The U.S. federal government will spend $884 million to buy more ingredients to make an H1N1 swine flu vaccine, the Health and Human Services department said on Monday.

Drug makers Sanofi Aventis, GlaxoSmithKline, Novartis and AstraZeneca unit MedImmune will get the money under existing contracts, HHS said in a statement.

HHS has already committed $649 million to buy vaccine made using the H1N1 swine flu virus, plus $283 million to buy adjuvants -- ingredients that help boost the immune system and make the vaccine work better.

The action we are taking today will provide flexibility in a future immunization program, if a program is recommended, HHS Secretary Kathleen Sebelius said in a statement.

The contract gives Sanofi $61.4 million for vaccine; Glaxo $71.4 million for its adjuvant; Novartis $346 million for vaccine and $343.8 million for adjuvant; and MedImmune $61 million for its nasal spray vaccine.

Earlier on Monday, the World Health Organization recommended that every country get vaccines against the H1N1 virus. The new strain of flu has caused the first pandemic of the 21st century, and has infected at least a million people and killed more than 400.

U.S. advisers are meeting later this month to decide about any vaccination campaign for Americans.

No vaccine could be prepared before October and companies have complained the virus they have been given to make vaccines with does not grow well in eggs -- meaning they might not be able to produce as much as they had hoped.

Last week, Sebelius said the U.S. federal government would pay for any H1N1 vaccine campaign but she said it was possible it would seek reimbursement from private insurers.

WHO said healthcare workers should get vaccinated first so they can take care of patients during the pandemic. Sebelius said it appeared that any vaccination campaign would focus on young adults and older children and people with underlying health conditions such as asthma and pregnancy, who are more likely to develop severe symptoms from influenza.

Normal seasonal influenza vaccination will also start as scheduled in the autumn and experts have already said the H1N1 vaccine would be offered separately from the seasonal immunization. Trials in human volunteers will start in August to ensure the new vaccine is safe and to determine what dose is needed.

If people need higher doses and two shots, then fewer people can receive the first batches of vaccine. The U.S. government is also stockpiling and distributing the antiviral drugs oseltamivir, sold by Roche AG under the brand name Tamiflu, and zanamivir, sold by Glaxo as Relenza, to treat people who become seriously ill.

(Reporting by Maggie Fox; Editing by Tim Dobbyn)

U.S. Medicine