What is the difference between flu (influenza) and COVID-19?

• If a person has COVID-19, they may be contagious for a longer time than if they have the flu. 
• People with the flu are most contagious in the first 3 to 4 days after their illness begins. Some may infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Young children and people with weakened immune systems may infect others for an even longer time.
• Although COVID-19 is still being studied, it is possible for people to spread the virus for about 2 days before symptoms appear. People remain contagious for at least 10 days. If someone shows no symptoms or their symptoms go away, they may also remain contagious for at least 10 days after testing positive for COVID-19.

COVID-19 and the flu can both cause severe illness and may lead to hospitalization. COVID-19 can cause more serious illnesses in some people compared to seasonal influenza (flu). Please visit the CDC for more information on the difference between influenza (flu) and COVID-19.