One jab to rule them all: Scientists say universal flu vaccine is a step closer

A universal flu vaccine that protects against multiple strains of the virus is a step closer after scientists created experimental jabs that work in animals.

The vaccines described in studies this week prevented deaths or reduced symptoms in mice, ferrets and monkeys infected with different types of flu, raising hopes for a reliable alternative to the seasonal vaccine.

Doctors hope that a universal flu vaccine would do away with the need for people at risk to have flu jabs every year, and even protect the public from dangerous, potentially pandemic, strains that jump from birds or pigs into humans.

Conventional flu vaccines target the “head” of a molecule called haemagglutinin (HA) that sits on the surface of flu viruses. But because the head of the HA mutates so rapidly, seasonal flu vaccines must be continually re-formulated to ensure they are effective.

During the last flu season, mutations in the HA molecule on one of the most common circulating strains, H3N2, meant that the seasonal flu vaccine offered little protection . Public Health England said in February that the less effective vaccine was likely to have been behind a steep rise in flu deaths.

In two studies reported on Monday, separate research teams describe how they created novel flu vaccines that target the “stem” of the HA molecule instead of the head. The stem of the HA molecule is similar across different flu strains and mutates far less often.

One of the teams, led by Barney Graham at the National Institutes of Health in Maryland, created their vaccine by attaching part of a flu virus’ HA stem to tiny balls of protein. These protein nanoparticles kept the stem intact and made it easy for the immune system to spot once it was injected.