Changes in severity, mortality, and virus genome among a Spanish cohort of patients hospitalized with SARS-CoV-2 oleh Rocío Aznar-Gimeno, J. Ramón Paño-Pardo, Luis M. Esteban, Gorka Labata-Lezaun, M. José Esquillor-Rodrigo, Angel Lanas, David Abadía-Gallego, Francisco Diez-Fuertes, Carlos Tellería-Orriols, Rafael del-Hoyo-Alonso, M. Trinidad Serrano