These estimates which were given by the Centers for Disease Control and Prevention (CDC) predict that several hundred thousand would die due to the flu. These estimates are bound to add extra effort into getting a new vaccine ready for the fall flu season.
The health officials say that the flu will start spreading faster in the fall and when the schools open they would turn into germ factories.
The estimates which are based on the a flu pandemic from 1957, which killed nearly 70,000 in the United States dramatises the need for vaccines and other measures.
The World Health Organization (WHO) expected the first vaccines to be out by Sep or Oct 2009. And United States expects to begin testing on some volunteers in Aug 2009, with 160 million doses ready in October.
US has been one of the worst country hit by the Swine Flu with about 300 deaths and an estimated one million people have been affected.