A team of researchers has made a breakthrough in finding an antibody that protects mice against a wide range of potentially lethal influenza viruses, which could lead to developing a universal vaccine to treat or protect people against all strains of the virus.
The study was done by Scripps Research along with Washington University School of Medicine in St. Louis and Icahn School of Medicine at Mount Sinai in New York.
The antibody relates to a protein called neuraminidase, which is essential for the flu virus to replicate in the body. The protein, located on the surface of the virus, enables infected host cells to release the virus so it can spread to other cells.
Tamiflu, the most widely used drug for severe flu infection, works by inactivating neuraminidase. However, many forms of neuraminidase exist, depending on the flu strain, and such drugs aren’t always effective — particularly as resistance to the drugs is developing.
“There are many strains of influenza virus that circulate so every year we have to design and produce a new vaccine to match the most common strains of that year,” says co-senior author Ali Ellebedy, PhD, an assistant professor of pathology and immunology at Washington University. “Now imagine if we could have one vaccine that protected against all influenza strains, including human, swine and other highly lethal avian influenza viruses. This antibody could be the key to design of a truly universal vaccine.”
Ellebedy discovered the antibody — an immune molecule that recognizes and attaches to a foreign molecule — in blood taken from a patient hospitalized with flu at Barnes-Jewish Hospital in St. Louis in the winter of 2017.
To find out whether the antibodies could be used to treat severe cases of flu, it was tested in mice that were given a lethal dose of influenza virus. All three antibodies were effective against many strains, and one antibody, called “1G01,” protected against all 12 strains tested, which included all three groups of human flu virus as well as avian and other nonhuman strains.