Pushing Americans to receive swine flu vaccinations, the Obama administration on Monday released a new slate of television and radio ads to counter an illness that already has infected millions.

The public service announcements target children and their parents, young adults and those in high-risk groups, such as people with asthma. The ads in English and Spanish come as a shortage of the vaccine is easing, with another 10 million doses expected to become available this week. The messages also are a shift from earlier efforts to teach Americans how to avoid spreading the illness, known also as H1N1.

Health and Human Services Secretary Kathleen Sebelius was announcing the new ads Monday.

"Getting vaccinated is the best way to protect yourself and your family against the H1N1 flu virus," Sebelius said. "Fighting the flu is a shared responsibility and it is up to all of us to help prevent the spread of the flu in your community."

The Centers for Disease Control and Prevention estimates that 22 million people have been infected with swine flu and 3,900 have died. Government tallies also include 98,000 swine flu-related hospitalizations.

The vaccine is becoming plentiful enough that some state and local governments are allowing everyone to get it, not just those in priority groups. There are 73 million doses available, roughly twice as many as there were a month ago, and another 10 million doses are expected this week, Dr. Thomas Frieden, the CDC's director, told reporters Friday.

Initially, limited supplies caused the CDC to advise state and local health officials to reserve doses for those at highest risk for severe complications from swine flu or those who take care of them.

Officials at the CDC said last week that it appears that a fall wave of swine flu infections has peaked. But flu is hard to predict, and health officials say they are worried of the possibility of a third wave this winter.

"Right now, Americans have a window of opportunity to get vaccinated," Sebelius said.

The new ad campaign features five television spots, including two targeting young Americans who are especially susceptible to the flu. Another three radio ads are available.