This means someone who had H1N1 in one flu season may still become infected with a different or sufficiently changed H1N1 virus later. Why Immunity After Infection Does Not Last Forever? The immune ...

"Bourbon tick" isn't a joke, as seen in the latest diagnosed case in Long Island, New York. Bourbon virus is a rare tickborne disease linked to severe illness and growing concern among researchers.

Viral infection is the invasion of the body by a small agent known as a virus. Viruses replicate inside host cells and can produce toxins that cause disease. The immune system helps to destroy viruses ...