Vaccines will in some cases prevent the catastrophic FALL_OUT of Covid. Assuming it works in the individual that is vaccinated, instead of a serious hospital stay, he may only get the sniffles for a few weeks. <that is just 1 possible outcome>
It's not like you buy a 1080TI, and it guarantees 600fps on Counterstrike. There are no such design guarantees to vaccines.
A vaccinated person is not free to do whatever he likes.
Why NOT ??
Vaccines aren't taken by everyone, denyers/antivaxx/lazy people/poor people without transportation. As much as 30% of americans may not get vaccinated.
Vaccines don't work 100% in all people. In some it takes, some it doesn't take.
Vaccine effectiveness is not 100%, typically 70% effectiveness in the field is quite high.
Effectiveness often DROPS after a few seasons if/when the virus mutates, which has a high probability due to the number of hosts it has already infected. <We don't know for sure, it's just likely, mutations with varying degrees of infectiousness have already been detected in the field>
Effectiveness could drop as low as 10-15%, as is the case with Flu vaccines. That's why they crank out new ones every year.
Given the current scope of the spread, ENDEMIC disease status is likely possible, there are 4 OTHER coronaviruses endemic to humans. A virus that has spread to the point where it will not simply go-away on its own. HIV for example is another endemic virus.
Covid19 causes long term, irreparable damage.
Covid19 can cause such damages IN seemingly asymptomatic victims.
Covid19 is not like a new sandwich anyone should try, Don't Try it.
EVEN WITH vaccines, social distancing guidelines should be followed for several years.
