officials in Britain have issued a torrent of conflicting advice on swine flu, telling people to avoid travel, stay away from crowds and even advising women to delay getting pregnant until the virus subsides.
But adjuvants have not been previously approved for use with influenza vaccines in Canada, so it would require a more stringent review compared to a regular vaccine.
The United States and some European countries are not using adjuvants, which means they can fast-track the licensing of the vaccine for use in high-risk groups. Canada has chosen the slower path, the CMAJ editorial said.
Health Canada dismissed the editorial Monday. Canada's vaccine regulator, a branch of Health Canada, would quickly approve an adjuvant or non-adjuvant vaccine when one becomes available, and public health could use both types of vaccine, Health Canada said.
“Contrary to the suggestion made in the CMAJ editorial, Canada has a highly flexible regulatory plan on pandemic vaccine approval that can be swiftly adjusted to meet public health needs,” a Health Canada spokesman said in an e-mail.
“Canada's Pandemic Influenza Plan incorporates a balance between the need for speed in getting a vaccine to Canadians with gathering as much information as we can on vaccine safety and effectiveness.”
Scott Halperin, director of the Canadian Centre for Vaccinology in Halifax, indicated that one of the reasons Canada went with an adjuvant strategy is because non-adjuvant vaccine didn't work as well in the clinical trials for the H5N1 avian flu strain.
Although it's unclear if a non-adjuvant vaccine will be provide enough immunity, there's some indication from a study in China that patients have a good response, Dr. Halperin said.
The CMAJ editorial called for health workers to have access to standard vaccines by early October, and to the adjuvant vaccine no later than mid-November, in order to protect the public for a resurgence of the virus this fall.
Canada is in the best position because of the efforts of David Butler-Jones, Canada's Chief Medical Officer of Health, and of hundreds of others, said Dr. Hébert.
“We actually have a vaccine. We have a manufacturing facility,” he said. “But we may be in the strange position of not having it available before others.”
