😷 Medical Mask
🤢 Nauseated
🤮 Vomiting
🤧 Sneezing
🤒 Thermometer
🤕 Bandage
🚑 Ambulance
💊 Pill
💉 Syringe
🦠 Microbe
🧼 Soap
🧽 Sponge
a. It's such a popular emoji; it is being used no more in coronavirus tweets than others
b. People joking or making light of coronavirus news
c. Combination of the above