gut bacteria

Usually if you’ve been vaccinated, and regularly wash your hands, you are pretty safe from catching the flu. But, a new study has revealed that in fact all it takes to catch the flu is inhaling someone else’s infected breath. 

The recent study, published in Proceedings of the National Academy of Sciences was carried out by researchers at the University of Maryland in the U.S.They gathered 142 college students who were suffering with the flu and had them sit inside a specially designed machine from 30 minutes a day for three days. The machine, called the Gesunheit II collected samples of their breath as they coughed, sneezed, spoke, and just exhaled normally. By the end of the experiment, the volunteers had provided over 200 testable breathing samples, along with nose and throat swabs. 

How Close Have Scientists Come to Creating a Universal Flu Vaccine?

The results were as expected, with the researchers finding plenty of infectious viral particles in the samples taken from the volunteers. However, they did find infectious flu virus in eight of the 23 samples without any coughing. Almost equally as surprising, the few samples of people sneezing didn’t contain a greater presence of flue particles than other samples, suggesting that sneezes are both rare and not really all that important to airborne flu transmission. This study isn’t the first to highlight that normal breathing carries infectious flu, but it is the first to confirm it via these sorts of naturally obtained samples. 

“People with flue generate infectious aerosols (tiny droplets that stay suspended int he air for a long time) even when they are not coughing, and especially during the first days of illness,” explained senior author Donald Milton, a professor of environmental health at the University of Maryland’s School of Public Health. 

Not only this, but the study also revealed some other aspects of flu infection. The virus seems to make us sick in one of two independent ways. One is through irritating our upper respiratory tract, where the nose and throat reside; or by nesting deeper in the lower respiratory tract, where the lungs are. It appears the infectious particles generated by breathing happen only with lower respiratory infections.


What is interesting though, is that people who were recently vaccinated, either that current flu season or the last, seemed to be more likely to have a lower respiratory tract infections and to shed more of the virus while breathing or coughing. This is also something that’s never been noticed before, and what it could potentially mean will require a lot more research to work out, the authors explained. It is known that vaccination, even when it fails to prevent the flu, can reduce the severity of symptoms. 

It would seem folks that the only way to really avoid spreading the flue, whether it be at your job or school, is to stay at home and avoid contact with everyone.