U.S. Health and Human Services Secretary Kathleen Sebelius says the United States expects to receive the first round of swine flu shots sooner than expected.
Sebelius said on ABC's This Week Sunday that some of the vaccine will be available as early as the first week of October.
She said the earliest doses will be used for health care workers and other high-priority groups.
Researchers discovered last week in clinical trials that the new H1N1 swine influenza vaccine could protect against the virus with just one dose instead of two as had previously been expected.
This means vaccine supplies could be available for twice as many people.
They also said trials showed that adults who got a single dose of the swine flu vaccine were protected from the virus within eight to 10 days.
Earlier this month, the International Federation of Red Cross and Red Crescent Societies said people in developing countries are most vulnerable to the H1N1 swine flu virus.
The organization said that not only are people in developing countries most vulnerable, but they are also less likely to have access to life-saving information.
The World Health Organization has declared the swine flu outbreak a pandemic, and says up to two billion people may eventually be infected. It says more than 3,000 deaths related to the virus have been reported worldwide.
Some information for this report provided by AFP and AP