TNF and inflammatory bowel disease: This is particularly relevant, since patients with IBD such as Crohn's disease (CD) and ulcerative colitis (UC) frequently receive immunosuppressive therapies including antibodies blocking TNF (e.g., infliximab and adalimumab), IL-12 and IL-23 (ustekimumab) as well as integrins such as vedolizumab,13 which might interfere both with the establishment of proper acute anti-viral immune responses as well as with the formation of long-term immunological memory responses against SARS-CoV-2.