The Basics

• Research by the National Institute of Human Development has shown that flu viruses can have a strong layer of coating around them that is affected by body conditions at specific times of the year.
  
  

Summer

• The Influenza virus can enter a person's body at any time of the year. During the warm summer months the coating will melt before affecting an individual.
  
  

Winter

• The coating on the flu virus particles grows stronger during the winter months, making it harder for the body to fight off. If a person is infected during the summer and the virus has not been disposed of by the time winter rolls around, this can cause it to grow to a full-fledged infection despite a long period of dormancy.
  
  

Transmission

• Research conducted by the National Institute of Human Development has shown that the influenza virus is more easily transmitted during the summer months than winter months.
  
  

Considerations

• While the virus is weaker during summer months due to humidity in the air, it is possible for a person to become infected and show no symptoms for a long period of time. This is an essential period of dormancy. The virus can then grow strong during the winter and cause a person to get sick as the air gets colder.