The World Health Organization on Tuesday declared the H1N1 flu pandemic over, a little more than a year after a spring flood of cases prompted a global effort to curb its wildfire transmission.
“The new H1N1 virus has largely run its course,” Director-General Margaret Chan said.
That doesn’t mean that the so-called swine flu is gone. New Zealand is now grappling with local outbreaks. “Based on experience with past pandemics, we expect the H1N1 virus to take on the behavior of a seasonal influenza virus and continue to circulate for some years to come,” Chan said in a statement.
Evidence suggests H1N1 already is behaving more like other flu viruses. It is no longer the dominant virus but is spreading along with others. One key factor is that many people are immune because they’ve been infected. Many others have been vaccinated.
The declaration draws to a close one of the most tumultuous chapters in public-health history, beginning with the springtime outbreak of a disease that usually strikes in the fall and winter. The virus hopscotched across the country, taking its heaviest toll among healthy young adults, pregnant women, people with neuromuscular disorders and those with other medical problems, including obesity.
A rush to produce a vaccine stalled until manufacturers finished filling their orders for seasonal flu vaccine and overcame production problems. The first doses began trickling out in November, burdening health officials with tricky decisions about whom to vaccinate first. Vaccine is now abundant, and in April, the U.S. Centers for Disease Control and Prevention said H1N1 will be used in the mix of three viruses in the 2010-2011 flu vaccine.
Bill Hall of the Department of Health and Human Services said federal health officials are still urging people to get vaccinated. “H1N1 is still out there,” he said. “It can still affect people, especially young people and pregnant women.”