The difference is you can clearly do something about Covid and prevent all those deaths, where-as cancer and heart disease we still don't know how to prevent, and what we do know, we are similarly vocal and annoying about: lose weight, exercise, eat healthier, etc.

So it makes sense to mobilize in order to stop the spread of Covid and save all those people from dying from it.

On top of that, Covid has actually outpaced cancer and heart disease to become the number 1 cause of death (https://www.healthsystemtracker.org/brief/covid-19-is-the-nu...) in the US.

Another aspect is long Covid, where it could be 2 to 20 percent especially younger people, have long lasting symptoms. We don't know the real long term risks here. Not knowing is always scarier, people don't want to risk things. Heart Disease and Cancer to some extent are well understood.

Then you have to consider that the Covid death numbers are with all the measures that were put in place to stop it, and with a lot more people getting intensive care which would have died without. What's still unclear is what would death numbers look like if we'd done nothing to stop the spread and breached medical capacity.

Finally, I think Covid is scary, because as a virus it can mutate, and again, that fear kicks in, where you think it's only killing older people, but maybe at anytime there could be a variant that is more lethal and starts skewing things to younger people.

I don't think any of this is related to politics. It all just seems like expected reaction, a contagious disease that kills lots of people, but can be stopped if you could prevent its spread, which has unknown long term effects, and could possibly grow more lethal any day, and which will still screw you over for a few days even as a young lad. I think that's enough to explain the reaction the world over.