Since no one answered this I will. If you're inoculated with the vaccine and it's a successful inoculation(94.5% of the time) the virus can't live in you. Your immune system recognizes it and kills it before it can replicate. You can't pass on a dead virus.
The Flu is one which has shown new strains or mutations quickly, which is why we have different Flu shots each year. Covid-19 hasn't shown this capability yet. It may have become easier to spread(not proven yet) meaning it can live longer outside a host but hasn't changed how it attacks the body. If it does mutate, it's not showing that it will mutate quickly and will take years. Thus the vaccine will still be viable for years.
Right now they're going to give people the freedom of choice on vaccinations. If they find enough people don't want to take it to reach that 80% herd immunity threshold, they'll start implementing that's it's required to work in Government offices or facilities, public schools, health care and such. Still don't reach that 80% they'll make it a requirement for all citizens just like the Polio vaccine. Somehow, someway, they'll reach that herd immunity numbers. They won't let misinformation from the gullible perpetuate a global pandemic.