"There are no red flags regarding safety," said Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases.
He added that results of clinical trials conducted on theses vaccines would be revealed around mid Sept.
Adults participating in the first five trials, which started on Aug 7 only complained of mild red swellings in the injected area. The vaccine was also tested upon children aged six months to 17 years.
From Sep 2009 it would be tried on 120 pregnant women, who are vulnerable to Influenza A (H1N1).
Jay Butler, heading the H1N1 Vaccine Task Force of the US Centers for Disease Control and Prevention (CDC) said that between 42 and 52 million doses of this vaccine would be available by mid Oct 2009.