As part of their original EUA requests, both ModernaTX Inc. and Pfizer Inc. submitted plans to continue to monitor the safety of the vaccines as they are used under EUA. These plans for monitoring the overall safety of the vaccines and ensuring that any safety concerns are identified and evaluated in a timely manner, and which include monitoring for myocarditis and pericarditis, have been updated to include the newly authorized populations. In addition, longer-term safety follow-up is ongoing for participants enrolled in the clinical trials for both vaccines. Furthermore, the FDA and the CDC have several systems in place to continually monitor COVID-19 vaccine safety and allow for the timely detection and investigation of potential safety concerns.