Flu is taking off in the U.S., with 40 states reporting high or very high levels of flu-like illness last week.

The flu vaccine is a must for anyone over 60. Influenza can be more severe in older adults, often leading to complications like pneumonia. According to the Centers for Disease Control and Prevention ...

For example, if a human gets infected with a bird flu and also carries a human influenza A virus, these two viruses can ...