New study has found that the roof of a person’s mouth can play a key role in the spread of the Flu virus.

From MIT News:

Scientists have now discovered that the soft palate — the soft tissue at the back of the roof of the mouth — plays a key role in viruses’ ability to travel through the air from one person to another.

The findings, described in the Sept. 23 online edition of Nature, should help scientists better understand how the flu virus evolves airborne transmissibility and assist them in monitoring the emergence of strains with potential to cause global outbreaks.

Researchers from MIT and the National Institute of Allergy and Infectious Diseases (NIAID) made the surprising finding while examining the H1N1 flu strain, which caused a 2009 pandemic that killed more than 250,000 people.

MIT biological engineer Ram Sasisekharan, one of the study’s senior authors, has previously shown that airborne transmissibility depends on whether a virus’ hemagglutinin (HA) protein can bind to a specific type of receptor on the surface of human respiratory cells. Some flu viruses bind better to alpha 2-6 glycan receptors, which are found primarily in humans and other mammals, while other viruses are better adapted to alpha 2-3 glycan receptors, found predominantly in birds.

The researchers then examined tissue from different parts of the respiratory tract and found that viruses with the genetic reversion were most abundant in the soft palate. By three days after the initial infection, 90 percent of the viruses in this region had the reverted form of the virus. Other sites in the respiratory tract had a mix of the two types of virus.

The researchers are now trying to figure out how this reversion occurs, and why it happens in the soft palate.

The study opens up “a new frontier in our fight against future emergence of pandemic influenza viruses,” says Lin-Fa Wang, director of the program in emerging infectious disease at Duke-NUS Graduate Medical School.