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http://www.nytimes.com/2009/09/19/health/19flu.html

September 19, 2009

Vaccine for Swine Flu Is Ahead of Expectations

By DONALD G. McNEIL Jr.

More than three million doses of swine flu vaccine will be available by the first week of October, a little earlier than had been anticipated, federal health officials announced Friday.

But nearly all those 3.4 million doses will be of the FluMist nasal spray type, which is not recommended for pregnant women, people over 50 or those with asthma, heart disease or several other problems, officials from the Centers for Disease Control and Prevention warned.

Nonetheless, it will still be possible to vaccinate people in other high-risk groups: health care workers, people caring for infants and healthy young people.

The nasal spray contains a weakened live virus, while injections contain killed and fragmented virus. The spray gives a stronger immune reaction but carries a small risk that the virus will multiply too quickly in people with compromised immunity.

The normal side effects of FluMist include fever, headache, muscle aches, runny nose, vomiting and wheezing. These side effects, of course, mimic the flu, leading to the rumor that flu vaccines cause the illness. But health agencies say the side effects cannot expand into a life-threatening infection.

Swine flu cases are rapidly increasing across the country, the officials said. There is now “widespread” flu activity in 21 states, up from 11 a week ago, and virtually all the samples tested are the new swine flu.

“It’s a very strange thing for us to see that amount of influenza at this time of year,” said Dr. Daniel B. Jernigan, deputy director of the agency’s flu division.

Officials said they expected some confusion as a result of getting nasal spray out first. But they said they had decided it was better to move vaccine along as fast as possible rather than waiting until more injectable batches were ready, which could be in as little as a week or two later.

“The balance here is finding the sweet spot,” said Dr. Jay C. Butler, chief of the agency’s swine flu vaccine task force. “Do we hold it to build up stocks, or do we get small amounts out?”

Further confusion is expected because many Americans still do not understand the difference between the swine flu vaccine and the seasonal vaccine, of which 54 million doses have already been distributed.

Also, because the pork lobby has loudly objected to the term “swine flu,” all federal health officials are required to refer to it as pandemic H1N1 or 2009 H1N1. But seasonal flu shots also contain an H1N1 component; this means two H1N1 viruses could soon be circulating, each addressed by a different vaccine.

Swine flu vaccine will soon be streaming in batches from five manufacturers by overnight express to 90,000 distribution sites, some as small as a single doctor’s office and some as large as pharmacy warehouses. These sites will have to funnel their orders through state health departments, and from them to the C.D.C., which will coordinate the orders before passing them to the five companies.

Decisions about which groups should get which swine flu vaccine batches first “should be made locally,” Dr. Butler said, noting that an added complication was that no one yet knew how much demand there would be for all the 195 million doses the government had ordered.

“I think it was Yogi Berra who said, ‘It’s hard to make predictions, especially about the future,’ ” Dr. Butler said.

While flu cases are rapidly increasing, Dr. Jernigan said, cases serious enough to require hospitalization are now showing only some increase. “But,” he added, “it is not up at the same levels that we would see during seasonal flus.”

For that reason, Dr. Jernigan said, this wave of the swine flu has been acting more like a bad seasonal flu than the 1957 Asian flu, to which it is sometimes compared. That flu was blamed for the deaths of about 70,000 Americans, while a typical flu season is believed to kill about 36,000.