COVID-19 vaccines: what do we know so far?

Paraminder Dhillon, Daniel Altmann, Victoria Male, Paraminder Dhillon, Daniel Altmann, Victoria Male

Abstract

When the novel coronavirus was described in late 2019, it could not have been imagined that within a year, more than 100 vaccine candidates would be in preclinical development and several would be in clinical trials and even approved for use. The scale of the COVID-19 outbreak pushed the scientific community, working in collaboration with pharmaceutical companies, public health bodies, policymakers, funders and governments, to develop vaccines against SARS-CoV-2 at record-breaking speed. As well as driving major amendments to the usual timeframe for bringing a vaccine to fruition, the pandemic has accelerated the development of next-generation technologies for vaccinology, giving rise to two frontrunner RNA vaccines. Although none of the critical safety and efficacy steps have been skipped within the compressed schedules, and the technologies underpinning the novel vaccines have been refined by scientists over many years, a significant proportion of the global population is sceptical of the benefits of COVID-19 vaccines and wary of potential risks. In this interview-based article, we give an overview of how the vaccines were developed and how they work to generate a robust immune response against COVID-19, as well as addressing common questions relating to safety and efficacy.

Conflict of interest statement

Danny Altmann receives remuneration as a Consultant to Oxford Immunotec Ltd. The authors have no other conflicts of interest to declare.

© 2021 Federation of European Biochemical Societies.

Figures

Fig. 1
Fig. 1
Timeline of key events in the early development of leading COVID‐19 vaccines. Milestones in the early stages of the pandemic and development of prominent COVID‐19 vaccines are summarised, with a focus on key collaborations, the initiation and completion of trials, release of trial data and authorisation of vaccine candidates that occurred between January and December 2020. Details on preclinical development and landmark manufacturing and funding agreements are not provided here, and readers are referred to The New York Times Coronavirus Vaccine Tracker for a more comprehensive and up‐to‐date overview.
Fig. 2
Fig. 2
Mechanism of action of mRNA and viral vector vaccines for SARS‐CoV‐2. The basic mechanisms through which COVID‐19 vaccines that use the mRNA platform (shown in blue, top) and the adenoviral vector platform (shown in green, bottom) elicit a robust and long‐lasting immune response against SARS‐CoV‐2 infection are demonstrated. Both platforms involve the delivery of synthetic nucleic acid (mRNA or DNA) that leads to production of the viral antigen, spike protein, inside cells. A key advantage over vaccines involving inactivated virus or recombinant proteins is that cell‐mediated immunity is triggered as well as humoral (antibody‐mediated) immunity, providing high efficacy (Table 1).

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