A particular antibody that, at least in mice, acts as a barrier to various forms of flu, some of which are lethal, was discovered by a group of researchers from various American institutes. This is an important discovery, especially in regards to the potential of a universal vaccine that can protect from all or most of the influenza virus strains, especially in a pandemic way.
Influenza viruses are a problem especially because new strains are born every year. This means that researchers have to design new vaccines every year, as explained by Ali Ellebedy, assistant professor of pathology and immunology at Washington University and one of the authors of the research that appeared in Science. Precisely for this reason, having a vaccine that protects against all the flu strains would be a historic result.
The researcher discovered a particular antibody two years ago, an immune protein in the blood of a patient admitted for influenza to the Barnes-Jewish Hospital in St. Louis. The blood sample he analyzed was unusual because it contained antibodies against hemagglutinin, the main protein found in the virus, but also other antibodies whose targets seemed unknown.
With the help of Florian Krammer, a professor of microbiology at the Icahn School of Medicine at Mount Sinai, Ellebedy discovered that at least one of the three mysterious antibodies blocked the activity of neuraminidase, another important protein underlying essential influenza viruses for her replication. To find out whether these antibodies could be used to treat influenza, the researchers then tested them on mice with lethal flu viruses. All three antibodies proved to be effective against different influenza strains and one of them, named 1G01, protected mice from all 12 flu strains tested.
“All mice survived, even though they received the antibody 72 hours after infection,” explains Ellebedy. “They certainly got sick and lost weight, but we saved them anyway. It was remarkable. It made us think that it could be possible to use this antibody in an intensive care setting when you have someone with flu and it’s too late to use Tamiflu.”
Now researchers are working intensively to develop new flu vaccines based on the 1G01 antibody, an alternative approach that could be very important for developing a truly universal vaccine.