Immunogenicity of two‐dose sinopharm BBIB‐CorV vaccine in Morocco: One‐year follow‐up and neutralizing activity against severe acute respiratory syndrome coronavirus 2 variants of concern

Abstract

Abstract Background This study aimed to evaluate the immunogenicity of a two‐dose Sinopharm BBIB‐CorV (Vero cells) vaccine against SARS‐CoV‐2, at 28 days, 6 months, and 1‐year postvaccination. And assess the capacity of two‐dose vaccine recipients to neutralize SARS‐CoV‐2 strains B.1 (Wuhan/D614G), B.1.1.7 (Alpha), AY.33 (Delta), or BA.5.2.2 (Omicron) variants of concern (VOCs). Methods A prospective matched case–control cohort study was conducted at the Military Hospital of Rabat, Morocco between February 2021 and 2022. Immunogenicity was evaluated by standard Microneutralization (MN) assay against four variants (Wuhan D614G, Alpha, Delta, and Omicron). Results The overall positive neutralizing rates for vaccine recipients against B.1 D614G were 72.09%, 74.82%, and 75.19% on 28‐, 180‐, 365‐ day respectively. The proportion of NAbs targeting the Wuhan D614G, and Alpha variants under the BBIBP‐CorV vaccination was high on Day 28‐ and 6 months postvaccination. Conclusion The immunogenic response to the newly emerging SARS‐CoV‐2 variants of concern (VOCs), such as Delta and Omicron was comparatively reduced. As a result, it is recommended that additional boost vaccinations be considered.

Keywords

• BBIBP‐CorV Sinopharm
• immunogenicity
• microneutralization assay
• neutralizing antibodies
• SARS‐CoV‐2