President Obama said Tuesday the H1N1 vaccine will be voluntary, but he "strongly recommended" that Americans get one.
Mr. Obama made his public plea in a Rose Garden press conference after meeting with administration officials preparing for the re-emergence of the new H1N1 flu as students return to schools and workers end their summer vacations.
"As I said when we saw the first cases in in the spring, I don't want anybody to be alarmed, but I do want everyone to be prepared," said Mr. Obama, flanked by Health and Human Services Secretary Kathleen Sebelius and Homeland Security Secretary Janet Napolitano. "We know that we usually get a second, larger wave of these flu viruses in the fall, and so response plans have been put in place across all levels of government."
H1N1 first was discovered in Mexico, then quickly spread into the United States and elsewhere around the world.
The number of people in the United States who have died so far from H1N1, or swine flu, is 556, according to the Centers for Disease Control and Prevention.
The World Health Organization reports 1,799 deaths worldwide.
A White House report suggests a worst-case scenario of 50 percent of the U.S. population becoming infected.
The first batches of a vaccine are expected to available by October.
Mr. Obama's speech included no new information and largely served to assure Americans that the government is ready and that they should take such common-sense prevention steps as coughing into one's sleeve.
The president outlined what he called the "four pillars" of the federal government's preparedness and response plan: surveillance, mitigation, vaccine and communications.
They include working with Congress, state and local officials; issuing guidance for schools, businesses and families; and recommending the flu shot.