The Centers for Disease Control and Prevention is now saying most coronavirus infections are spread by people who don't have symptoms.
The agency published the updated guidance on its website Friday.
According to the CDC, 24% of spread is from asymptomatic people.
About a third is from those who are pre-symptomatic, and 41% is from people experiencing COVID-19 symptoms, CNN reported.
RELATED: CDC updates Thanksgiving guidance, recommends that Americans do not travel
The CDC says asymptomatic spread is why wearing masks is so important.
The CDC also adjusted its guidance Thursday to recommend that Americans do not travel for the Thanksgiving holiday next week, due to surging COVID-19 cases in many parts of the country.
The agency recommends that Americans celebrate the holiday at home with the people they live with, as gathering with family and friends from outside of the household can increase the chances of getting or spreading COVID-19 or the flu.
CDC coronavirus update: Agency says most COVID-19 infections spread by people without symptoms