Real-world study of the effectiveness of BBIBP-CorV (Sinopharm) COVID-19 vaccine in the Kingdom of Morocco

• Published in: BMC public health Vol. 22; no. 1; pp. 1 - 1584
• Main Authors: Zhang, Yaowen, Belayachi, Jihane, Yang, Yunkai, Fu, Qiang, Rodewald, Lance, Li, Hongling, Yan, Bing, Wang, Ying, Shen, Yanna, Yang, Qian, Mu, Weiyun, Tang, Rong, Su, Chen, Xu, Tianfang, Obtel, Majdouline, Mhayi, Abdelkader, Razine, Rachid, Abouqal, Redouane, Zhang, Yuntao, Yang, Xiaoming
• Format: Journal Article
• Language: English
• Published: London BioMed Central Ltd 20-08-2022; BioMed Central; BMC
• Subjects: Adults; Age; Age groups; BBIBP-CorV; Clinical trials; Coronaviruses; COVID-19; COVID-19 vaccines; Drug dosages; Effectiveness; Homology; Hospitalization; Illnesses; Immunization; Infections; Males; Older people; Polymerase chain reaction; Population; Public health; Regression analysis; Regression models; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Sex; Vaccination; Vaccine; Vaccine efficacy; Vaccines; Viral diseases; Morocco
• ISSN: 1471-2458; 1471-2458
• DOI: 10.1186/s12889-022-14016-9

Background The Kingdom of Morocco approved BBIBP-CorV (Sinopharm) COVID-19 vaccine for emergency use on 22 January 2021 in a two-dose, three-to-four-week interval schedule. We conducted a retrospective cohort study to determine real-world BBIBP-CorV vaccine effectiveness (VE) against serious or critical hospitalization of individuals RT-PCR-positive for SARS-CoV-2 during the first five months of BBIBP-CorV use in Morocco. Methods The study was conducted among adults 18-99 years old who were tested by RT-PCR for SARS-CoV-2 infection between 1 February and 30 June 2021. RT-PCR results were individually linked with outcomes from the COVID-19 severe or critical hospitalization dataset and with vaccination histories from the national vaccination registration system. Individuals with partial vaccination (< 2 weeks after dose two) or in receipt of any other COVID-19 vaccine were excluded. Unadjusted and adjusted VE estimates against hospitalization for serious or critical illness were made by comparing two-dose vaccinated and unvaccinated individuals in logistic regression models, calculated as (1-odds ratio) * 100%. Results There were 348,190 individuals able to be matched across the three databases. Among these, 140,892 were fully vaccinated, 206,149 were unvaccinated, and 1,149 received homologous BBIBP-CorV booster doses. Unadjusted, full-series, unboosted BBIBP-CorV VE against hospitalization for serious or critical illness was 90.2% (95%CI: 87.8--92.0%). Full-series, unboosted VE, adjusted for age, sex, and calendar day of RT-PCR test, was 88.5% (95%CI: 85.8--90.7%). Calendar day- and sex-adjusted VE was 96.4% (95%CI: 94.6--97.6%) for individuals < 60 years, and was 53.3% (95%CI: 39.6--63.9%) for individuals 60 years and older. There were no serious or critical illnesses among BBIBP-CorV-boosted individuals. Conclusions Effectiveness of Sinopharm's BBIBP-CorV was consistent with phase III clinical trial results. Two doses of BBIBP-CorV was highly protective against COVID-19-associated serious or critical hospitalization in working-age adults under real-world conditions and moderately effective in older adults. Booster dose vaccination was associated with complete protection, regardless of age, although only a small proportion of subjects received booster doses. Keywords: COVID-19, Vaccine, Effectiveness, BBIBP-CorV