From Mexico to China, people around the world have worn face masks to protect against swine flu, also known as the H1N1 virus. The problem? Experts could never say for sure whether such masks ...

It is caused by the virus types Flu A and Flu B. Flu A also has two subtypes ... So when you’re out in the public, you can protect yourself by wearing a mask,” said Estep.

And while no one can say with any certainty that numerous rallies, speeches, parades, and marches greatly exacerbated the spread of the flu, such undertakings are exactly the types of activities a ...