Second, unvaccinated carriers of rare TLR7 variants that predispose to severe COVID-19 could benefit from prophylactic interferon gamma treatment, similar to that given to patients with chronic granulomatous disease to prevent severe infection (The International Chronic Granulomatous Disease Cooperative Study Group, 1991; Marciano et al., 2004). This evidence concerns the gene TLR7 and chronic granulomatous disease.