WASHINGTON (Reuters) - U.S. trials of Sanofi- Pasteur SA’s and CSL Ltd’s H1N1 swine flu vaccines confirm that only one dose is needed to protect people, U.S. health officials said on Friday.
“I am very pleased today to be able to tell you that the initial results from the NIH (National Institutes of Health) sponsored trial corroborate and reinforce the findings from the companies,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told a news conference.
Fauci said the immune response was quick, too. People appear to be protected eight to 10 days after being vaccinated.
“Americans who get their H1N1 vaccine will most likely be immunized and protected against the virus sooner than we thought,” Health and Human Services Secretary Kathleen Sebelius told the news conference.
Sebelius said U.S. officials had feared the most vulnerable Americans would not be fully immunized until November. “It shortens the window of worry and more people can be protected much earlier,” Sebelius said.
Fauci said the trials had shown very few side-effects and all so far were minor. CSL reported on Thursday that other trials showed just a single dose of vaccine was needed and, last week, Novartis AG and China’s Sinovac Biotech Ltd also said they could protect people with one dose of their vaccines.
The new H1N1 strain of flu, declared a pandemic in June, could eventually infect one third of the world’s population, or 2 billion people, according to the World Health Organization.
Because it is a new strain, infectious disease experts have said people would likely need two doses to get full immunity against the virus. They are rushing to put in place vaccine programs as the weather cools in the Northern Hemisphere and the traditional flu season starts.
The United States hopes to vaccinate 160 million Americans considered at highest risk of death or severe disease by the beginning of December. These include pregnant women, people with asthma, diabetes or heart disease and children and young adults.
The studies show that adults under age 65 will need only one dose, meaning supplies will cover more people. Studies in children and pregnant women are ongoing, but typically children who have never been immunized against flu need two doses to get full protection.
U.S. officials have said they expect to have 195 million doses of H1N1 vaccine and plan to distribute the H1N1 vaccine for free.
Dr. Jesse Goodman of the U.S. Food and Drug Administration said mid-October was still a realistic date for most U.S. vaccination to start.
“As it becomes ready we will try to make it available,” Goodman said.
Dr. Anne Schuchat of the U.S. Centers for Disease Control and Prevention said H1N1 flu was now active in all 50 U.S. states, mostly in children and young adults.
“The levels of flu activity that we are seeing now in September are extremely unusual for this time of year,” Schuchat said.
“It is a bit of a race to get the vaccine available and out there as quickly as possible ahead of the disease,” she said.
The officials urged Americans to get their seasonal flu vaccine, which is now being delivered to doctors’ offices. Schuchat said 38 million doses were available now and 115 million doses would eventually be rolled out.
Reporting by Maggie Fox; Editing by Andre Grenon, Toni Reinhold