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

  1. Yaowen Zhang
  2. Jihane Belayachi
  3. Yunkai Yang
  4. Qiang Fu
  5. Lance Rodewald
  6. Hongling Li
  7. Bing Yan
  8. Ying Wang
  9. Yanna Shen
  10. Qian Yang
  11. Weiyun Mu
  12. Rong Tang
  13. Chen Su
  14. Tianfang Xu
  15. Majdouline Obtel
  16. Abdelkader Mhayi
  17. Rachid Razine
  18. Redouane Abouqal
  19. Yuntao Zhang
  20. Xiaoming Yang

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Abstract

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.

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  1. Version published to 10.1186/s12889-022-14016-9
  2. ScreenIT

    SciScore for 10.1101/2022.04.23.22274112: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIACUC: Ethical review: The study was approved by the Rabat Ethical Review Committee for Biomedical Research at Mohammed V University.
    Consent: A waiver of informed consent was granted for this observational study.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    All data analyses were performed with SAS software (version 9.4, SAS Institute Inc., Cary, NC, USA).
    SAS Institute
    suggested: (Statistical Analysis System, RRID:SCR_008567)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Our study has several limitations. First, there were no analyses of virus strains, therefore BBIBP-CorV VE against specific SARS-CoV-2 variants could not be estimated. Second, we did not have individual-level comorbidity data, precluding subgroup analysis of VE. Third, we did not have data on reasons for critical hospitalization. As a result, our study could not distinguish critical hospitalization caused by SARS-CoV-2 infection from critical hospitalization coincidental to SARS-CoV-2 infection. This limitation may partially explain the lower VE among older subjects, who are more likely to be hospitalized than younger subjects. For example, Emborg[35] and colleagues found that BNT162b2 mRNA VEs against all-cause hospital admissions and COVID-19-related hospital admissions among ≥65-year-olds were 37% and 87%, respectively. Fourth, the timing of the study was such that too few individuals had received booster doses, precluding an analysis of BBIBP-CorV booster dose VE. In conclusion, consistent with the results of phase III clinical trials, BBIBP-CorV vaccine is highly protective against severe and critical hospitalization in real-world conditions. VE was found to be greater in working age adults than elderly adults. Monitoring VE is important for adjusting vaccine recommendations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

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  3. Version published to 10.1101/2022.04.23.22274112v1 on medRxiv