September 2010

Closing In on a Universal Flu Vaccine

Scientists developed a way to generate antibodies that attack many strains of influenza viruses in animals. The success moves researchers a step closer to a universal flu vaccine—one that protects against multiple viral strains for several years.

Each year influenza, or flu, kills about 36,000 people nationwide. Researchers need to reformulate the vaccine each flu season because the viruses continuously change. A universal flu vaccine would block many viral strains for years and greatly control the spread of influenza.

NIH researchers were able to develop a vaccine that protects against multiple strains of the flu subtype called H1N1. The vaccine includes a piece of DNA that makes a specific viral protein. They vaccinated mice, ferrets and monkeys. Some of the animals later received a booster shot of a seasonal flu vaccine.

Animals given both the DNA and the boost vaccines produced antibodies that blocked several H1N1 strains. The antibodies also blocked other flu subtypes, including H5N1.

The scientists next tested to see if the vaccine could protect animals from infection. After getting the boost, 20 mice were exposed to the deadly 1934 flu virus, and 80% survived. Mice receiving DNA only or seasonal flu vaccine only all died. Ferrets who got the DNA-boost vaccine were also protected from infection.

“This significant advance lays the groundwork for the development of a vaccine to provide long-lasting protection against any strain of influenza,” says Dr. Anthony S. Fauci, director of NIH’s National Institute of Allergy and Infectious Diseases.