Waning antibody levels after COVID-19 vaccination with mRNA Comirnaty and inactivated CoronaVac vaccines in blood donors, Hong Kong, April 2020 to October 2021
Shirley L. L. Kwok, Samuel M. S. Cheng, Jennifer NS Leung, Kathy Leung, Cheuk‐Kwong Lee, Malik Peiris, Joseph T. Wu
Abstract
The mRNA vaccine Comirnaty and the inactivated vaccine CoronaVac are both available in Hong Kong's COVID-19 vaccination programme. We observed waning antibody levels in 850 fully vaccinated (at least 14 days passed after second dose) blood donors using ELISA and surrogate virus neutralisation test. The Comirnaty-vaccinated group's (n = 593) antibody levels remained over the ELISA and sVNT positive cut-offs within the first 6 months. The CoronaVac-vaccinated group's (n = 257) median antibody levels began to fall below the cut-offs 4 months after vaccination.
Topics & Concepts
VaccinationMedicineAntibodyCoronavirus disease 2019 (COVID-19)VirologySevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)2019-20 coronavirus outbreakImmunologyVirusOutbreakInternal medicineInfectious disease (medical specialty)DiseaseSARS-CoV-2 and COVID-19 ResearchHeparin-Induced Thrombocytopenia and ThrombosisCOVID-19 Clinical Research Studies