Shyh Poh Teo,
Volume 8, Issue 2 (12-2021)
Abstract
Sinopharm (BBIBP-CorV) is an inactivated whole-virus COVID-19 vaccine. The phase 3 trial showed an efficacy of up to 78% in preventing symptomatic COVID-19 infections. However, there have been questions raised regarding in its efficacy in older people. In this paper, several lessons are highlighted from this. Firstly, there is a need to take into account the heterogeneity of COVID-19 vaccine studies, such as representation of older people; and whether the results are generalizable to the target population of immunization programmes. Secondly, for older people, antibody responses alone may not indicate the level of protection afforded by vaccines, as cell mediated immunity is a better marker of immunity. Finally, suggestions are given to improve the immune response in older people, such as heterologous vaccination and booster doses.