The DOI matches its Crossref record; 53 of the 53 references it cites were found in a registry or an index.
Efficacy and Safety of COVID-19 Vaccines: A Systematic Review and Meta-Analysis of Randomized Clinical Trials
Open accessAbstract
The current study systematically reviewed, summarized and meta-analyzed the clinical features of the vaccines in clinical trials to provide a better estimate of their efficacy, side effects and immunogenicity. All relevant publications were systematically searched and collected from major databases up to 12 March 2021. A total of 25 RCTs (123 datasets), 58,889 cases that received the COVID-19 vaccine and 46,638 controls who received placebo were included in the meta-analysis. In total, mRNA-based and adenovirus-vectored COVID-19 vaccines had 94.6% (95% CI 0.936–0.954) and 80.2% (95% CI 0.56–0.93) efficacy in phase II/III RCTs, respectively. Efficacy of the adenovirus-vectored vaccine after the first (97.6%; 95% CI 0.939–0.997) and second (98.2%; 95% CI 0.980–0.984) doses was the highest against receptor-binding domain (RBD) antigen after 3 weeks of injections. The mRNA-based vaccines had the highest level of side effects reported except for diarrhea and arthralgia. Aluminum-adjuvanted vaccines had the lowest systemic and local side effects between vaccines’ adjuvant or without adjuvant, except for injection site redness. The adenovirus-vectored and mRNA-based vaccines for COVID-19 showed the highest efficacy after first and second doses, respectively. The mRNA-based vaccines had higher side effects. Remarkably few experienced extreme adverse effects and all stimulated robust immune responses.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Quantifying heterogeneity in a meta‐analysis
Higgins, J. P. T., & Thompson, S. G. (2002) · Statistics in Medicine · doi:10.1002/sim.1186 · Cited by 36,763
PRISMA-P Group, Moher, D., Shamseer, L., Clarke, M., Ghersi, D., Liberati, A., Petticrew, M., Shekelle, P., & Stewart, L. A. (2015) · Systematic Reviews · doi:10.1186/2046-4053-4-1 · Cited by 26,223
Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine
Polack, F. P., Thomas, S. J., Kitchin, N., Absalon, J., Gurtman, A., Lockhart, S., Perez, J. L., Pérez Marc, G., Moreira, E. D., Zerbini, C., et al. (2020) · New England Journal of Medicine · doi:10.1056/nejmoa2034577 · Cited by 14,592
Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine
Baden, L. R., El Sahly, H. M., Essink, B., Kotloff, K., Frey, S., Novak, R., Diemert, D., Spector, S. A., Rouphael, N., Creech, C. B., et al. (2021) · New England Journal of Medicine · doi:10.1056/nejmoa2035389 · Cited by 10,119
mRNA vaccines — a new era in vaccinology
Pardi, N., Hogan, M. J., Porter, F. W., & Weissman, D. (2018) · Nature Reviews Drug Discovery · doi:10.1038/nrd.2017.243 · Cited by 4,667 · cited 2×
“The resulting antigen triggers an immune response, including the production of antibodies [5].”
BackgroundVoysey, M., Clemens, S. A. C., Madhi, S. A., Weckx, L. Y., Folegatti, P. M., Aley, P. K., Angus, B., Baillie, V. L., Barnabas, S. L., Bhorat, Q. E., et al. (2021) · The Lancet · doi:10.1016/s0140-6736(20)32661-1 · Cited by 4,616
Self-citationAn mRNA Vaccine against SARS-CoV-2 — Preliminary Report
Jackson, L. A., Anderson, E. J., Rouphael, N. G., Roberts, P. C., Makhene, M., Coler, R. N., McCullough, M. P., Chappell, J. D., Denison, M. R., Stevens, L. J., et al. (2020) · New England Journal of Medicine · doi:10.1056/nejmoa2022483 · Cited by 3,237
Coronavirus biology and replication: implications for SARS-CoV-2
V’kovski, P., Kratzel, A., Steiner, S., Stalder, H., & Thiel, V. (2021) · Nature Reviews Microbiology · doi:10.1038/s41579-020-00468-6 · Cited by 3,197
RNA-Based COVID-19 Vaccine BNT162b2 Selected for a Pivotal Efficacy Study
Walsh, E. E., Frenck, R., Falsey, A. R., Kitchin, N., Absalon, J., Gurtman, A., Lockhart, S., Neuzil, K., Mulligan, M. J., Bailey, R., et al. (2020) · doi:10.1101/2020.08.17.20176651 · Cited by 2,615
Folegatti, P. M., Ewer, K. J., Aley, P. K., Angus, B., Becker, S., Belij-Rammerstorfer, S., Bellamy, D., Bibi, S., Bittaye, M., Clutterbuck, E. A., et al. (2020) · The Lancet · doi:10.1016/s0140-6736(20)31604-4 · Cited by 2,419
Cited by
Wen, W., Chen, C., Tang, J., Wang, C., Zhou, M., Cheng, Y., Zhou, X., Wu, Q., Zhang, X., Feng, Z., et al. (2022) · Annals of Medicine · doi:10.1080/07853890.2022.2034936 · Cited by 423
Choi, A., Koch, M., Wu, K., Chu, L., Ma, L., Hill, A., Nunna, N., Huang, W., Oestreicher, J., Colpitts, T., et al. (2021) · Nature Medicine · doi:10.1038/s41591-021-01527-y · Cited by 396
Liu, Q., Qin, C., Liu, M., & Liu, J. (2021) · Infectious Diseases of Poverty · doi:10.1186/s40249-021-00915-3 · Cited by 341
Efficacy, Immunogenicity and Safety of COVID-19 Vaccines: A Systematic Review and Meta-Analysis
Sharif, N., Alzahrani, K. J., Ahmed, S. N., & Dey, S. K. (2021) · Frontiers in Immunology · doi:10.3389/fimmu.2021.714170 · Cited by 230
Comparison of the immunogenicity of BNT162b2 and CoronaVac COVID ‐19 vaccines in Hong Kong
Mok, C. K. P., Cohen, C. A., Cheng, S. M. S., Chen, C., Kwok, K., Yiu, K., Chan, T., Bull, M., Ling, K. C., Dai, Z., et al. (2022) · Respirology · doi:10.1111/resp.14191 · Cited by 162
“7–11 The safety, immunogenicity and efficacy of these vaccines have been evaluated in separate clinical trials, 12–14 but there are few ‘head-to-head’ comparisons of different vaccines.”
Metadata
- Authors
- Pormohammad, A., Zarei, M., Ghorbani, S., Mohammadi, M., Razizadeh, M. H., Turner, D. L., & Turner, R. J.
- Venue
- Vaccines
- Publisher
- MDPI AG
- Published
- 2021-05-06
- Volume
- 9
- Issue
- 5
- Pages
- 467
- ISSN
- 2076-393X (ISSN-L)
- OpenAlex
- W3157022736
- Cited by
- 339
- References
- 53
- FWCI
- 10.25
- Type
- journal article
- Language
- en
- Open access
- gold
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: Efficacy and Safety of COVID-19 Vaccines: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. https://app.cochat.ai/papers/10.3390/vaccines9050467
- The paper
- Pormohammad, A., Zarei, M., Ghorbani, S., Mohammadi, M., Razizadeh, M. H., Turner, D. L., & Turner, R. J. (2021). Efficacy and Safety of COVID-19 Vaccines: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Vaccines. https://doi.org/10.3390/vaccines9050467
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
