Everyone 5 years and older is recommended to receive a primary series of a COVID-19 vaccine to be considered fully vaccinated.
For children 5 years through 17 years of age, a primary series consists of 2 doses of the Pfizer-BioNTech COVID-19 vaccine. For persons 18 and older, a primary series consists of:
A 2-dose series of an mRNA COVID-19 vaccine (Pfizer-BioNTech or Moderna), orA single-dose COVID-19 vaccine (Johnson & Johnson’s Janssen vaccine)
Pfizer-BioNTech or Moderna (COVID-19 mRNA vaccines) are preferred. You may get Johnson & Johnson’s Janssen COVID-19 vaccine in some situations.
Stay Up to Date with Your Vaccines
CDC recommends that people remain up to date with their vaccines, which includes additional doses for individuals who are immunocompromised or booster doses at regular time points. Individuals who are moderately or severely immunocompromised should get an additional primary shot and a booster shot.
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html?s_cid=11350:fully%20vaccinated%20cdc:sem.ga:p:RG:GM:gen:PTN:FY21
Get VaccinatedEveryone 5 years and older is recommended to receive a primary series of a COVID-19 vaccine to be considered fully vaccinated.
For children 5 years through 17 years of age, a primary series consists of 2 doses of the Pfizer-BioNTech COVID-19 vaccine. For persons 18 and older, a primary series consists of:
A 2-dose series of an mRNA COVID-19 vaccine (Pfizer-BioNTech or Moderna), or A single-dose COVID-19 vaccine (Johnson & Johnson’s Janssen vaccine)Pfizer-BioNTech or Moderna (COVID-19 mRNA vaccines) are preferred. You may get Johnson & Johnson’s Janssen COVID-19 vaccine in some situations.
Stay Up to Date with Your VaccinesCDC recommends that people remain up to date with their vaccines, which includes additional doses for individuals who are immunocompromised or booster doses at regular time points. Individuals who are moderately or severely immunocompromised should get an additional primary shot and a booster shot.
否则和整体数据不一致
数据？是那批人的数据很差吗？
https://www.straitstimes.com/singapore/health/booster-shot-must-be-taken-within-270-days-after-2nd-dose-to-remain-fully-vaccinated