We first searched for monoallelic and biallelic non-synonymous IFNAR1 variants in our Human Genetics of Infectious Diseases (HGID) cohort of 19,489 individuals with various viral diseases, including, but not restricted to HSE, critical COVID-19 and influenza pneumonia, and adverse reactions to LAV (https://www.hgid.org). Here, IFNAR1 is linked to viral load.