Global health officials are scrambling to try to prevent the spread of the H1N1 swine flu virus, with U.S. officials moving Thursday with a recommendation that the Food and Drug Administration approve or license a vaccine.

In the U.K., the government launched a telephone hotline and Internet site as the number of new cases last week doubled to an estimated 100,000. The number of deaths attributed to the disease had held steady at 26 in England, not including cases diagnosed in Scotland, Wales and Northern Ireland.

Besides vaccine development, health officials are exploring other measures to protect those deemed most at risk of severe illness and death from the new virus, which though mild in most cases has proven deadly for hundreds of people world-wide.

For example, at a meeting in Cairo late Wednesday, Arab health ministers decided to ban children, the elderly and those with chronic illnesses from attending the annual Muslim pilgrimage to Saudi Arabia this year over fears the mass gathering could speed the spread of swine flu. The ministers stopped short of calling for the cancellation of this year’s hajj, which attracts about three million people every year to the holy cities of Mecca and Medina.

In the U.S., a federal advisory panel said the FDA should move ahead to approve or license the new H1N1 vaccine without waiting to receive data from clinical trials to test its safety and efficacy. The government and vaccine makers plan to start human studies of the H1N1 vaccine in the U.S. in the coming weeks, but the first-look data from those studies won’t be given to the FDA until September.

Each year the FDA approves seasonal vaccines based on strain changes without new human studies. The agency does test the vaccines for potency and also monitors vaccine safety on a continuous basis.

“I think this is an entirely appropriate way of proceeding and in the public health’s best interest considering that schools will be opening in a month,” said John Modlin, the panel chair and a professor of pediatrics at Dartmouth-Hitchcock Medical Center.

Health officials health officials said Thursday they have purchased enough bulk ingredients to produce 195 million doses of swine flu vaccine, and expect to make up to 100 million doses available in October, even though the vaccine is proving difficult to manufacture. Federal officials told the FDA panel Thursday that four companies making H1N1 vaccines — Sanofi Aventis, Novartis AG, GlaxoSmithKline PLC and CSL Ltd. — said the viruses used to make the active ingredient are producing yields of just 30% of what’s typically seen with seasonal vaccines.

The new H1N1 shots would be for a vaccination campaign that potentially would be targeted first at school-age children, who along with young adults have been hit hard by the new flu strain. A Centers for Disease Control and Prevention vaccine advisory panel will meet next week to make recommendations about such a vaccination campaign.

Anthony Fiore, of the CDC’s influenza division, said the agency is anticipating that two doses of an H1N1 vaccine would be needed. That limits the number of people at high risk for flu who would be able to get the shots in the early fall, although health officials are hoping that clinical study data will show that one dose is enough to protect some people. It will take until March to obtain enough doses for the entire U.S. population of just over 300 million people, officials predicted.

In the U.K., the national pandemic flu service will allow people who suspect they have been infected by the virus to be diagnosed and prescribed medicine by phone or online in an effort to ease the growing pressure of the outbreak on local doctors.

The U.K. government has said it has signed contracts to supply enough swine flu vaccines for the whole population. It expects to begin receiving supplies of the vaccine by the end of August and to have enough to treat 30 million people by the end of the year.