CHICAGO (Reuters) - Clinical trials for the new swine flu vaccine have turned up no red flags, U.S. health officials said on Friday.
First results from studies of the new vaccines in adults and the elderly will be available in mid-September, but so far, the only complaints seem to be a bit of local soreness and redness in the arm at the injection site, they said.
"There are no red flags regarding safety," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, one of the National Institutes of Health.
Fauci said no side effects were seen 10 to 14 days after the first studies in adults, giving officials the confidence to start trials of the vaccines in children this week.
Two trials are under way in adults for the safety and effectiveness of two doses of the vaccine. The trials, which are also looking at whether one or two vaccinations will be needed, are nearly fully enrolled.
"We expect first dose data somewhere around mid-September if all goes well, and second dose data by mid-October," Fauci said in a telephone news briefing.
Fauci said studies in pregnant women should begin in September, as will studies using an immune system booster called an adjuvant. In all, the vaccines will be tested on nearly 4,600 people.
The U.S. Centers for Disease Control and Prevention said swine flu is still spreading widely across the United States, with 75 percent of serious cases and 60 percent of deaths among people under the age of 49. Alaska and Maine had "widespread" activity.
MORE THAN A MILLION CASES
CDC has confirmed 7,963 hospitalizations and 522 deaths from the pandemic H1N1 flu, said CDC's Dr. Jay Butler. He said there were likely more than a million actual cases, as most patients never get tested.
"It is important to remember that at this time of year we don't normally have influenza," Butler said.
He said the government expected to have 45 million to 52 million swine flu vaccine doses by mid October, when vaccination is expected to begin, and 195 million by the end of the year.
Fauci said even after people are vaccinated they should be aware they are not immediately protected -- the immune response from a vaccine takes about two weeks to develop.
Five companies are making both seasonal and H1N1 flu vaccines for the U.S. market -- AstraZeneca's MedImmune unit, CSL, GlaxoSmithKline Plc, Novartis AG and Sanofi-Aventis SA. Shares of all companies were up slightly in mid-afternoon trading on various exchanges.
Sanofi said on Friday it expects to deliver a bulk supply of H1N1 vaccine to the United States in October. The number of doses will depend on the vaccine's formula, which will be determined in October once clinical trial results are in.
Health officials said they expect an upsurge of flu cases in the autumn, as weather cools and students return to school. U.S. government officials have urged schools and businesses to encourage people to stay home when they are sick, to wash their hands frequently and keep workspaces clean.
"We can't stop the tide of flu any more than we can turn a hurricane in its course or stop the earth shaking during an earthquake, but we can mitigate the effects and help prevent people from becoming severely ill," Butler said.
(Editing by Phil Stewart)
(Additional reporting by Noelle Mennella in Paris)