ATLANTA - Health officials say the first doses of swine flu vaccine will be the nasal spray version.
The Centers for Disease Control and Prevention said Friday that about 3.4 million doses of nasal spray vaccine will be available the first week of October.
The government expects 195 million doses will be shipped out by the end of the year, most of them shots.
The nasal spray is approved for ages 2 to 49. Because it contains live flu virus, it's not recommended for some of the people at most risk from severe swine flu complications. That includes pregnant women, children younger than 2, and people with asthma and other chronic respiratory diseases.
Delivery of the spray will kick off the nation's complicated distribution of vaccine to protect against the novel H1N1 virus. Gradually increasing supplies of vaccine from five manufacturers are expected to be distributed at some 90,000 sites, said Dr. Jay Butler, who heads the CDC's H1N1 task force.
"Ultimately, anyone who wishes to be vaccinated should have the vaccine available to them," Butler said.
In the beginning, though, supplies are expected to be limited, even for high-risk groups targeted for early inoculation, including pregnant women, children from six months to age 24 and people with certain underlying health conditions.
State health departments will be in charge of requesting supplies of vaccine, and it will be up to them to decide whether to prioritize the very first doses even among the high-risk groups, Butler said.
Those orders will be transmitted to the CDC and then to the distributor, where they'll be filled within three business days then delivered by overnight service directly from the distributor to the provider. Distribution sites will be set up in four geographically diverse spots in the U.S., said Butler, who didn't know exactly where the sites would be located.
Eventually, 20 million doses a week
By the time vaccine production and delivery is in full swing, some 20 million doses a week will be available in the U.S.
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Early results of clinical trials of the vaccine show a robust reponse in adults, who likely will need only one 15-microgram dose of the vaccine to protect against H1N1. Children younger than 10 are likely to need two doses, similar to their response to regular seasonal flu, health experts said.
"There's every indication that we have a good match betwee the virus that causes illness and the vaccine we have to prevent it," Butler said.
Still, many more cases of H1N1 are expected before the vaccine becomes available. The virus has become the dominant strain of flu in a very early flu season, said Dr. Daniel Jernigan, the CDC's deputy director of influenza. The bug is spreading in all 50 states, with 21 states reporting widespread activity. Clinics are reporting twice the number of flu cases for this time of year, mostly in children and young adults.
"It's a very strange thing for us to see that amount of influenza at this time of year," Jernigan said.
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He emphasized the need for people to be vaccinated against seasonal influenza, which is also spreading. The H1N1 vaccine is not included in the seasonal shot, so people should plan on two separate doses for adults and likely three for children.
The government has ordered 195 million doses but may order more if there’s enough demand, health officials have said. Typically fewer than 100 million Americans get a flu vaccine every year, and it’s unclear whether swine flu will prompt much more demand.
A recent Associated Press-GfK poll found 57 percent of people said they were likely to get it.