This is a pretty succinct overview of what your options are if you live with people who had their empathy circuits fried by the pandemic and can't be bothered to care about disease transmission anymore.
Aside from masking: Setting up air filters is probably the lowest effort for biggest return on safety.
All these tips will help against actual regular colds and flus, too, since we are coming up on that time of year.
Also a reminder that it's never healthy to be infected by virus.
Everyone should read this article. I wish more people would understand this basic as hell fact.