The following is a summary of “Comparison of the Risk of Hospitalization and Severe Disease Among Co-circulating Severe Acute Respiratory Syndrome Coronavirus 2 Variants,” published in the February 2023 issue of Infectious Diseases by Sanmartín, et al.

Between January 2021 and May 2022 in Navarra, Spain, researchers sought to assess the risk of coronavirus disease 2019 (COVID-19) outcomes among co-circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subtypes.

They examined the co-circulating variations’ in rates of hospitalization and serious illness (intensive care unit admission or death) caused by COVID-19. Non-variants of concern (non-VOCs), Alpha, Delta, Omicron BA.1, and Omicron BA.2 were the variations that were examined. Logistic regression models were utilized to determine the adjusted odds ratio (aOR).

Compared to non-VOCs, the Alpha version had a greater risk of hospitalization (aOR, 1.86 [95% CI, 1.28–2.71]) and serious illness (aOR, 2.40 [95% CI, 1.31–4.40]). In comparison to the Alpha variation, the Delta variant did not exhibit a statistically different risk of hospitalization (aOR, 0.73 [95% CI, .40–1.30]) or severe illness (aOR, 3.04 [95% CI, .57–16.22]). Both hazards were considerably decreased by the Omicron BA.1 when compared to the Delta variation (aORs, 0.28 [95% CI, .16–.47] and 0.23 [95% CI, .12–.46], respectively). In comparison to the Omicron BA.1, the BA.2 lowered the risk of hospitalization (aOR, 0.52 [95% CI, .29–.95]).

The Omicron BA.1 and BA.2 significantly reduced the likelihood of severe illness and hospitalization seen with the Alpha and Delta versions. Variant surveillance resulted in significant severity disparities.

Reference: academic.oup.com/jid/article/227/3/332/6706607