COVID-19 Adult Booster Vaccine Study – Phase II/III

Delayed Heterologous SARS-CoV-2 Vaccine Dosing (Boost) After Receipt of EUA Vaccines

Protocol Description

The primary purpose of this multi-center research program is to study the safety of various vaccine combinations and determine which provide the greatest protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and variants that cause COVID-19.

Study Level: Phase II/III

Eligibility Criteria

Subject to certain exclusion criteria, this study is enrolling participants, ages 18 and older, who were fully vaccinated using one of the three vaccinations approved in the U.S. under the Food and Drug Administration’s emergency use authorization (EUA): the Moderna, Pfizer/BioNTech, and Janssen Pharmaceuticals/Johnson & Johnson vaccines. A second group in this study will include adults who have not previously received the vaccination.
Males and Females: Ages 18 and older


Participants in the first study group will be given a single dose of a COVID vaccine within 12 to 20 weeks after they received the last dose of their EUA vaccine. The second study group will receive the 2-dose Moderna vaccine and will receive a booster 12 to 20 weeks after their second injection. All participants in the study will be followed for 12 months after receiving their vaccine boost and will provide blood samples that researchers will use to study their immune response against the new variants of COVID-19.
Visits: About 6 for Group 1 and about 9 for Group 2
Duration: About a year

Status: Open to Enrollment

Source(s) of Support

National Institute of Allergy and Infectious Diseases

Primary Investigator

Judith Martin, MD

Contact Information

For more information about the study or enrollment, please contact:
The Pittsburgh Vaccine Trials Unit