A Narrative Review of COVID-19 Vaccines

Abstract

The COVID-19 pandemic has shaken the world since early 2020 and its health, social, economic, and societal negative impacts at the global scale have been catastrophic. Since the early days of the pandemic, development of safe and effective vaccines was judged to be the best possible tool to minimize the effects of this pandemic. Drastic public health measures were put into place to stop the spread of the virus, with the hope that vaccines would be available soon. Thanks to the extraordinary commitments of many organizations and individuals from around the globe and the collaborative effort of many international scientists, vaccines against COVID-19 received regulatory approval for emergency human use in many jurisdictions in less than a year after the identification of the viral sequence. Several of these vaccines have been in use for some time; however, the pandemic is still ongoing and likely to persist for the foreseeable future. This is due to many reasons including reduced compliance with public health restrictions, limited vaccine manufacturing/distribution capacity, high rates of vaccine hesitancy, and the emergence of new variants with the capacity to spread more easily and to evade current vaccines. Here we discuss the discovery and availability of COVID-19 vaccines and evolving issues around mass vaccination programs.

Keywords: COVID-19; COVID-19 vaccines; SARS-CoV-2; vaccination; vaccine hesitancy.

Figure 3

Schematic summary of the four broad groups of COVID-19 vaccines with examples of current COVID-19 vaccines. (Redrawn by the authors based on second figure in Ref. [60]).

Figure 1

Schematic drawing of SARS-CoV-2 representing the major virus components: spike glycoprotein (S), hemagglutinin-esterase dimer (HE), membrane protein (M), envelope protein (E), nucleocapsid, and genomic RNA. (Redrawn by the authors based on Figure 2 in Ref. [13]).

Figure 2

SARS CoV-2 life cycle: (1) Binding and viral entry to the host cell via endocytosis; (2) release of viral genome; (3) translation and (4) replication of RNA genome; (5) transcription and translation of RNA into protein; (6) assembly and budding, followed by (7) mature virion formation; and (8) release of the new virion from the host cell. (Redrawn by the authors based on second figure in Ref. [22]).