The politics of the pandemic complicate the conclusions of researchers.
From my experience, the most determing factor for germophobia is what i call "i know a bit of science". Also generally germophobia blooms more where there is no personal experience with infection. Yet we cannot deny that medical system loves to make hysterical statements about infections which makes people also hysterical.
I've found that most people, particularly germophobes, don't realise just how hard it is to actually engage in risky enough behaviours to make yourself sick enough to warrant hospital, let alone actually die! Not only are you fighting your own innate self preservation mechanisms, but your own various biomes are trying to preserve their ecosystems as well.
Thankfully, it's ridiculously hard even in 3rd world countries, let alone westernised countries, otherwise the bodies wpuld be piled mile high. Its ridiculous how little people critically think about things.
i like to think that i cohabitate peacefully with a lot of germs.
as long as they do not bother me, i do not bother them.
What is known is that where sickliness is increased (parasite load, pathogen exposure, etc) there is a simultaneous increase of social conservatism and right-wing authoritarianism. And we know that just by giving people vaccines or having them wash their hands decreases xenophobic responses. This isn't exactly brain science.