THE LEVEL OF IG ANTI‐RBD SARS‐COV‐2 AFTER TWO DOSES OF CORONAVAC VACCINE

The safety and immunogenicity of the two‐dose injections of the CoronaVac vaccine (Sinovac Life Sciences) have been reported in Phase 1 and 2 trials. In this study, a total of 131 subjects, consisting of 59 male (45%) and 72 female (55%) healthcare workers (mean age overall, 35.07 years old were included. The antibody titers of vaccinees with a pre‐existing history of SARS‐CoV‐2 infection tend to be higher than those without a pre‐ existing history of SARS‐CoV‐2 infection and also exceeded the mean of antibody titers evaluated in subjects without a pre‐existing history of SARS‐CoV‐2 infection, similar to previously reported studies utilizing Pfizer BNT162b2 and SPUTNIK V vaccines. In conclusion, although two doses of administration of CoronaVac vaccine elicited the development of humoral immunity against SARS‐CoV‐2, particularly Ig anti‐RBD, the antibody level was mainly lower than the recommended value for the emergency use of convalescent plasma for the COVID‐19 treatment or patients who previously had COVID‐19 infection