Heterologous booster COVID-19 vaccination elicited potent immune responses in HCWs

Saltoğlu N., Dinç H. Ö., Balkan İ. İ., Can G., Özbey D., Beytur A. N., ...More

Diagnostic Microbiology and Infectious Disease, vol.104, no.2, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 104 Issue: 2
  • Publication Date: 2022
  • Doi Number: 10.1016/j.diagmicrobio.2022.115758
  • Journal Name: Diagnostic Microbiology and Infectious Disease
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, EMBASE, Environment Index, MEDLINE, Veterinary Science Database
  • Keywords: COVID-19, Vaccine, BNT162b2, CoronaVac, Antibody
  • Istanbul Medipol University Affiliated: Yes


The objective of our study was to evaluate the antibody responses of health care workers (HCWs) who were vaccinated with booster dose BNT162b2 6 months after 2 doses of the CoronoVac vaccine. The study included 318 HCWs vaccinated with inactive CoronaVac SARS-CoV-2 vaccine in 2 doses. Anti-spike/RBD IgG levels were measured immediately before and 1 month after the booster dose. In the sixth month after CoronaVac vaccination, the median of antibody levels of 1212.02 AU/ML, while it was 9283 AU/mL after BNT162b2 vaccination. IgG antibody titers of over 1050 AU/mL (which is equivalent to 1:80 dilution in the plaque reduction neutralization test) were detected in HCWs 15.09% and 97.8%, respectively. Our results showed that antibody titers increased 8-fold after the booster dose. We believe that the administration of the mRNA vaccine as a booster dose can provide more effective protection against COVID-19 infection, especially in individuals with risk factors.