Waning antibody levels after COVID-19 vaccination with mRNA Comirnaty and inactivated CoronaVac vaccines in blood donors, Hong Kong, April 2020 to October 2021

Euro Surveill. 2022 Jan;27(2):2101197. doi: 10.2807/1560-7917.ES.2022.27.2.2101197.

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.

Keywords: BNT162b2; COVID-19; CoronaVac; SARS-CoV-2; antibody; vaccine.

MeSH terms

  • Antibodies, Viral
  • Blood Donors
  • COVID-19 Vaccines*
  • COVID-19*
  • Hong Kong
  • Humans
  • RNA, Messenger
  • SARS-CoV-2
  • Vaccination
  • Vaccines, Inactivated
  • Vaccines, Synthetic
  • mRNA Vaccines

Substances

  • Antibodies, Viral
  • COVID-19 Vaccines
  • RNA, Messenger
  • Vaccines, Inactivated
  • Vaccines, Synthetic
  • mRNA Vaccines