Table 1.

Characteristics of the main variants detected during the COVID‐19 pandemic

Variants	Origin	tMRCA	Transmissibility	Clinical severity	Clinical response to vaccines
Alpha	UK	2020‐11‐25	Higher than previous variants	Possibly similar incidence of severe COVID‐19 and death	Vaccines prevent infection and adverse events
Beta	South Africa	2020‐11‐24	Higher than previous variants	Possibly similar incidence of severe COVID‐19 and death	Vaccines prevent infection and adverse events (possibly less effective in preventing infection)
Gamma	Brazil	2020‐12‐21	Higher than previous variants	Possibly similar incidence of severe COVID‐19 and death	Vaccines prevent infection and adverse events (possibly less effective in preventing infection)
Delta	India	2020‐09‐20	Much higher than previous variants	Increased incidence of severe COVID‐19 and death	Vaccines prevent infection and adverse events (slightly lower efficacy in preventing infection)
Omicron	South Africa	2021‐01‐25	Extremely higher than previous variants	Lower incidence of severe COVID‐19 and death	Preliminary data suggest that vaccines prevent infection and adverse events (possible lower efficacy vs. other VOCs)

Abbreviations: tMRCA, time to the most recent common ancestorp; UK, United Kingdom; VOCs, variants of concern.