Please call or visit your healthcare provider if you have concerns about your health. If your symptoms are life-threatening, go to the emergency room or call 911. The reporting of harmful side effects should be done through the Vaccine Adverse Event Reporting System (VAERS): https://vaers.hhs.gov/esub/index.jsp.
You can also make a report using the V-safe After Vaccination Health Checker tool on your smartphone: https://vsafe.cdc.gov/. If you sign up, this tool will check in on you after you get vaccinated. You can also report side effects directly to Moderna at 1-866-663-3762 or Pfizer at 800-438-1985.