Most H1N1 patients do not need drugs to recover: WHO

GENEVA (Reuters) - Most H1N1 flu patients do not require antiviral therapy to recover, but a vaccine for the strain is needed in case it becomes resistant to existing drugs, a World Health Organization expert said on Tuesday.

Nikki Shindo, a medical officer with the WHO's global flu program, told reporters about 10 percent of people known to have been infected with the strain known popularly as "swine flu" in Mexico and the United States required hospitalization -- far more than seen in seasonal flu.

"That I think has rightly urged the development and delivery of pandemic influenza vaccine," she told a news conference.

"We are also facing the risk of having resistant viruses," she said, noting that antiviral drugs like Tamiflu and Relenza have varying effectiveness against flus as they mutate.

"Given that we will have winter in southern American countries and also other parts of the southern hemisphere, there will be a risk of having viruses that will be highly resistant to antivirals," she said.

(Reporting by Laura MacInnis and Stephanie Nebehay)