Flu viruses are categorized into four types: A, B, C and D. Types A and B are the most harmful to humans and cause seasonal flu epidemics; in the Northern Hemisphere, flu season typically occurs ...

In some cases, it can lead to death. Influenza A viruses cause seasonal flu epidemics almost every year in the United States. They can infect humans and animals. For more information and resources ...

open image in gallery Health officials are warning that this year’s intense flu season will continue to hang around for ‘several’ more weeks. There have already been 43 million illnesses ...