The widely divergent approaches taken by Canada and the United States on the H1N1 pandemic strategy and vaccine rollout are part of an enormous public-health experiment whose outcome is impossible to predict.
The United States has opted for unadjuvanted vaccines while the bulk of H1N1 vaccine distributed in Canada will contain immune-boosting adjuvants. South of the border, health officials are already dealing with a vaccine shortage as Canada prepares to begin inoculating the public. U.S. President Barack Obama has declared the virus a national emergency, while Prime Minister Stephen Harper has so far remained near the sidelines to allow public-health officials to advise citizens.
As the H1N1 virus becomes more widespread across North America, the differing national strategies are sparking debate and raising ethical questions about which country is taking the correct approach. It may be tempting to point fingers at this early stage, but health experts and government officials say it will be too early to draw any conclusions until well after the pandemic is over.
The Globe on H1N1
|
Vaccination strategy
U.S. officials opted for an H1N1 vaccine made without adjuvants, which is now a household term across Canada. Adjuvants are substances that help boost the immune response of individuals receiving the vaccine. But the adjuvant being used in the H1N1 vaccine has not been approved by health officials in the United States, so it is not being added to the vaccine there.
There have been concerns that vaccines containing an adjuvant could cause Gulf War syndrome, a mysterious illness suffered by many Persian Gulf war veterans, typified by symptoms such as fatigue and loss of muscle control. But there is no scientific evidence to support that theory.
Some previous studies, involving rodents, have suggested that certain adjuvants may cause autoimmune disorders. However, health officials say the specific adjuvant being added to the H1N1 vaccine now being distributed across Canada has been used in Europe for many years, tested on tens of thousands of people and been found to be safe.
Although any vaccine comes with risks, they are “infinitesimally small” while the risks from influenza are “far, far higher,” said Anand Kumar, a specialist in critically ill patients with the Winnipeg Regional Health Authority and an associate professor of critical care and infectious disease at the University of Manitoba.
“The risk-benefit here is so incredibly in favour of getting vaccinated it's not even worth considering adjuvant or no adjuvant,” Dr. Kumar said in an interview yesterday.
Vaccine supply
But adjuvants do not just boost the immune response. They also allow vaccine makers to use less antigen, the active ingredient in vaccines, meaning that they can produce significantly more vaccine – four to five times more – than would be possible without adjuvants. It's a critical point because it allows makers to produce large amounts of vaccine quickly as the virus spreads throughout a country. The necessity of being able to produce significant quantities of vaccine rapidly hit home this week as reports of major shortfalls in the United States began to emerge.
U.S. officials had said 40 million doses would be available by the end of October, but this week, less than 23 million were ready. The shortage is due primarily to manufacturer difficulty in producing the vaccine.
