Two-step flu vaccine could protect against all strains

Researchers announced a new, two-step influenza vaccine this week that uses DNA to "prime" the body's immune system followed by a traditional seasonal flu vaccine that potentially protects the body against all strains of the influenza virus.

The new vaccine is currently being tested in humans by the National Institute of Allergy and Infectious Diseases, which told Reuters that tests conducted on mice, ferrets and monkeys suggest that the vaccine will be effective as a universal flu vaccine.

"This is the first step, conceptually, toward a good shot at a universal vaccine," NIAID Director Dr. Anthony Fauci told Reuters.

The new method uses a piece of DNA that is baed on the hemagglutinin protein, which is a mushroom-shaped structure on the virus, Dr. Gary Nobel told Reuters.

The body is then directed by the DNA to make antibodies against a part of the flu virus on the "stem" of the hemagglutinin protein that normally remains hidden. This part of the virus does not change form flu strain to flu strain, meaning that even as flu strains go throw constant change, this portion of the virus does not mutate.

As a result of the DNA method, vaccinated mice and ferrets were able to produce flu antibodies to protect them against flu strains from 1934 through 2007.

"We are excited by these results," Nabel told Reuters. "The prime-boost approach opens a new door to vaccinations for influenza that would be similar to vaccination against such diseases as hepatitis, where we vaccinate early in life and then boost immunity through occasional, additional inoculations in adulthood."

The vaccine also protected the animals against H5N1 bird flu, which some experts fear could mutate an cause a pandemic on a much larger scale than swine flu.