Structural mimics of SARS-CoV-2

Since its first detection in 2019, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has infected approximately 778 million people and claimed 7.1 million lives globally. A deeper understanding of the biology of SARS-CoV-2 was instrumental in facilitating the development of protective vaccines and new therapeutics, as well as evaluating the impact of drug re-purposing to limit the pandemic. To date, approximately 13.64 billion vaccine doses have been administered; with approximately 67% of the global population having completed their primary series of COVID-19 vaccinations. The FDA has authorised the use of several repurposed drugs to combat the disease and while these developments have been instrumental in curbing the pandemic, the approved therapies have shown poor efficacy in cases of severe disease. Furthermore, several vaccine candidates received FDA approval following clinical trials where they proved to be both safe and efficacious. These vaccines were sanctioned for emergency roll-out to the global population, conferring herd immunity and reducing both infections and related mortalities. However, these vaccines are not without flaws and are limited by short term immune responses and poor efficacy against emerging variants, which has resulted in slip-through infections. Hence, efforts to develop potent drugs and vaccines are continuing. In these efforts, physiologically relevant models of SARS-CoV-2 infection are critical. This review describes available SARS-CoV-2 particle mimics, their contribution to COVID-19 research and the development of new vaccines and therapies.