After vaccination your body will produce antibodies which protect you from getting COVID-19. In addition to those who are vaccinated, people who survived a case of COVID-19 may also have antibodies. However, we don't know how long antibodies against the coronavirus last. Also, current tests for antibodies are not necessarily reliable. Therefore, even if you had, or think you have had, COVID-19 already, you should still plan to get vaccinated.
Drafted 18 December 2020