What is the main challenge faced by biologists researching infectious diseases?

Well there alot of challenges faced by biologist researchers during the research of infectious disease, however major of those include the followings:
Defining and measuring the fitness for pathogens across the scales, developing models to capture the impact of co-infection on the evolutionary process, modeling how pathogen characteristics shape the evolution of hose immune diversity, understanding the maintenance of pathogen diversity, and developing the better models for the impact of genetic systems on pathogen evolution .

A lot of challenges u

Maybe meditation,stress relievers,try to have quite time try to get school done on time and try to go to bed earlier

Habit 1: be proactive  habit 2: begin with the end in mind  habit 3: put first things first  habit 4: think win-win  habit 5: seek first to understand, then to be understood  habit 6: synergize  habit 7: sharpen the saw