Pro-inflammatory cytokines, including IL-6, IL-1, tumour necrosis factor (TNF)-a, C-reactive protein, and fibrinogen levels, may directly accelerate frailty by promoting muscle protein degradation [41], and the pro-inflammatory state may lead to overall suppression of the inflammatory response that is needed to fight an acute respiratory infection [42], including acute virus pneumonia such as COVID-19. Here, TNF is linked to COVID-19.