The Center for COVID-19 Situation Administration (CCSA) has approved shortening the period of the third dose, or booster dose, to tackle the COVID-19 Omicron variant, which is spreading across the world. The formula for the third dose is as follows:
(1) Two doses of Sinovac or Sinopharm can be followed by AstraZeneca or Pfizer or Moderna, four weeks or more after the second dose;
(2) two doses of AstraZeneca can be followed by Pfizer or Moderna, three months or more after the second dose;
(3) two doses of Pfizer or Moderna can be followed by Pfizer or Moderna, six months or more after the second dose;
(4) mixed vaccination of Sinovac or Sinopharm and AstraZeneca can be followed by AstraZeneca or Pfizer or Moderna, three months or more after the second dose;
(5) mixed vaccination of Sinovac or Sinopharm and Pfizer can be followed by Pfizer or Moderna, three months after the second dose;
(6) mixed vaccination of AstraZeneca and Pfizer can be followed by Pfizer or Moderna, six months or more after the second dose.
CCSA urges the public to get a booster dose to help protect themselves from severe illness and fatality.