School of Medicine to host clinical trials on COVID vaccine boosters

The Pitt School of Medicine, through the Pittsburgh Vaccine Trials Unit, is one of 12 sites across the country selected to participate in a National Institute of Allergy and Infectious Diseases clinical trial in which fully vaccinated adults will receive a third “booster” dose of a COVID-19 vaccine.

The trial will study the safety and immune response of a mixed-booster regimen. 

“As more and more COVID-19 variants are identified, we need to figure out how we, as a community, can stay protected,” said Judy Martin, professor of pediatrics and member of Pitt’s Center for Vaccine Research. “The study’s design is not to show whether we need booster shots. Its focus is identifying which vaccine combinations are safe and provide the most protection against the virus that causes COVID-19 and its variants.”

The study is broken up into two cohorts:

  • One group of about 150 fully vaccinated adults will receive one of the three COVID-19 vaccines available in the U.S. — Johnson & Johnson, Moderna and Pfizer — then 12 to 20 weeks later they will receive a single booster dose of the Moderna vaccine.

  • Another group of around 250 adults who have not received a COVID-19 vaccine will receive the two-dose Moderna COVID-19 vaccine regimen and will receive a booster dose of a vaccine about 12 to 20 weeks later. 

Throughout the year, the volunteer participants will provide blood samples, which will be used to study their immune response against new variants of COVID-19. If participants contract COVID-19 throughout the duration of the study, investigators will assess whether a COVID-19 variant caused the infection.

While study participants will be followed for a year, initial results are expected in late summer 2021.  

For more information on the Pittsburgh site of the trial, visit