Cross-immunity against SARS-COV-2 variants of concern in naturally infected critically ill COVID-19 patients oleh Douglas D. Fraser, Maitray A. Patel, Logan R. Van Nynatten, Claudio Martin, Shannon L. Seney, Michael R. Miller, Mark Daley, Marat Slessarev, Gediminas Cepinskas, Ganeem K. Juneja, Vanessa Sabourin, Alison Fox-Robichaud, Calvin H. Yeh, Paul Y. Kim, Sigrun Badrnya, Susanne Oehler, Markus Miholits, Brian Webb