New Antibody Fights Several Flu Strains At Once

And could make the annual flu shot a thing of the past

Illustration showing an influenza virus attaching to a cell membrane via the surface protein, hemagglutinin

CSIRO via Wikimedia Commons

Researchers have recently discovered a unique antibody that can kill several different types of the flu virus, which could help them develop more powerful flu shots, according to a study published today in Nature Communications.

Each autumn, everyone from your mom to your physician tells you to get a flu shot. That's necessary because every season the flu virus mutates slightly and your immune system can't quite identify it, which means that the virus has more time to infect you and make you sick. Of the three types of viruses, Influenza A can cause the most severe symptoms and can infect several different species, meaning that the virus can "jump" from animals like pigs or birds to humans. Flu vaccines effectively give your immune system a "wanted" poster based on researchers' best predictions for the mutation that year. The goal is that, when the virus arrives, antibodies will be able to bind to the virus and kill it before it can infect you.

But this new antibody, called CT149, works differently. Normally, antibodies can only stop one virus strain from replicating by preventing it from infecting a normal cell. But CT149 binds to a different area of the cell membrane called the hemagglutinin stem region. This has the same effect--the virus is unable to bind properly to the host cell to infect it--but, unlike typical antibodies, can stop more than just one strain of flu virus.

The researchers gave the CT149 antibody to mice and found that it protected them from getting sick from four of the most powerful strains of the flu virus, including H1N1, the swine flu that reached pandemic infection levels in humans in 2009.

This work suggests that future flu vaccines could include this new kind of antibody that would be able to fight the most powerful types of influenza viruses and stave off several strains at once. That might make for stronger flu vaccines--and possibly reduce the shot's frequency to once every few years.