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Meta-Analysis on Effectiveness of Janssen Vaccination in Prevention of Corona Virus Disease in United States of America, Brazil and South Africa

Audi Najib Isyaku Nurudeen Sanusi Akilu Mary Unekwu Adehi

Subject area: Science,Engineering and Technology  ·  Area of research: Statistics and Data Analytics

DOI: https://doi.org/10.64388/IREV9I8-1714344

Abstract

Meta-analyses are powerful tools for synthesizing evidence on vaccine effectiveness, though results may be affected by heterogeneity and bias. This study examined the effectiveness of the Janssen COVID-19 vaccine in preventing coronavirus disease across multiple regions. A meta-analysis of 20 studies involving 39,321 participants (19,630 vaccinated; 19,691 placebo) was conducted. Standardized mean differences were pooled using both fixed- and random-effects models. Heterogeneity was assessed with Cochran’s Q and the I² statistic, while potential publication bias was evaluated using Egger’s regression test and a funnel plot. Substantial heterogeneity was observed among studies (Q = 85.45, p < 0.001; I² = 77.8%), indicating variation in study outcomes. The random-effects model produced a pooled effect size of 0.008 (95% CI: –0.011 to 0.027), suggesting no consistent overall effect. Egger’s test (p = 0.240) and funnel plot inspection revealed no evidence of publication bias. Although the pooled effect was negligible, the high heterogeneity indicates that vaccine effectiveness likely varies by setting, population, and circulating variants. Importantly, absence of publication bias strengthens the reliability of the analysis. In the broader context of vaccine literature, the Janssen vaccine has been shown to reduce hospitalization and severe outcomes, particularly among older adults, though its effectiveness is lower than that of mRNA vaccines. These findings underscore the need for cautious interpretation of pooled estimates and highlight the importance of context-specific vaccine policies. Further subgroup analyses are recommended to clarify sources of variability and guide targeted immunization strategies.

Keywords

Janssen Vaccination, Vaccine Effectiveness, COVID-19 Prevention, Meta-analysis, Heterogeneity

References

[1] Anonymous. (2020). EUA-FACTSHEET. Retrieved November 1, 2021, from www.jassenCOVID19Vaccine.com/EUA-factsheet

[2] Anonymous. (2021, October 29). FDA Authorizes Pfizer-BioNTech Covid-19 Vaccine for Emergency use in Children 5 through 11 Years of Age. Retrieved September 5, 2022, from https://www.fda.gov/news-events/press-announcements/fda

[3] Anonymous. (2021, August 23). Penn Medicine News. (Penn Medicine News) Retrieved January 5, 2022, from Penn: https://www.pennmedicine.org/news/news-releases/2021/august/covid19-mrna-vaccine-that-uses-fundamental-penn-technology-receives-fda-approval

[4] Brit Long, R. B. (2021, November). Thrombosis with Thrombocytopenia Syndrome Associated with COVID-19 Vaccines. The American Journal of Emergency Medicine, 2021(49), 58-61.

[5] Center, J. H. (2022, January 1). Johns Hopkins University Coronavirus Resource Center. Retrieved 2022, from https://coronavirus.jhu.edu/map.html

[6] Harcourt, J. (2020). Severe Acute Respiratory Syndrome Coronavirus 2 from Patient with Coronavirus Disease, United States. Emerging Infectious Disease, 26(6), 1266-1273.

[7] Heidi L. Moline, M. W. (2021, August 13). Effectiveness of COVID-19 Vaccines in Preventing Hospitalization Among Adults Aged>or=65 Years- COVID-NET, 13 States, February-April 2021. Morbidity and Mortality Weekly Report (MMWR), 70(32), pp. 1088-1093.

[8] Jeroen Luyten, P. B. (2016). The Social Value of Vaccination Programs: Beyond Cost-Effectiveness. Health Affairs (Project Hope), 35(2), 212-218.

[9] Jerome Custers, D. K. (2021, May 21). Vaccines Based on Replication Incompetent Ad26 Viral Vectors: Standardized Template with Key Considerations for a Risk/Benefit Assessment. National Library of Medicine, 39(22), pp. 3081-3101.

[10] MedlinePlus. (2022). Retrieved from https://medlineplus.gov/genetics/condition/guillain-barre-syndrome/

[11] Michael Borenstein, L. V. (2009). Introduction to Meta-Analysis. Chichester: John Wiley & Sons, Ltd.

[12] Mohammed Rilwan, M. U. (2021). Meta-Analysis on the Effect of Tamiflu in Patients Infected with Flu in Some Areas around US and Asia. International Journal of Science and Research (IJSR), 10(6), 1737-1740.

[13] Rachael Zimlich, B. R. (2022, May 9). An Overview of the Johnson & Johnson COVID-19 Vaccine. Verywell Health.

[14] Tregoning J. S., F. K. (2021). Progress of the COVID-19 Vaccine Effort: Viruses, Vaccines and Variants Versus Efficacy, Effectiveness and Escape. Nature Reviews Immunology, 21(2021), 626-634.

[15] Van Doremalen N., L. T. (2020). ChAdOx1 nCoV-19 Vaccine Prevents SARS-Cov-2 Pneumonia in Rhesus Macaques. Nature, 2020(586), 578-582.

How to cite this paper

Audi Najib Isyaku, Nurudeen Sanusi Akilu , Mary Unekwu Adehi "Meta-Analysis on Effectiveness of Janssen Vaccination in Prevention of Corona Virus Disease in United States of America, Brazil and South Africa" Iconic Research And Engineering Journals Volume 9 Issue 8 2026 Page 1909-1917 https://doi.org/10.64388/IREV9I8-1714344
Audi Najib Isyaku, Nurudeen Sanusi Akilu , Mary Unekwu Adehi "Meta-Analysis on Effectiveness of Janssen Vaccination in Prevention of Corona Virus Disease in United States of America, Brazil and South Africa" Iconic Research And Engineering Journals, vol. 9, no. 8, Feb. 2026, doi: https://doi.org/10.64388/IREV9I8-1714344
Audi Najib Isyaku, Nurudeen Sanusi Akilu , Mary Unekwu Adehi (2026). Meta-Analysis on Effectiveness of Janssen Vaccination in Prevention of Corona Virus Disease in United States of America, Brazil and South Africa. Iconic Research And Engineering Journals, 9(8). doi: https://doi.org/10.64388/IREV9I8-1714344
Audi Najib Isyaku, Nurudeen Sanusi Akilu , Mary Unekwu Adehi "Meta-Analysis on Effectiveness of Janssen Vaccination in Prevention of Corona Virus Disease in United States of America, Brazil and South Africa" Iconic Research And Engineering Journals, vol. 9, no. 8, Feb. 2026. Crossref, https://doi.org/10.64388/IREV9I8-1714344
@article{1714344,
      author = {Audi Najib Isyaku, Nurudeen Sanusi Akilu , Mary Unekwu Adehi},
      title = {Meta-Analysis on Effectiveness of Janssen Vaccination in Prevention of Corona Virus Disease in United States of America, Brazil and South Africa},
      journal = {Iconic Research And Engineering Journals},
      year = {2026},
      volume = {9},
      number = {8},
      pages = {1909-1917},
      issn = {2456-8880},
      url = {https://www.irejournals.com/formatedpaper/1714344.pdf},
      abstract = {Meta-analyses are powerful tools for synthesizing evidence on vaccine effectiveness, though results may be affected by heterogeneity and bias. This study examined the effectiveness of the Janssen COVID-19 vaccine in preventing coronavirus disease across multiple regions. A meta-analysis of 20 studies involving 39,321 participants (19,630 vaccinated; 19,691 placebo) was conducted. Standardized mean differences were pooled using both fixed- and random-effects models. Heterogeneity was assessed with Cochran’s Q and the I² statistic, while potential publication bias was evaluated using Egger’s regression test and a funnel plot. Substantial heterogeneity was observed among studies (Q = 85.45, p < 0.001; I² = 77.8%), indicating variation in study outcomes. The random-effects model produced a pooled effect size of 0.008 (95% CI: –0.011 to 0.027), suggesting no consistent overall effect. Egger’s test (p = 0.240) and funnel plot inspection revealed no evidence of publication bias. Although the pooled effect was negligible, the high heterogeneity indicates that vaccine effectiveness likely varies by setting, population, and circulating variants. Importantly, absence of publication bias strengthens the reliability of the analysis. In the broader context of vaccine literature, the Janssen vaccine has been shown to reduce hospitalization and severe outcomes, particularly among older adults, though its effectiveness is lower than that of mRNA vaccines. These findings underscore the need for cautious interpretation of pooled estimates and highlight the importance of context-specific vaccine policies. Further subgroup analyses are recommended to clarify sources of variability and guide targeted immunization strategies.},
      keywords = {Janssen Vaccination, Vaccine Effectiveness, COVID-19 Prevention, Meta-analysis, Heterogeneity},
      month = {February},
      doi = {https://doi.org/10.64388/IREV9I8-1714344}
  }