Scientists make breakthrough in developing universal flu vaccine

A team of researchers took a substantial step toward developing a universal vaccine against different subtypes of influenza as animal trials showed promising results, according to the paper published Monday in the journal Nature Medicine.

Variation in viruses means that seasonal influenza vaccines need to be continually updated to protect against circulating strains of the infection. Seasonal vaccines also do not protect against unrelated subtypes that infect animals such as birds and pigs and can be transmitted to humans.

Researchers from the National Institute of Allergy and Infectious Diseases in the United States developed a nanoparticle vaccine targeting a particular part of the hemagglutinin (HA) glycoprotein on the surface of influenza viruses, the stem that is subject to minimal mutation.

The test on mice and ferrets showed that it could, to a degree, protect the animals infected with different subtypes of influenza virus, according to the study.

Researchers said they still need more work to determine if the vaccine work with other adjuvants -- especially those approved for use in humans -- and to unravel the mechanism by which these antibodies protect the host against influenza.