In general, the strength and duration of immunity that people get after they have had a disease varies much more than after vaccination, which is why getting vaccinated is generally safer and more effective than getting sick.
Vaccination may be offered regardless of a person’s history of symptomatic or asymptomatic SARS-CoV-2 infection (and whether the infection was before or after receiving the first dose).
Currently available data indicate that symptomatic reinfection within 6 months after an initial infection is rare. Thus, persons with PCR-confirmed SARS-CoV-2 infection in the preceding 6 months may delay vaccination until near the end of this period. When more data on duration of immunity after natural infection become available, the length of this time period may be revised.