After months of infecting and killing thousands, it has all but disappeared. But not according to the World Health Organization.
The U.N. agency's emergency committee, a 15-member influenza expert panel, has determined that it's too premature to say the H1N1 pandemic virus is past its peak.
The panel deliberated for two hours on Tuesday and advised director-general Margaret Chan that while the virus is not circulating widely in many parts of the world, there's new transmission in West Africa and it's still unclear how the virus will spread when the southern hemisphere enters its winter months.
"Based on the evidence that was presented in that discussion and based on the subsequent discussions and the views of the emergency committee the director-general decided that it was appropriate not to make any changes in the current pandemic phases right now," Keiji Fukuda, the WHO's top influenza expert, told reporters in a briefing Wednesday.
If the WHO had declared the pandemic past its peak, it would have signalled to countries that they could prepare to transition out of pandemic mode. But they still had to remain vigilant.
The committee will review the status of the pandemic again in a few weeks to decide if the world has moved into the post-peak phase. But Dr. Fukuda noted that the virus is not as severe than previously believed.
"We don't really know what the final impact is and we won't know what it is until a year or two after the pandemic is over, but it appears to be on the less severe side of the spectrum of pandemics that we have seen in the 20th century," he said.
Canadian health officials have declared the second wave of the pandemic over for this country. The disappearance of H1N1 in Canada can be explained: Because about 45 per cent of Canadians have been vaccinated, and another 30 per cent were diagnosed with it and are thus immune, there are fewer people to infect, making its spread that much more difficult.
But the virus is still spreading in parts of Eastern Europe and Central Asia. The WHO said there's activity in African countries such as Senegal and Mauritania.
Canada, which in retrospect ordered too much vaccine, donated five million doses to the WHO to help the Geneva-based international body redistribute the vaccine to developing countries that couldn't afford their own supplies. Even after the donation, Canada is left with tens of millions of unclaimed doses. The federal government could choose to donate more down the line, or it can keep some of the remaining vaccine in reserve in case the virus returns. The vaccine has a shelf life of 18 months.