Transmissible infection catchup
There is currently a noticeable increase in hepatitis among children in UK and other areas. Significant percentage of them had had liver transplants (only done when needed in children). Reportedly, at least two of them had had contact, so the cause (unknown) is possibly contagious.
It's not the first instance of higher infection rates this year. One cause is lockdown measures, which kept people from being exposed to the regular number of things, so these things are now playing catchup, it has been said.
What is the effect of this in terms of how when less people are susceptible, an infectious disease travels less far whereas if less people are resistant the disease could travel further and faster? Is the net effect of the disease equal, greater or less?