Petrone D, Mateo-Urdiales A, Sacco C, Riccardo F, et al. Reduction of the risk of severe COVID-19 due to Omicron compared to Delta variant in Italy (November 2021 - February 2022). Int J Infect Dis 2023 Jan 25:S1201-9712(23)00027.
PMID: 36708869