ABSTRACT
The COVID-19 pandemic is going on, which makes it crucial to prevent the spread of coronavirus disease. Vaccination is the only way of specific prevention of COVID-19. The SARS-CoV-2 virus is continuously evolving and new variants appear. Moreover, the effectiveness of protective immunity after vaccination tends to decrease over several months. Booster vaccination may be the solution to these problems. The booster is an extra vaccination that helps to reactivate the immunity against COVID-19. Booster doses can be homologous (the same as the primary vaccine) and heterologous (different from the primary vaccine). It is of current interest to study heterologous vaccination as the injection of different vaccines may result in a more intense immune response. Furthermore, the same vaccine may not be available at the time of booster vaccination. This review is aimed at summarizing the key research findings in the field of booster vaccination against COVID-19. © 2022 Booster vaccination against. All rights reserved.