CRP and swine influenza: C-reactive protein (CRP), a marker of inflammation, is significantly elevated in various respiratory virus infections, such as H7N9 and H1N1 influenza, and correlates with the severity observed in COVID-19, as well as in diseases caused by other coronaviruses like Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and the original SARS-CoV [6].