Cited by 504SARS-CoV-2 and COVID-19 ResearchRNA Interference and Gene DeliveryImmunotherapy and Immune Responses

The DOI matches its Crossref record; 84 of the 90 references it cites were found in a registry or an index; 1 of the 134 sources its claims cite were checked for support.

The dawn of mRNA vaccines: The COVID-19 case

Open access
Verbeke, Rein, Lentacker, Ine, De Smedt, Stefaan C., Dewitte, Heleen·2021·Journal of Controlled Release

Abstract

In less than one year since the outbreak of the COVID-19 pandemic, two mRNA-based vaccines, BNT162b2 and mRNA-1273, were granted the first historic authorization for emergency use, while another mRNA vaccine, CVnCoV, progressed to phase 3 clinical testing. The COVID-19 mRNA vaccines represent a new class of vaccine products, which consist of synthetic mRNA strands encoding the SARS-CoV-2 Spike glycoprotein, packaged in lipid nanoparticles to deliver mRNA to cells. This review digs deeper into the scientific breakthroughs of the last decades that laid the foundations for the rapid rise of mRNA vaccines during the COVID-19 pandemic. As well as providing momentum for mRNA vaccines, SARS-CoV-2 represents an ideal case study allowing to compare design-activity differences between the different mRNA vaccine candidates. Therefore, a detailed overview of the composition and (pre)clinical performance of the three most advanced mRNA vaccines is provided and the influence of choices in their structural design on to their immunogenicity and reactogenicity profile is discussed in depth. In addition to the new fundamental insights in the mRNA vaccines' mode of action highlighted here, we also point out which unknowns remain that require further investigation and possibly, optimization in future mRNA vaccine development.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

This review explains how decades of mRNA, innate-immunity, and lipid-nanoparticle research enabled the rapid COVID-19 mRNA vaccines, and compares BNT162b2, mRNA-1273, and CVnCoV. It concludes that mRNA vaccines are highly efficacious and generally safe, but important unknowns remain about innate immune effects, durability, and which vaccine components drive differences in immunogenicity and reactogenicity.

Key findings

  • All three most advanced vaccines encode full-length SARS-CoV-2 Spike with K986P/V987P proline substitutions; BNT162b2 uses 30 μg mRNA two doses 21 days apart, mRNA-1273 uses 100 μg two doses 28 days apart, and CVnCoV uses 12 μg two doses 28 days apart. BNT162b2 and mRNA-1273 use N1-methylpseudouridine-modified mRNA plus dsRNA removal, whereas CVnCoV uses unmodified, sequence-engineered mRNA.
  • Efficacy was high: BNT162b2 showed up to 95% efficacy in phase 3, mRNA-1273 conferred 94.1% protection against symptomatic COVID-19, and real-world Israeli data for BNT162b2 estimated 97% effectiveness against symptomatic/severe disease and 94% against asymptomatic infection.
  • CVnCoV at 12 μg induced neutralizing antibody titers in all participants comparable to convalescent individuals, while BNT162b2 and mRNA-1273 generally surpassed convalescent titers, even in elderly trial groups. BNT162b2 elicited S-specific CD8+ T cell responses in 91.9% of participants, compared with low or undetectable levels for mRNA-1273.
  • Reactogenicity differed: fever after second mRNA-1273 dose occurred in 40% at 100 μg and 57% at 250 μg, but none at 25 μg; BNT162b2 fever after second 30 μg dose was 8% in ages 18–55 and 17% in ages 65–85; CVnCoV fever was reported by 57% after the first dose. Rare anaphylaxis after mRNA-1273 or BNT162b2 was estimated at approximately 1 in 100,000.

Methods

  • Narrative review synthesizing three decades of mRNA vaccine research, innate immune sensing of RNA, lipid nanoparticle delivery, coronavirus Spike antigen design, and (pre)clinical data for BNT162b2, mRNA-1273, and CVnCoV.
  • Compares vaccine composition in Table 1 and discusses design features, immunogenicity, reactogenicity, efficacy, and safety using published preclinical studies, phase 1/2/3 trials, real-world data, and preprints.
  • No new primary data, systematic search strategy, or meta-analysis is described.

Limitations

  • The paper states remaining unknowns: how innate immune responses to mRNA-LNPs affect translation, immunogenicity, and reactogenicity; how long immunity lasts; whether mRNA or the LNP vehicle drives the innate immune signature; and whether further optimization is possible.
  • The paper notes that direct comparisons between vaccine candidates require caution because of differences in test populations, study designs, vaccination approaches, and potential efficacy differences; it also states that no public data exist on the Acuitas LNPs used in CVnCoV and BNT162b2, and that it cannot pinpoint which components cause differential CD8+ T cell responses.
  • Evident from the text: the review relies heavily on early clinical reports, preprints, and manufacturer disclosures, and some LNP ratios and structural elements are described as not yet confirmed for the COVID-19 vaccines.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.jconrel.2021.03.043

Cites

84 of 84 references verified0 citation errors · 0 not checkable

Statistics

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Verification

Claims the paper makes

85 Not checked yet · 20 Own interpretation · 14 Sources not found · 1 Partly supported · 1 No basis given · accuracy not yet measured

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Show all 77 claims

  • It may state two separate claims as one. 38
  • Probably not a substantial claim. 7
44 of 44
  • The paper relies on this without support.

    Two mRNA vaccines were granted authorization for emergency use in less than one year.

    “In less than one year, two mRNA vaccines were granted authorization for emergency use”
  • The paper relies on this without support.

    Neutralizing antibody levels above a certain threshold are protective against SARS-CoV-2.

    “but remained above levels that are expected to be protective”
2 of 2

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Citations

Cites

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Research works printed but not linked: 1

  1. Sahin, 2020, BNT162b2 induces SARS-CoV-2-neutralising antibodies and T cells in humans, medRxiv

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Metadata

Authors
Verbeke, R., Lentacker, I., De Smedt, S. C., & Dewitte, H.
Affiliations
Ghent University (BE)
Venue
Journal of Controlled Release
Publisher
Elsevier BV
Published
2021-05
Volume
333
Pages
511-520
ISSN
0168-3659 (ISSN-L)
OpenAlex
W3143214431
Cited by
504
References
90
Citations by year
2026: 72 · 2025: 72 · 2024: 88 · 2023: 118 · 2022: 94 · 2021: 60
FWCI
28.50
Type
journal article
Language
en
Open access
Locations
  • Journal of Controlled Release (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Ghent University Academic Bibliography (Ghent University) (submittedVersion, other-oa)
Funders
  • Universiteit Gent (F2020/IOF-StarTT/039, FAF-C/2018/1213)
  • Horizon 2020 European Innovation Council Fast Track to Innovation (810685)
  • Horizon 2020
  • FWO (G040319N, G016221N)
  • Kom op tegen kanker
Topics
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › RNA Interference and Gene Delivery
  • Life Sciences › Immunology and Microbiology › Immunology › Immunotherapy and Immune Responses
Keywords
mRNA vaccines, COVID-19 pandemic, SARS-CoV-2 spike protein, lipid nanoparticles, BNT162b2, mRNA-1273, vaccine design, immunogenicity, reactogenicity, emergency use authorization
MeSH terms
COVID-19, SARS-CoV-2, COVID-19 Vaccines, BNT162 Vaccine, Humans, RNA, Messenger, Vaccines, Pandemics

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