- The flu virus can be transmitted before symptoms appear.
- The flu virus has evolved to infect more hosts.
- Flu symptoms increase a person's contagiousness.
- The peak of flu symptoms is when a person is most contagious.
- The flu virus has a strong drive to survive and infect more hosts.

- The flu virus can be spread even before symptoms appear.
- The flu virus is clever and has adapted to infect more hosts.
- Symptoms of the flu make a person more contagious.
- The peak of flu symptoms is when a person is most contagious.
- The flu virus has a drive to stay alive and infect more hosts.

Cold & Flu: When Are You Most Contagious?