Surprise: get vaccinated. And now you'll say that "but you can get it even if you are vaccinated". Which is true, but of course less likely. How much less likely is known from the experiments.
Based on this study, vaccinated had a 25% chance vs 38% for unvaccinated to become infected if someone in their household had Covid. So a helpful reduction, but not night and day.
Once infected, from what I’ve read vaccinated folks are just as likely to spread it.