ABSTRACT
INTRODUCTION:
We documented the total spike antibody (S-Ab),
IgG S-Ab and
neutralizing antibody (N-Ab) responses of
BNT162b2/CoronaVac vaccinees up to 90 days post-booster
dose.
METHODS:
We included 32 homologous regimen CoronaVac vaccinees and 136
BNT162b2 mRNA vaccinees. We tested their total S-Ab (Roche),
IgG (Abbott) and N-Ab (Snibe) levels at set
time points from January 2021 to April 2022. All subjects were deemed to be COVID-19-naïve either via clinical
history (CoronaVac vaccinees) or
nucleocapsid antibody testing (
BNT162b2 vaccinees).
RESULTS:
All
antibodies peaked 20-30 days post-inoculation. In
BNT162b2 vaccinees, all post-booster
antibodies were significantly higher than second-
dose peaks. In CoronaVac vaccinees,
IgG showed no significant differences between peak third-/second-
dose titers (difference of 56.0 BAU/mL, 95% CI of -17.1 to 129, p = 0.0894). The post-
vaccination titers of all
antibodies in
BNT162b2 vaccinees were significantly higher than those in CoronaVac vaccinees at all
time points. Post-booster, all
antibodies declined in 90 days; the final total/
IgG/N-Ab titers were 7536 BAU/mL, 1276 BAU/mL and 12.5 µg/mL in
BNT162b2 vaccinees and 646 BAU/mL, 62.4 BAU/mL and 0.44 µg/mL in CoronaVac vaccinees.
CONCLUSION:
The
mRNA vaccine generated more robust total S-Ab,
IgG and N-Ab responses after the second and third
vaccinations.