Swiss drugmaker Novartis joins two Chinese companies that say the vaccine can be produced in one dose.
In early results from human tests on one of its swine flu vaccine candidates, Novartis AG said one shot of its vaccine provided enough protection against the virus, as set out by criteria by U.S. and European drug regulators.
"The pilot results are encouraging," Andrin Oswald, CEO of Novartis Vaccines and Diagnostics, said in a statement. "This is important information for public health authorities who prepare for vaccination in the coming months with limited vaccine supply."
Most experts had thought two doses of vaccine would be necessary, since swine flu is a new virus to which virtually no one has immunity.
