* No evidence for raising pandemic alert to highest level
* WHO says drugmaker Roche stepping up Tamiflu production
* Agency has released some drug stockpiles to poor countries
GENEVA (Reuters) - No evidence has yet emerged that suggests the World Health Organization should raise its pandemic alert to the highest level due to a swine flu outbreak, a senior WHO official said on Thursday. Keiji Fukuda, acting WHO assistant director-general, told reporters that Switzerland’s Roche Holding AG has indicated it was stepping up production of its antiviral Tamiflu to deal with the infection.
Known generically as oseltamivir, the drug has proven effective against the new strain.
Fukuda said the United Nations agency has released some of its own Tamiflu stockpiles to the developing countries deemed most in need, including Mexico.
On Wednesday, the WHO raised its pandemic alert level to Phase 5, indicating a global outbreak was imminent. That is a notch below the agency’s highest alert level.
“Today that evidence holds steady,” Fukuda told reporters.
The new H1N1 strain first emerged in Mexico and has killed up to 176 people there, according to Mexican authorities.
WHO laboratories have so far identified a smaller number of infections in Mexico. Fukuda said the WHO has confirmed 97 cases in Mexico and seven deaths, and 236 total infections worldwide.
“The number of cases being reported in Mexico probably represents a lot of the work being done right now to go through the backlog of specimens,” he said, adding that several thousand samples were being analyzed.
Good disease surveillance was now required in countries in the southern hemisphere, which is coming into its winter season when seasonal influenza tends to peak, according to Fukuda.
“It is possible that we will see outbreaks of the H1N1 virus occurring more frequently in the southern hemisphere than in the northern hemisphere. This is something we have to be on the watchout very carefully for,” he said.
Vaccine makers are working to create a swine flu vaccine but it could take months to produce it in large quantities.
Drug companies have a combined production capacity of about 500 million vaccines a year against seasonal flu, but Fukuda said it was unclear how many could be made for the new strain.
But he noted there had been technological improvements that may help, including the use of adjuvant to stretch supplies.
Reporting by Jonathan Lynn and Laura MacInnis, Writing by Michael Kahn and Stephanie Nebehay, Editing by Robert Woodward