Why Flu Virus Thrives in Winter

Cold Temperatures Pave the Way for Influenza Virus to Spread

Medically Reviewed by Louise Chang, MD on March 03, 2008

March 3, 2008 -- Scientists may have found a chink in the armor of the flu virus. Their discovery may lead to new flu treatments.

Researchers today reported that in winter, even the flu virus wears a coat, and it's a coat that helps the virus spread through the air. Tinkering with that coat might disarm the flu virus.

"Now that we understand how the flu virus protects itself so that it can spread form person to person, we can work on ways to interfere with that protective mechanism," Duane Alexander, MD, director of the National Institute on Child Health and Human Development, says in a news release.

Here's a quick look at the new findings on the influenza virus.

Scientists found that in cold temperatures, the flu virus forms a hard coating that acts like an envelope, helping the virus spread through cold air and then melting inside people to do its dirty work.

"Like an M&M in your mouth, the protective covering melts when it enters the respiratory tract," Joshua Zimmerberg, PhD, chief of the cellular and molecular biophysics lab at the National Institute of Child Health and Human Development (NICHD) says in a news release. "It's only in this liquid phase that the virus is capable of entering a cell to infect it."

In warmer temperatures, that coating doesn't form. So it's harder for the influenza virus to spread through warm air.

Zimmerberg and colleagues report their findings in today's advance online edition of Nature Chemical Biology.

Show Sources


Polozov, I. Nature Chemical Biology, March 2, 2008; advance online edition.

News release, National Institutes of Health.

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