New influenza shot can be 100% effective.

• Position: Vaccines

Flu is unpredictable. Influenza viruses are changing constantly--from one season to the next or even within the course of a flu season--making vaccine development difficult. Annual flu vaccines are designed to build immunity to the three most common strains of the virus predicted to be circulating that year. A study at the University of Georgia, Athens, suggests an improvement to the current model.

"Influenza viruses change their surface proteins for various reasons and by various means. As a result, we need annual vaccination to match the circulating strains," relates Biao He, professor of infectious diseases.

Current flu vaccines target surface proteins to develop resistance. He's vaccine targets an internal viral protein, called a nucleoprotein, which is critical for virus replication. Because it does not change as readily as the surface proteins, it is a great target for a vaccine.

Previous attempts to target nucleoprotein for protection were not effective. Using a vector process developed in He's lab that uses the common canine virus parainfluenza virus 5, or PIV5, his research showed for the first time that a single dose of immunization protected against H1N1 and H5N1, two different subtypes of influenza A virus. PIV5 is a virus that causes respiratory infection in dogs. Using PIV5 as a delivery mechanism to expose humans and other animals to antigens of important pathogens--influenza in this case--allows them to create vaccines that will protect against future infections in humans and animals.

"This finding suggests flu vaccines can protect against multiple strains, thus...