BARCELONA, Spain (AP) - A Swiss drugmaker says one of its swine flu vaccines may work with just one dose, rather than two as previously expected.
That word from Novartis comes as China approved a swine flu vaccine which its producer, Sinovac, says will also work with just one dose.
Most experts had thought two doses of vaccine would be necessary, since swine flu is a new virus and virtually no one has immunity.
But in early results from human tests on one of its vaccine candidates, Novartis says one shot provided enough protection against the virus, although people who got two injections had a better immune response.
The World Health Organization isn't commenting specifically on Novartis' vaccine since it had not yet seen the data. But it says a number of companies are working on one-dose formulations which could theoretically increase the world's swine flu vaccine supplies.
(Copyright 2009 by The Associated Press. All Rights Reserved.)