Every member of the Yale community will, eventually, be able to receive the swine flu vaccine for free, Yale University Health Services Director Paul Genecin said.

Thursday, United States Secretary of Health and Human Services Kathleen Sebelius said the U.S. government has purchased 250 million doses of the vaccine — enough for everyone in America who wants it — and that it will be providing the vaccine to the states free of charge.

But while the quantity of vaccine the government purchased guarantees everyone in the United States will be able to receive it, it says nothing about when the vaccinations will be delivered and subsequently administered.

“We will have to do some rationing,” Genecin said. “Or to put it a nicer way, prioritizing, to make sure the people who need it are able to get it.” Since the vaccine is being shipped in waves as it is produced, there is expected to less than a sufficient initial supply, he said.

He explained that YUHS remains committed to vaccinating at-risk members of the Yale community first and that the generally healthy members of the Yale community will be vaccinated as YUHS’ supplies increase.

The first batch of vaccine is set to be distributed to the states the first week in October. The first batch will contain between 6 million and 7 million doses of vaccine, most of which will be in the form of a nasal spray, Sebelius said.

“[We] want to make it clear that the clinical tests have been very successful and [that we] have a high degree of confidence in its safety,” she said.

So far this semester, more than 300 Yale community members, most of whom are undergraduates, have contracted the H1N1 virus, Genecin said Thursday evening. For the past four days, YUHS has received notification of about 30 new cases per day — a slight uptick from the prior rate, he said. Genecin estimates that 40 percent of the Yale population will contract the illness.

The Connecticut Department of Public Health does not yet know how many doses of the vaccine it will be receiving the first week of October. Still, it is expecting to receive about 500,000 doses by mid-October, spokesman William Gerrish said. Because the disease’s prevalence varies across communities, state pubic health departments have been charged with distributing the vaccine, though the Centers for Disease Control and Prevention are providing technical support and guidance.

So far, 15,000 Connecticut health-care providers, including physicians, hospitals and long-term care facilities, have registered with CDPH to distribute the vaccine. The amount of vaccine YUHS receives come October will depend upon the amount the state Department of Public Health receives, Genecin said.

To date, the CDPH had not had yet decided how large an allotment of vaccine either Yale-New Haven Hospital or YUHS will initially receive or if other health-care providers in New Haven will be able to vaccinate members of the Yale community. “It’s really premature to say,” Gerrish said.

But there is good news: When the vaccine does become available, it will be highly effective, health officials said.

Anne Schuchat, the chief health officer of the CDC, said unlike the seasonal flu vaccine, which may or may not closely match the strain of flu prevalent in a particular year, the H1N1 vaccine perfectly matches the pervasive strain of H1N1.

Another key development concerning the H1N1 vaccine, she stressed, is that individuals over 10 years of age will only require one dose as opposed to the two doses health officials previously believed they would require.

Last week, the United States and eight other countries agreed to donate 10 percent of the vaccine they purchase to the World Health Organization for distribution to developing governments, Sebelius said, adding that she does not anticipate the pledged vaccine donation to cause a shortage in America.

“We think 250 million doses … will well be enough to not only make our donation [to the WHO], but make sure every American who wants to be vaccinated has that opportunity,” she said.

The CDC expects to distribute 40 million doses of vaccine by the middle of October and between 10 and 20 million doses every week after that.