Laura was infected with flu strain A last winter and was sick with flu symptoms for 10 days. This winter, Laura becomes infected with flu strain B. Predict what will happen to Laura during this infection. Laura's immune system will have to redevelop the antibodies for flu strain A before it can defeat the pathogen which means Laura will experience the feeling of being sick again.

This is a different strain of the flu virus meaning her B Cells have not previously made antibodies and she will become sick until her immune system can fight off the pathogen.

Laura's B Cells will remember the pathogen and will quickly release antibodies that allow her immune system to defeat the virus before she feels any symptoms of the flu.

There is only one strain of the flu virus so this scenario could not happen.