One Vaccine Dose to Fight Swine Flu

Fighting the swine flu may have gotten more manageable.

Australian and U.S. researchers said Thursday that one dose of the new swine flu vaccine looks strong enough to protect adults — and can begin protection within 10 days of the shot.

Australian drug maker CSL Ltd. published results of a study that found 75 percent to 96 percent of vaccinated people should be protected with a single dose — the same degree of effectiveness as the regular winter flu shot. That's remarkable considering scientists thought it would take two doses.

U.S. data to be released Friday confirm those findings and show the protection starts rapidly, Dr. Anthony Fauci of the National Institutes of Health told The Associated Press.

"This is quite good news," Fauci said.

The dose question has an important ramification: It means people will have to line up for influenza vaccinations twice this year instead of three times — once for the regular winter flu shot and a second time to be inoculated against swine flu, what doctors call the 2009 H1N1 strain, the Associated Press reports.

In the meantime, the first convincing trial results from a single 15-microgram dose in adults were published online Thursday afternoon by The New England Journal of Medicine. That trial was done in Australia, but the vaccine maker, CSL Limited, is under contract to supply millions of doses to the United States government, and the president of the company’s American subsidiary said he expected its trials here to have similar results.

The H1N1 swine flu pandemic has now reached 168 countries. It arrived in the United States late in the spring and infected more than one million people. It did not fade out as seasonal flu does, but persisted, especially in summer camps. Nearly 600 people had died by the end of August, according to the disease control agency.

Cases are now surging again, especially in the Southeast where many schools and universities reopen earlier than in the rest of the country.

Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, said trials now under way under the sponsorship of the National Institutes of Health were showing that adults who got only a single dose were protected within 8 to 10 days, which he said “corroborates and confirms the exciting data” reported in the Australian study, the New York Times reports.

U.S. public health officials have said they expect to distribute about 40 million doses of swine flu vaccine by mid-October, with a further 25 million doses available every week after that through the end of the year.

Because the two doses would have to be given at least three weeks apart, public health experts had said it would probably be Thanksgiving before large groups of Americans were protected from swine flu, a strain of influenza Type A, subtype H1N1. But if the vaccine is effective after just one dose, there will be more to go around and people will see immunity much sooner, San Francisco Chronicle reports.