A compound in the mucus found on the oozy backs of a South Indian frog — known locally as a germ killer — can cause flu virus particles to explode. Researchers at Emory University have discovered that the compound, a peptide they've called urumin, is potent, yet precise, and capable of destroying an entire class of flu viruses while other cells and even other viruses emerge unscathed. Unlike other frog-based compounds, urumin is uniquely nontoxic, another unusual feature that makes it more promising from a therapeutic standpoint.
One of the greatest challenges researchers face when they fight the flu is the need to respond to shifting strains which are sometimes drug-resistant. New vaccines are made each year merely hoping to target the most common strains. Urumin may be the source for the next new anti-viral, and potentially the best one yet, for killing off flu virus.
In experiments, urumin was able to destroy flu in mice by targeting the lollypop-shaped protein (hemagglutinin (HA)) that sticks out of the surface of the virus particle. HA is like the glue that allows the virus to latch onto human cells and invade, so without HA, the flu can't survive. In the experiments, urumin targeted HA1 in particular, which is why it knocked out some strains of flu but not others. However, urumin also seemed to attack the HA stalks, which are home to the conserved regions that all HAs share. Therefore, if researchers could adjust the urumin's actions and create a vaccine that works on that stalk, they might be able to create a universal flu vaccine.
According to CDC estimates, the overall incidence of flu across all age groups during the 2014-2015 flu season was 40 million flu illnesses, 19 million flu-associated medical visits, and 970,000 flu-associated hospitalizations. There is no certain way to get an exact number of flu-associated deaths for a variety of reasons, but the CDC estimates that from the 2010-2011 flu season to the 2013-2014 flu season, deaths associated with flu in the U.S. ranged from a low of 12,000 (during 2011-2012) to a high of 56,000 (during 2012-2013). Furthermore, according to the CDC Foundation, the flu costs the U.S. more than $87 billion each year.
It's easy to see why the researchers will be following up on urumin; a universal flu vaccine would save tens of thousands of lives, improve millions of others, and save billions of dollars. And so, if this path does lead to a universal vaccine, we will owe it all to the mucus of the Hydrophylax bahuvistara, the antimicrobial frog.