There is crossover among the responses of different IFNs, yet this dominant IFN-γ response is noteworthy in this context as prior infection exposures, including malaria, have been shown to induce augmented IFN-γ response17, specifically through epigenetic changes, termed trained immunity18, and IFN-γ, enhanced by prior Bacille Calmette-Guérin (BCG) exposure, has been implicated in clearance of SARS-CoV-2 infection48. Here, IFNG is linked to COVID-19.