The federal government has more than tripled its order of swine flu vaccines from the local biotech, said MedImmune. This added demand has taken the total purchases upto $453 million since May this year.

The Department of Health and Human Services has ordered 29 million doses of MedImmune's H1N1 flu vaccine in a $302 million contract. The Food and Drug Administration has recently given its approval to this vaccine for use in emergency cases from 2 to 49 years of age.

MedImmune has already got two previous contracts for the swine flu vaccine. The federal ordered a total of 13 million doses from the local biotech owned by the London- based AstraZeneca PLC.

MedImmune informed that it has already produced enough bulk vaccine to deliver those orders. It also said that it has a capacity to produce 200 mllion doses and the FDA has already begun releasing its first 3.4 million doses of its FluMist-based product.

Centers for Disease Control and Prevention officials have said that the distribution of the H1N1 vaccine should be exactly like the pediatrics vaccine, though it is the public health authorities who will determine who receives the doses.

The agency also informed that 90,000 provider sites might receive the swine flu vaccines depending on the requirement basis and then the shipping out of orders will begin in October.

The vaccine made by MedImmune uses live attenuated version of the now pandemic-status virus which is based on its seasonal FluMist intranasal spray form.

MedImmune is one of the four companies whose vaccine for swine flu has been approved by federal regulators.