New protein may protect against many strains of flu

There’s a new weapon in the fight against the flu: Researchers have discovered that a synthetic protein called EP67, commonly used as a helper molecule in vaccines, is highly effective on its own when taken within 24 hours of infection.

Vaccines are currently the best weapon we have against the flu. But vaccines target individual strains of the virus, meaning that if public health experts guess incorrectly when they develop that season’s flu shot, it will do little good for the population.

The new approach fights off infection by awakening and amplifying the immune system itself, so it is not subject to the same limitations.

The researchers, at San Diego State University and the University of Nebraska Medical Center, infected mice with the flu and then had the animals inhale a dose of EP67 within 24 hours. While mice that did not receive the protein lost 20% of their body weight — considered a sure sign of being sick — the mice given EP67 lost only about 6% of their body weight, and some lost none. When the researchers infected the mice with what should have been a lethal dose of the flu, all of the EP67 mice survived and all of the untreated mice succumbed.

Further analysis showed that a mouse’s response to EP67 resembles an amped-up, rapid-response version of the innate immune response to the flu, leading to the production of antiviral cytokines — molecules central to fighting viral infection — and an influx of several types of immune cells into the lungs. These two factors combined to shut down the flu before it could take hold, according to the study.

The research thus far has been carried out only in mice, and only with one strain of the flu. However, the scientists said they expect the approach could be useful against viral, bacterial and fungal diseases, and they believe it can be generalized to humans and other nonhuman species alike.