Beyond COVID-19: the promise of next-generation coronavirus vaccines

Coronaviruses (CoVs) have caused three global outbreaks: severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) in 2003, Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, and SARS-CoV-2 in 2019, with significant mortality and morbidity. The impact of coronavirus disease 2019 (COVID-19) raised serious concerns about the global preparedness for a pandemic. Furthermore, the changing antigenic landscape of SARS-CoV-2 led to new variants with increased transmissibility and immune evasion. Thus, the development of broad-spectrum vaccines against current and future emerging variants of CoVs will be an essential tool in pandemic preparedness. Distinct phylogenetic features within CoVs complicate and limit the process of generating a pan-CoV vaccine capable of targeting the entire Coronaviridae family. In this review, we aim to provide a detailed overview of the features of CoVs, their phylogeny, current vaccines against various CoVs, the efforts in developing broad-spectrum coronavirus vaccines, and the future.