Immune responses to Sinopharm/BBIBP-CorV in individuals in Sri Lanka

Journal article

As there are limited data of the immunogenicity of the Sinopharm/BBIBP-CorV in different populations, antibody responses against different SARS-CoV-2 variants of concern and T cell responses, we investigated the immunogenicity of the vaccine, in individuals in Sri Lanka. SARS-CoV-2-specific antibodies were measured in 282 individuals who were seronegative at baseline, and ACE2 receptor blocking antibodies, antibodies to the receptor-binding domain (RBD) of the wild-type (WT), alpha, beta and delta variants, ex vivo and cultured IFNγ ELISpot assays, intracellular cytokine secretion assays and B cell ELISpot assays were carried out in a sub cohort of the vaccinees at 4 and 6 weeks (2 weeks after the second dose). Ninety-five percent of the vaccinees seroconverted, although the seroconversion rates were significantly lower (p < 0.001) in individuals >60 years (93.3%) compared to those who were 20–39 years (98.9%); 81.25% had ACE2 receptor blocking antibodies at 6 weeks, and there was no difference in these antibody titres in vaccine sera compared to convalescent sera (p = 0.44). Vaccinees had significantly less (p < 0.0001) antibodies to the RBD of WT and alpha, although there was no difference in antibodies to the RBD of beta and delta compared to convalescent sera; 27.7% of 46.4% of vaccinees had ex vivo IFNγ and cultured ELISpot responses respectively, and IFNγ and CD107a responses were detected by flow cytometry. Sinopharm/BBIBP-CorV appeared to induce a similar level of antibody responses against ACE2 receptor, delta and beta as seen following natural infection.

Authors: Jeewandara, C; Aberathna, IS; Pushpakumara, PD; Kamaladasa, A; Guruge, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Immunology
• Volume: 167
• Issue: 2
• Pages: 275-285
• Place of publication: England
• Publication date: 2022-07-12
• Acceptance date: 2022-06-15
• DOI: 10.1111/imm.13536
• EISSN: 1365-2567
• ISSN: 0019-2805
• Pmid: 35758860
• Language: English
• Keywords: viral; T cell; B cell; vaccination; FFR; antibodies