But why am I putting them in danger if they've had the vaccine?
Is it because it's not 100% effective or are you talking about people who can't have it?
I haven't seen the evidence about long term damage for people who are asymptomatic by the way - I'm not saying it doesn't exist, I've just not seen it. But I'd suggest that that can't be known by definition for a new virus because no-one has had it long term.
Yes, it is not 100% effective. Nothing is 100% effective, and even one that is 95% does NOT mean you are immune. If you are exposed to it constantly every day, eventually you're going to get it.
That's why it's important for even healthy people to get it, you can still pass it on even to those that have been vaccinated.
Basically... it's all about transmission rates. If the transmission rate on average is less than 1.0 it dies out, if it's greater it spreads. So if on average the disease spreads to even 1.1 people for everyone that catches it, it's going to spread. That's why you need in the upwards of 70% to 90% of the population to be vaccinated, to ensure that the spread gets under that 1.0 per person average. Otherwise it's just going to keep killing people.
The math isn't exact, a lot is guesswork, but we know for sure that you need a HIGH percentage to take it. So every single person that doesn't take it pushes us closer to the pandemic staying out of control.
As for damage to people who are asymptomatic, here are some articles.
"In 20% of the patients, Nagel found scarring, indicating irreversible damage to the heart muscle. Even young, healthy, asymptomatic athletes are showing heart damage that was detected by scans months later." -
https://www.biospace.com/article/sars-cov-2-causes-heart-damage-in-20-percent-of-people-with-mild-or-no-covid-19-symptoms/"A trauma surgeon on the front lines of COVID-19 is finding lungs infected with the virus are more damaged than a smoker’s lung. She said it’s true even for asymptomatic cases." -
https://www.cbs17.com/digital-stories/covid-19-infected-lungs-damaged-more-than-smokers-lung-doctor-says/