CD8-based vaccine approaches have been shown to be particularly protective against intranasal viral transmission,42 suggesting that nasal protection through CD8 vaccination may be relevant to SARS-CoV-2 transmission based on recent reports of ACE2 and TMPRSS2 co-expression in nasal epithelium7 and clinical reports of SARS-CoV-2 infection in the olfactory bulb and symptoms of anosmia.43 Here, TMPRSS2 is linked to Kallmann syndrome.