Assessment of protection against reinfection with SARS-CoV-2 among 4 million PCR-tested individuals in Denmark in 2020: a population-level observational study

od Hansen, Christian Holm, Michlmayr, Daniela, Gubbels, Sophie Madeleine, Mølbak, Kåre, Ethelberg, Steen
izdano v Lancet (2021)