False.
More people = bigger population.
Bigger population = easier spread of disease.
Easier spread of disease = increased rates of infectious disease.
Think of how infectious disease spreads rapidly in highly populated environments vs. lower populated environments. There's more people that touch the same door knobs you touch where a disease can lay and infect tons of people, there's more people to sneeze on you, there's more people to wipe their runny nose then shake your hand, there's more clothing to transfer disease, etc. More people will always result in increased rates of infectious disease, unless protections are in place for preventing disease spread, such as vaccinations of enough people to reach herd immunity in a given population.
Hope this helps!
