Effectiveness of the WHO-Authorized COVID-19 Vaccines: A Rapid Review of Global Reports till 30 June 2021

  1. Chang-Jie Cheng
  2. Chun-Yi Lu
  3. Ya-Hui Chang
  4. Yu Sun
  5. Hai-Jui Chu
  6. Chun-Yu Lee
  7. Chang-Hsiu Liu
  8. Cheng-Huai Lin
  9. Chien-Jung Lu
  10. Chung-Yi Li

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Abstract

Large clinical trials have proven the efficacy of the COVID-19 vaccine, and the number of studies about the effectiveness rapidly grew in the first half of the year after mass vaccination was administrated globally. This rapid review aims to provide evidence syntheses as a means to complement the current evidence on the vaccine effectiveness (VE) against various outcomes in real-world settings. Databases (PubMed, EMBASE, and MedRxiv) were searched up to 30 June 2021, (PROSPERO ID: 266866). A total of 39 studies were included, covering over 15 million participants from 11 nations. Among the general population being fully vaccinated, the VE against symptomatic SARS-CoV-2 infection was estimated at 89–97%, 92% (95% CI, 78–97%), and 94% (95% CI, 86–97%) for BNT162b2, ChAdOx1, and mRNA-1273, respectively. As for the protective effects against B.1.617.2-related symptomatic infection, the VE was 88% (95% CI, 85.3–90.1%) by BNT162b2 and 67.0% (95% CI, 61.3–71.8%) by ChAdOx1 after full vaccination. This review revealed a consistently high effectiveness of certain vaccines among the general population in real-world settings. However, scarce data on the major variants of SARS-CoV-2 and the shortness of the study time may limit the conclusions to the mRNA vaccines and ChAdOx1.

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  1. Version published to 10.3390/vaccines9121489
  2. ScreenIT

    SciScore for 10.1101/2021.08.23.21262500: (What is this?)

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

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variableWe excluded the following researches: in vitro studies, animal studies, experimental clinical trials, systematic reviews or meta-analyses, diagnostic studies, methodological publications, editorial-style reviews, abstracts of posters, secondary analyses, studies with only immunogenicity data, safety reports or post-infection treatment, and articles with analyses only on very specific target population such as veterans, dentists, pregnant women, and patients with malignancy or mental illness.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    The search terms in PubMed and EMBASE were “effectiveness”, “Covid-19 vaccine”, and publish time “2021”.
    EMBASE
    suggested: (EMBASE, RRID:SCR_001650)
    While screening the title and abstracts of the relevant articles in PubMed, similar researches with titles shown on the web page were also checked.
    PubMed
    suggested: (PubMed, RRID:SCR_004846)
    Quality assessment, data extraction and synthesis: After identification of all relevant articles, quality assessment was performed based on ROBINS-I of Cochrane Handbook to assess the risk of bias.
    Cochrane Handbook
    suggested: None

    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:
    There are several barriers and limitations in this study. First, literature about the VE against Covid-19 are rapidly evolving and growing exponentially. In this review, 15 of 39 included studies are preprint articles up to June 30, 2021. While we were processing the review and extracting the data in July, five studies have been accepted with their data changed in online version 19, 31, 34, 37, 45, 51–53, 60 so that we need to constantly update the data accordingly before submission. Second, these included studies were disproportionately from countries in Europe, North America, and Israel, and were mostly focused on BNT162b2, because these countries have higher priority and access to a large amount of Covid-19 vaccines than most countries in other regions in the first half of 2021.6 In addition, shorter dosing intervals and larger vaccine supply in these nations also make the data of VE associated with BNT162b2 much more comprehensive than other vaccines. Longer dosing intervals made the full vaccination reports of ChAdOx1 much fewer in number than those on mRNA vaccines among the included articles over the past months. Furthermore, the VE assessment reports on CoronaVac and Ad26.COV2.S are also too few to draw conclusions. Third, the heterogeneity across studies in dosing interval, timing of outcome measurement, or different target population between vaccine types due to supply chain issues make meta-analyses difficult at present. Fourth, the VE estimates of all the studies ...

    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

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  3. Version published to 10.1101/2021.08.23.21262500v1 on medRxiv