Table 1.

Infection Severity, Criticality, and Fatality of the Alpha and Beta Variants in the Population of Qatar

Groups	Infection Severitya	Assessment of Severity, Criticality, and Fatality of the Alpha Variant Compared With the Wild-type Variants Circulating Between 18 January and 15 February 2021b			Assessment of Severity, Criticality, and Fatality of the Beta Variant Compared With the Alpha Variant Between 8 March and 31 May 2021c
		Infection With an Alpha Variant	Infection With a Wild-type Variant	Odds Ratio (95% CI)	Infection With a Beta Variant	Infection With an Alpha Variant	Odds Ratio (95% CI)
Cases	Severe disease	188	279	1.48 (1.18–1.84)	2036	483	1.24 (1.11–1.39)
Controls	Asymptomatic or mild infection	431	944		5806	1707
Cases	Critical disease	21	37	1.58 (.79–3.10)	382	81	1.49 (1.13–1.97)
Controls	Asymptomatic or mild infection	49	125		1056	333
Cases	Severe or critical disease	209	316	1.45 (1.18–1.79)	2418	564	1.28 (1.15–1.42)
Controls	Asymptomatic or mild infection	480	1054		6764	2019
Cases	COVID-19–related death	2	9	.83 (.07–5.58)	142	37	1.57 (1.03–2.43)
Controls	Asymptomatic or mild infection	7	26		381	156

Cases and controls were matched on a ratio of 1:3 by 10-year age group, sex, and biweekly interval of the PCR diagnosis date.

Abbreviations: CI, confidence interval; COVID-19, coronavirus disease 2019; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Severe disease, critical disease, and COVID-19–related death were defined based on the World Health Organization criteria for classifying SARS-CoV-2 infection severity [7] and COVID-19–related death [8].

From 18 January to 15 February 2021, the Alpha variant and other wild-type variants dominated incidence, with limited presence of the Beta variant [2–5].

From 8 March to 31 May 2021, the Beta and Alpha variants dominated incidence, with limited presence of other variants [2–6].