Clin Exp Vaccine Res.  2022 May;11(2):209-216. 10.7774/cevr.2022.11.2.209.

Heterologous prime-boost with the mRNA-1273 vaccine among CoronaVac-vaccinated healthcare workers in Indonesia

  • 1Siloam Hospitals Lippo Cikarang, Bekasi, Indonesia
  • 2Faculty of Medicine, Universitas Pelita Harapan, Tangerang, Indonesia
  • 3Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
  • 4Mochtar Riady Institute for Nanotechnology, Tangerang, Indonesia
  • 5Department of Biology, Faculty of Science and Technology, Universitas Pelita Harapan, Tangerang, Indonesia


This study was performed to investigate humoral immune response and adverse events upon the heterologous prime-boost with a single dose of the mRNA-1273 vaccine among fully CoronaVac-vaccinated, infection-naïve healthcare workers in Indonesia.
Materials and Methods
One hundred twenty-five eligible healthcare workers were recruited from one hospital for this prospective cohort study. Blood collection was conducted twice, i.e., on 7 days before and 28 days after the booster vaccination. The titer of anti-SARS-CoV-2 receptor-binding domain (RBD) antibodies was quantified accordingly. The post-vaccination adverse event was recorded for both CoronaVac and mRNA-1273 vaccinations. Any breakthrough infection was monitored during the follow-up period. Wilcoxon matched-pairs signed rank test was used to test differences between groups.
A significant increase was observed in the titer of anti-SARS-CoV-2 RBD antibodies upon receiving the mRNA-1273 booster (geometric mean titers of 65.57 and 47,445 U/mL in pre- and post-booster, respectively), supporting the argument to use heterologous prime-boost vaccination to improve the protection against COVID-19 in a high-risk population. The mRNA-1273 vaccine, however, caused a higher frequency of adverse events than the CoronaVac vaccine. Nonetheless, the adverse events were considered minor medical events and temporary as all subjects were not hospitalized and fully recovered. Of note, no breakthrough infection was observed during the follow-up to 12 weeks post-booster.
The heterologous prime-boost vaccination of healthcare workers with a single dose of the mRNA-1273 vaccine generated a significant elevation in humoral immune response towards RBD of SARS-CoV-2 and was associated with a higher frequency, but minor and transient, adverse events.


Coronavirus disease 2019; Heterologous prime-boost; CoronaVac; 2019-nCoV vaccine mRNA-1273; Anti-SARS-CoV-2 RBD
Full Text Links
  • CEVR
export Copy
  • Twitter
  • Facebook
Similar articles
Copyright © 2023 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: