It's hard to believe that 12 months ago, not many of us had ever heard the terms "swine flu" "H1N1" or even "adjuvant." But in the last eight months, many Canadians learned more about influenza than they ever would have imagined, thanks to stern health official warnings and breathless media coverage.
So with the dreaded "second wave" now appearing over, was H1N1 a "dud" of a pandemic, as Dr. Richard Schabas, medical officer of health for Ontario's Hastings and Prince Edward Counties Health Unit, declared earlier this year?
Or did we escape a potential disaster, perhaps only because information campaigns and vaccine programs were so effective?
Dr. Donald Low, a microbiologist at Toronto's Mount Sinai Hospital, says to blow off H1N1 as a blip would be irresponsible.
"This was not a dud," he told CTV.ca by phone, noting that any form of flu can be a serious infection.
He estimates that about 60 to 70 per cent of Canadians who were infected with H1N1 got sick enough that they had to stay at home, feeling miserable. Many were hospitalized, pregnancies failed, and of course, many died or ended up on ICU ventilators. And all of this occurred within a second wave that lasted just a few weeks.
But Dr. Neil Rau is not convinced H1N1 was worth all the fuss it garnered, insisting the strain turned out not to be any worse a virus than seasonal flu.
"This was the mildest of mild pandemics," he told CTV.ca in an email interview. "It is surprising to still see this pandemic being labelled by the WHO as 'moderate' rather than 'mild' so many months after we first began to appreciate its severity."
Death rate no higher than seasonal flu
The official number of deaths H1N1 has caused worldwide since April, according to the World Health Organization, is slightly more than 10,000. But that is almost surely an under-representation of the actual numbers, as many deaths are never tested or recognized as influenza related, particularly in countries with scarce medical resources.
A British study estimated the pandemic killed about 26 out of every 100,000 people who became infected. And Dr. Marc Lipsitch of Harvard University told a meeting of flu experts held by the U.S. Institute of Medicine he thinks H1N1 had a death rate of between 0.007 per cent an 0.045 per cent.
In contrast, seasonal flu has a death rate of less than 0.1 per cent.
While much attention with this virus has focused on its unusual ability to infect children, who became infected at much higher rates than they normally do with season flu strains, in the end few children died of swine flu. It was those over 55 who had the highest mortality rates, even though they were least likely to become infected.
Canada was at the forefront of the initial research into swine flu right from the start. The Public Health Agency of Canada's National Microbiology Laboratory in Winnipeg was first to map the genetic code of the H1N1 virus in April, and officials then swiftly implemented their plan to develop a vaccine.
Rau says in retrospect, the July decision to manufacture enough vaccine for all Canadians was the correct one. But once it became clear that H1N1 was not causing severe disease in healthy people, he thinks the plan should have been scaled back, since the mass vaccination program was neither necessary nor cost-effective, he believes.
"A targeted vaccine program from the outset would have made more sense and might have been more successful," he said.
"The wrong people were encouraged to get the vaccine well before there was enough vaccine to fulfill demand for anyone and everyone."
Both Rau and Low agree -- and probably most Canadians would as well -- that the early distribution of the vaccine was a mess. Local public health units were ill-prepared to handle the demand, and every region had a different, confusing approach as to who should access the vaccine first.
Was Canada right to use a vaccine adjuvant?
While lessons will be learned in that regard, Dr. Low says one decision that PHAC officials made early on now seems to have been the right call: the decision to add an adjuvant with the vaccine.
The adjuvant boosted the vaccine's immune response and allowed manufacturers to use a smaller amount of "pure vaccine" in each dose at a time when manufacturers were having trouble producing large amounts of vaccine quickly.
"I think the right decision was made -- and it's being proven now -- to use an adjuvanted vaccine. That was the right way to go," Low says.
Low concedes it was a tough call, because an adjuvant in a flu vaccine was something Canada had never used before and there were widespread worries that the vaccine wouldn't be safe.
"But at the end of the day, when we look to our neighbours to the south, they're still trying to get out their vaccine -- and not very effectively, while we pretty well have finished," Low says.
But Rau isn't ready to say that the adjuvant decision was the right way to go.
He's not yet convinced that the adjuvant really improved immune responses compared with the non-adjuvanted vaccine. And he says the messaging about the unclear safety of the unadjuvanted vaccine only confused Canadians.
"The communications regarding the safety of adjuvants became a nightmare for PHAC, and created a perception of lesser safety for the adjuvanted form than the unadjuvanted form, especially when pregnant women were offered the latter," Rau says.
"The 'tried and true path' is likely the better path to take in the midst of an emergency situation."
What really bogged down the vaccine rollout was the decision to suddenly stop vaccine production to focus on non-adjuvanted vaccine. The timing of that move could not have been worse, coming as it did during the peak of the second wave.
"We had a good vaccine giving a good immune response and we got held up by a couple of weeks -- if not more -- because of that. We could have had the vaccine rolled out that much earlier," says Low.
Federal officials have reportedly learned from that mistake, with a source telling The Globe and Mail last month that when the time comes to renegotiate the pandemic vaccine contract, more than one manufacturer will be chosen.
What also needs to change in the future is Canada's pandemic plan, Rau believes. He says the plan was too focused on a worst-case scenario, so that when it emerged this pandemic was milder than planned for, there was no way to "dial it down."
"We should not be patting ourselves on the back for having grotesquely over-estimated the burden of a problem. Over-estimation of the problem was incredibly resource-intensive," says Rau.
"Too much planning is bad thing."
