Thousands of people have been unable to work or perform daily activities, or required care from a health care professional, after getting the new COVID-19 vaccine, according to new data from the Centers for Disease Control and Prevention (CDC).

As of Dec. 18, 3,150 people reported what the agency terms “health impact events” after getting vaccinated.

Those who are experiencing these “events” are “unable to perform normal daily activities, unable to work,” or “required care from [a] doctor or health care professional.”

The incidents were reported through V-safe, a smartphone application. The tool uses text messages and web surveys to provide personalized health check-ins, and allows users to quickly tell the CDC if they’re experiencing side effects.

The CDC and Pfizer, which produces the vaccine with BioNTech, didn’t immediately respond to request for comments.

The information was presented on Dec. 19 by Dr. Thomas Clark, a CDC epidemiologist, to the Advisory Committee on Immunization Practices, an independent panel that provides recommendations to the agency.