Determining primary series completion
People vaccinated outside of the United States completed the primary series if they:
*CDC does not recommend mixing different COVID-19 vaccines for the primary series but is aware that this is increasingly common in many countries outside of the United States. Therefore, for the interpretation of vaccination records, people who received a mixed primary series have completed the primary series.
If you didn’t complete the primary series
People vaccinated outside of the United States who have not completed the primary series as described above do not have to start the primary series over. They should get one primary series dose of an mRNA COVID-19 vaccine (Pfizer-BioNTech or Moderna). If the first dose was an mRNA COVID-19 vaccine, it would be best to get the same vaccine again to complete the primary series. They should also receive a booster when eligible.
If you completed the primary series
People vaccinated outside of the United States who completed the primary series should receive a booster when eligible.
Boosters for People Vaccinated Outside the United States
People who were vaccinated outside the United States—and who completed the primary series as described above and have not yet received a booster—should receive a booster of an mRNA COVID-19 vaccine (Pfizer-BioNTech or Moderna) at least 5 months after their last dose of a COVID-19 vaccine.
For People Who are Moderately or Severely Immunocompromised
People who are moderately or severely immunocompromised and received COVID-19 vaccines not available in the United States should either complete or restart the recommended COVID-19 vaccine series. This includes getting a booster when eligible in the United States. If they received booster dose(s) outside of the country with a vaccine listed for emergency use by WHO, they do not need to either complete or restart their COVID-19 vaccinations.
For more information, talk to your healthcare provider or see the COVID-19 Interim Clinical Considerations.
