Antibodies in Llama Blood Might Eliminate the Need for Yearly Flu Shots

Getting your yearly flu shot is an important way to protect yourself against the latest strains of the virus. But the annual practice can also be annoying, as evidenced by the more than half of all Americans who skip it. Now, BBC reports that scientists may have discovered the key to a perennial preventative flu treatment hiding in an unlikely source: llama blood.

According to a new paper published in the journal Science, the tiny antibodies produced by llamas are better equipped to fight the influenza virus than the larger ones found in humans. When the flu virus enters your body, specialized white blood cells called B lymphocytes make antibodies to attack it; they glob onto proteins on the outside of the virus, marking it so the immune system knows what to eradicate. But this only works if the shape of the antibody fits the proteins on the outside of the virus. If the exterior of the flu virus has mutated since your last flu shot, your body may not be able to recognize and stop it.

Llama antibodies work a bit differently. They're much smaller than humans', which means they can reach the core of an influenza virus—a.k.a. the part that looks the same from strain to strain. If scientists can make a human antibody that functions the same way, they will essentially develop a one-size-fits-all treatment that could continue to be effective as years progress.

For their study, researchers from the Scripps Institute in California made a synthetic antibody that borrowed elements from some of the strongest flu antibodies produced in llama blood. After wrapping the antibodies' genetic information in a harmless virus and infecting flu-sickened mice with it, the flu virus was stopped in almost every case. Only one of the 60 flu strains that were tested persisted, and it was one that doesn't infect humans.

This flu "vaccine" isn't really a vaccine at all—it's more like gene therapy. Unlike current flu shots, it doesn't have to train the body's immune system to be effective, which would make it an especially appealing option for people with weakened immune systems like elderly patients. But human trials still need to be completed before the promise of a stronger, longer-lasting flu treatment becomes a possibility.