Oct 2, 2008 (CIDRAP News) A top influenza expert with the World Health Organization today sought to allay fears that the upcoming flu season in the northern hemisphere will be unusually severe.
In a news teleconference, Keiji Fukuda, MD, MPH, coordinator of the WHO's global influenza program, said northern hemisphere locations are reporting only sporadic influenza cases. "There's no real indication on how this season is going to evolve yet," he said.
Fukuda said he's not sure why rumors are circulating that the northern hemisphere is in for a severe flu season. He said some people might be interpreting the presence of three new strains in the northern hemisphere's influenza vaccine as a sign that the season might be severe. However, he said, "Change itself does not mean that the season is going to be severe."
Recent reports in the British media described fears about the likely arrival of the Brisbane strain of influenza A/H3N2 in the United Kingdom during the upcoming season. That strain circulated at the end of Australia's 2007 flu season, then unexpectedly circulated in the United States during its 2007-08 season. The latest vaccine recommendations for both hemispheres include the Brisbane strain of H3N2.
The southern hemisphere's 2008 flu season has tailed off, and it appears that its vaccine was a good match with circulating influenza strains, Fukuda said. WHO officials are in frequent close contact with health authorities in Australia.
"The season in Australia was pretty mild," he said. "This is something that we can confirm."
Fukuda promised that WHO will monitor the season closely through its Global Influenza Surveillance Network, consisting of 122 labs that span 94 countries. The labs process thousands clinical specimens each year from patients who have seasonal influenza infections.
Apprehension in advance of the upcoming flu season is normal, but the best thing people can do is get their influenza vaccine, Fukuda said. "The key message is that this is the single most important thing you can do to protect yourself, the people around you, and the people you care most about," he said.
The best time to get immunized is before the season starts, which for people in the northern hemisphere is now, Fukuda said.
He said he worries that awareness regarding seasonal flu might be dropping off, because it seems to be overshadowed by H5N1 and pandemic flu concerns. "But this is the most common form of flu and the most preventable," he said, adding that the disease can affect people of any age or health status and spreads very easily. "If you breathe you are susceptible to getting influenza."
On Sep 22, the WHO issued its recommendation for the southern hemisphere's 2009 influenza season. It advised that the vaccine be based on the same three viral strains as this year's vaccine: for the A/H1N1 component, a strain similar to A/Brisbane/59/2007; for the A/H3N2 component, a strain similar to A/Brisbane/10/2007, and for the B component, a strain similar to B/Florida/4/2006. The recommendation also mirrors its guidance for the northern hemisphere's 2008-09 flu season.
Sep 23 CIDRAP News story "WHO keeps same strains for 2009 southern hemisphere flu vaccine"