I’m not too sure what you’re trying to say. You might want to work on improving your presentation skills.

However in the meantime, I would like to point out that all it takes for a viral disease to happen is for one single virus to get in the body. If that virus makes it to a cell in time and hijacks that cell’s internal machinery to make more viruses, you will now have the disease that particular virus creates.

I would also like to point out that the molecules on a virus’ protein coat need a very particular arrangement of molecules on a cell’s outer wall to key into. Which is why a virus may be harmless to a mosquito, but deadly to us. The virus can’t interact with mosquito cells but it can with ours.