Study suggests mRNA SARS-CoV-2 vaccines remain effective against variants The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused over four million deaths and infected over 194 million worldwide. In an effort to counter the rapid spread of the virus, which has an unpredictable propensity to cause severe or even fatal disease in a significant minority of cases, vaccines were developed at an unprecedentedly rapid rate. Background The emergence of several SARS-CoV-2 variants that are associated with higher transmissibility and sometimes greater virulence than the wildtype SARS-CoV-2 strain has challenged the assumption that successful global vaccination can be the sole solution for combatting this virus. In fact, many of these variants have been declared variants of concern (VOCs), as they resist neutralization by antibodies directed against the virus following either natural infection or vaccination.