BBIBP-CorV (Sinopharm) vaccination- induced immunity is affected by age, gender and prior COVID-19 and activates responses to spike and other antigens

Abstract

Long-term solutions against SARS-CoV-2 infections require understanding of immune protection induced by different vaccine COVID-19 formulations. We investigated humoral and cellular immunity induced by Sinopharm (BBIBP-CorV) in a region of high SARS-CoV-2 seroprevalence. Levels of IgG antibodies to SARS-CoV-2 spike protein and its receptor-binding domain (RBD) were determined 24-weeks. Cellular immunity was investigated using a commercially available IFN-γ release assay to SARS-CoV-2 spike (Ag1 and 2) and extended genome antigens (Ag3). Increasing IgG seropositivity to Spike protein and RBD was observed post-vaccination. Seropositivity was reduced in those over 50 years and raised in females and those with prior COVID-19. After 20 weeks post-vaccination, only one third of participants had positive T cell responses to SARS-CoV-2 antigens. Prior COVID-19 impacted IFNγ responses, with reactivity enhanced in those infected earlier. The frequency of IFNγ responses was highest to extended genome antigen set. Overall, BBIBP-CorV- induced antibody responses were impacted by age, gender and prior COVID-19. Cellular immunity was present in a limited number of individuals after 20 weeks but was enhanced by prior infection. This suggests the need for booster vaccinations in older individuals. BBIBP-CorV induced cellular activation is broader than to spike, requiring further study to understand how to monitor vaccine effectiveness.

RBD-specific antibody response after two doses of different SARS-CoV-2 vaccines during the mass vaccination campaign in Mongolia

“…Association of the seropositivity and titer of protective antibodies after two shot vaccination with sex, age, and residence of vaccinees were reported ambiguous PLOS ONE [35,36]. Age was often reported as a predictor of seropositivity in subjects who vaccinated with the BBIBP-CorV vaccine [13,35,37]. We found a 98.2% seropositivity after two shots of the BNT162b vaccine among immunocompromised individuals, including patients who received immunosuppressive therapy and PLWHA.…”

“…So far, we cannot give an exclusive explanation of this phenomenon since the sociodemographic pattern of these groups was approximately the same (S1 Table ). Association of the seropositivity and titer of protective antibodies after two shot vaccination with sex, age, and residence of vaccinees were reported ambiguous PLOS ONE [35,36]. Age was often reported as a predictor of seropositivity in subjects who vaccinated with the BBIBP-CorV vaccine [13,35,37].…”