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The Yale Paxlovid for Long COVID (PAX LC) Trial

Thank you for your interest in the Yale Paxlovid for Long COVID (PAX LC) Trial. Enrollment is now closed, and we are not accepting new participants. The trial result should be available later this summer when all the participants finish their follow-up and the data are analyzed.

For further information or inquiries, please get in touch with our study team at

About the Study

This trial investigates the efficacy of a 15-day course of Paxlovid, an antiviral medication authorized by the FDA for acute COVID-19, in improving health outcomes for individuals experiencing long-term effects of COVID-19, also known as Long COVID. The persistence of the SARS-CoV-2 virus post-infection is one suspected cause of Long COVID.

By comparing Paxlovid with a placebo, alongside analyzing blood and saliva samples, we aim to deepen our understanding of the immune response in Long COVID patients and to determine if Paxlovid treatment might be helpful.

Study Criteria

Participants with Long COVID are characterized by symptoms starting within 4 weeks of SARS-CoV-2 infection and persisting for at least 3 months. If you have previously been infected by SARS-CoV-2, experienced symptoms consistent with Long COVID, and meet other listed eligibility criteria, you may have been eligible for this study.

Study Process

Participants are randomly assigned to receive either Paxlovid or a placebo for 15 days. Throughout the study, participants maintain a daily diary, complete periodic surveys, and provide blood and saliva samples for testing. Compensation is provided for time and effort.

Note on Enrollment

The research leveraged Hugo Health's Kindred platform for participant engagement and data sharing, ensuring a partnership approach and efficient data collection.

Additional Information

The study is a collaborative effort among Yale's Center for Infection and Immunity (CII), the Center for Outcomes Research and Evaluation (CORE), and the Center for Clinical Investigation (YCCI), with funding and design input from Pfizer. Dr. Harlan Krumholz, the Principal Investigator, is a co-founder of Hugo Health and his involvement is overseen by Yale University.

For more details, visit the trial's page on or contact us via email.