Only Text Quote
When you get sick with the flu you get infected with flu viruses and they make lots of new flu viruses, but those new viruses are not exact copies of the old ones. They have mutations in them. A lot of those mutations are harmful.
When you get sick with the flu you get infected with flu viruses and they make lots of new flu viruses, but those new viruses are not exact copies of the old ones. They have mutations in them. A lot of those mutations are harmful.
