The H1N1 swine flu pandemic has now officially ended, according to the World Health Organization (WHO), although many national health authorities saw a sharp drop in cases and began canceling vaccine orders months ago.
The world is moving into the "post-pandemic period" with global levels of H1N1 transmission now at an intensity similar to that of the seasonal flu, WHO's director-general, Dr. Margaret Chan, said this morning.
Many health authorities in the United States "and most people around the country" thought the pandemic had ended in the spring, with the close of flu season, Dr. William Schaffner, chairman of the Department of Preventive Medicine at Vanderbilt University in Nashville, Tenn., said.
The WHO announcement addressed worldwide levels, however, so the organization had to wait for the southern hemisphere to go through its flu season (during the U.S. summer) before hammering the final nail in the coffin of the H1N1 global pandemic, he added.
The H1N1 virus has abated but is not gone, Chan warned this morning. It will continue to circulate and cause illness and "continued vigilance is extremely important."
The WHO has recommended that health authorities continue to monitor severe cases of swine flu and unusual flu cases, and that high-risk individuals, such as pregnant women, the elderly and small children, continue to be vaccinated if vaccine is available to them.
Many swine flu experts agree with Chan's announcement, emphasizing that the end of the pandemic does not mean that the virus will disappear, only that it will be behaving more like the normal seasonal flu.
"With every pandemic … the bug settles in and becomes part of the annual cycle of influenza" once the pandemic is over," said Dr. Frank James, health officer for Washington's San Juan County.
Whereas the H1N1 strain "crowded out" other influenza strains last year, it is now expected to intermingle with a few other viruses for this flu season.
Many experts also urged Americans -- even those not in the high-risk groups -- to get vaccinated this flu season regardless of H1N1's decline.
"We should remember that [seasonal] flu causes 36,000 deaths on average each year," Vanderbilt's Schaffner said. "It remains a serious illness."
The Centers for Disease Control and Prevention endorses such caution, recommending that everyone 6 months and older be vaccinated against influenza.
"This is the first year for such a comprehensive recommendation from the CDC," Schaffner said, and this year's vaccine, which will include H1N1 and two other influenza viruses, will be available "in abundance" and provide "very broad protection."
But the CDC's broad recommendation has some experts questioning the necessity of such an extensive vaccine program.
"There's just no evidence that mass vaccination against flu works, but there is evidence, thanks to [the H1N1 epidemic], that mass vaccinations are an effective way of transferring public money to private hands," said Philip Alcabes, professor of Urban Public Heath at Hunter College's School of Health Sciences in New York City.
About $1.6 billion of taxpayers' money was given in 2009 to pharmaceutical companies and vaccine manufacturers "for a vaccine that most Americans didn't want to get," he said.