A universal flu vaccine may be within reach. Researchers from two independent studies reported Monday that creating a flu vaccine that may be able to target various strains of the flu virus without the need for continual reformulation is a real possibility, according to Wired.
A flu virus looks like a ball with many lollipops sticking out all around it. The lollipop-looking structure is a protein called hemagglutinin (HA). Seasonal flu vaccines work by targeting the head of the HA protein.
However, the head mutates rapidly to hide from antibodies. Thus, seasonal flu vaccines need to be reformulated again and again to make them more effective, which is why people get a flu shot every year. Unfortunately, flu vaccines are not always highly effective, like last year's vaccine that reduced an infected person's need to see a doctor by only 23 percent, Wired reports.
To create a more efficient flu vaccine, the first group of scientists began targeting not the HA's head, but its stem. Different strains of flu viruses have different HA heads, but they have similar HA stems. This means a flu vaccine that can effectively target the stem can work across various strains of the virus. Stems also mutate a lot less often than the head, removing the need for continual reformulation of the vaccine.
"This is very much a test of concept," lead researcher Barney Graham of the National Institutes of Health told the Guardian.
Graham and his team tested the vaccine on mice and ferrets. Their results showed that the mice were completely protected from H5N1 bird flu virus while the ferrets were partially protected.
The second group of scientists created a flu vaccine that targeted the head and manipulated the stem in such a way that it binds more effectively to antibodies. The research team, led by Antonietta Impagliazzo of the Crucell Vaccine Institute in Leiden, showed how mice injected by the new flu vaccine were protected from H5N1 bird flu and the H1N1 swine flu.
"This is really cutting-edge technology," Antonio Lanzavecchia, immunologist at the Swiss Federal Institute of Technology in Zurich and unaffiliated with the studies, told Science. "There is still work to do, but this is a clear step forward and it's headed in the right direction."
Hanneke Schuitemaker, who heads the viral vaccines discovery at Janssen Infectious Diseases and Vaccines, said the new flu vaccines are important in combating influenza.
"The results highlighted today shows there is potential in the development of a single universal vaccine to protect against all seasonal and pandemic influenza strains," she said, according to The Guardian.
The next step of research will be clinical trials testing the vaccines on humans, which can take a few years.
The study by Graham and his team was published in the Aug. 24 issue of Nature.
The study by Impagliazzo and her team was published in the Aug. 24 issue of Science.
