Lessons Learned from Global Administration of Sinopharm (BBIBP-CorV) Vaccine and Its Efficacy against COVID-19 in Older People

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 pertaining lessons are highlighted. 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 programs. Secondly, for older people, antibody responses alone may not indicate the level of protection provided by the vaccines, as cell mediated immunity is a better determinant of immunity in this age group. Finally, suggestions are given to improve the immune responses in older people, such as heterologous vaccination and booster doses.