What is a strain?

Question

I was reading about different virus. What is a strain?

Answer 1

A strain is when you can look it up in the dictionary for yourself, but don't.

So you ask so Innocent a question that your stupidity out shines any essence of intelligence lurking between your ears. .

Answer 2

A virus can exist in different forms. A strain is the same but a little different. Think of it as a different breed but the same species.

Answer 3

A strain is a well-characterized isolate. It can be either genotypically or phenotypically different to existing strains. The flu virus changes so fast that every outbreak is caused by a different strain.