WASHINGTON -- Health and Human Services Secretary Kathleen Sebelius said Tuesday that a massive school closing wouldn't stop the spread of the swine flu virus, saying vaccinations must be the defense against a menace that one report said could infect up to half of the population. 

"What we know is that we have the virus right now traveling around the United States," Sebelius said in a nationally broadcast interview. "And having children in a learning situation is beneficial ... What we learned last spring is that shutting a school down sort of pre-emptively doesn't stop the virus from spreading." 

Sebelius appeared on NBC's "Today" show one day after a special presidential advisory panel presented a grim report to the Obama White House, saying among other things that a "plausible scenario" for the United States later this year is wide-scale infections, possibly 30,000 to 90,000 deaths, mostly among young children and young adults, and perhaps as many as 300,000 sick enough to require intensive care unit treatment at hospitals. 

Asked in the interview what people should do while awaiting the arrival of a vaccine, with first supplies likely by October but most not until the Thanksgiving season, Sebelius said: "I think it's important that people begin to anticipate that we will have a vaccine. We think it's likely that we're going to need two shots for the vaccine." 

She said people should plan ahead for this, particularly those with pre-existing medical conditions, pregnant women and health care industry workers. Sebelius said federal health authorities also are recommending that people should immediately get their regular "seasonal" flu vaccine to bolster their health for the scenario yet to play out later this year regarding the swine flu virus. 

"Seasonal flu vaccine is ready at the beginning of September," she said. "We want the population that is most at risk to begin their seasonal flu vaccine now." 

Sebelius said on MSNBC that the government has asked drug makers to accelerate the manufacture of antiviral medication that could be administered intravenously to hospitalized swine flu victims. 

A report by the President's Council of Advisors on Science and Technology, delivered Monday, said that while the impact of H1N1 was impossible to predict, a "plausible scenario" is that the epidemic could "produce infection of 30-50 percent of the U.S. population this fall and winter, with symptoms in approximately 20-40 percent of the population (60-120 million people), more than half of whom would seek medical attention." 

Swine flu could lead to as many as lead to as many as 1.8 million U.S. hospital admissions during the epidemic, with up to 300,000 patients requiring care in intensive care units. In fact, those very ill patients could occupy 50-100 percent of all ICU beds in affected regions of the country at the peak of the epidemic and place "enormous stress" on ICU units. 

Seasonal flue typically causes 30,000-40,000 annual deaths, mainly among people over 65.
People with certain pre-existing conditions, including pregnant women and patients with neurological disorders or respiratory impairment, diabetes, or severe obesity are at high risk, along with certain populations, such as Native Americans, the report said. 

The fall resurgence in swine flu could occur as early as September, with the beginning of the school term, and the peak infection may occur in mid-October. 

The report emphasized that this was a planning scenario, not a prediction. But, it added, "the scenario illustrates that an H1N1 resurgence could cause serious disruption of social and medical capacities in our country in the coming months."