Despite the availability of vaccines, there remains a need to identify specific immune responses that correlate with protection against SARS-CoV-2 infection. Additionally, the operational capability of retail pharmacy infrastructure to collect longitudinal data and biological samples needs to be assessed. This study aims to fill these gaps by determining correlates of protection (CoP), assessing the infrastructure's capability, and examining demographic and geographic differences in participation.

This multi-center study will utilize a prospective, longitudinal observational design to assess CoR and CoP for COVID-19 vaccinations. Prior to enrollment in this study, participants will receive a federally licensed and authorized vaccine, manufactured by Pfizer-BioNTech or Moderna, for the prevention of COVID-19. Each participant will complete a pre-screener questionnaire which will collect information to confirm the participant's eligibility. Upon passing the pre-screener, the participant will complete their electronic consent form and will be enrolled in the study within 72 hours of their vaccination with blood collected to establish baseline for humoral immune marker. A subset of total enrollment, a cohort of 80 participants, will also enroll in the PBMC cohort; participants in the PBMC cohort will enroll in the study within 24 hours of their vaccination with blood collected to establish baseline immune marker levels.

During this study, participants will complete five (5) visits on site (Day 01, Day 31, Day 91, Day 181, Day 366), which will involve data collection and a blood draw. Participants enrolled in the PBMC cohort will have an additional blood draw at Day 01, Day 31, Day 181, and Day 366.

All study participants will complete a weekly electronic patient reported outcome (ePRO) to report symptoms of COVID-19, and to report if they have been exposed to anyone who has tested positive for COVID-19.

Participants will be asked to report to the clinic for a nasal swab test (via molecular assay) when: participant has at least one symptom with or without a fever, and/or if the participant has recent exposure or close contact to another person with COVID-19.

This study aims to enroll at least 90 COVID-19 endpoint cases, based on an annual incidence rate of 2.5%.

Inclusion Criteria:

1. People ≥3 years of age at time of enrollment.
2. Willing and able to provide informed consent, or assent in pediatric population, if appropriate, prior to initiation of study procedures.
3. Able to understand and comply with planned study procedures.
4. Available for all study data collection points.
5. Receipt of the most recent FDA-licensed and authorized COVID-19 vaccine (i.e., the 2024-2025 Moderna COVID-19 vaccine or the 2024-2025 Pfizer-BioNTech COVID-19 vaccine which includes the KP.2 strain of the JN.1-lineage vaccine), as recommended by the FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) and outlined in the FDA's updated guidance, administered within 3 days of enrollment.

PBMC cohort only:

People ages ≥18 years at time of enrollment. Available for first blood sample collection within 1 day of vaccine.

Exclusion Criteria:

1. Currently participating or plans to participate in another clinical trial involving an investigational product before completing this study.
2. Planned to receive another COVID-19 vaccine within 180 days.
3. Receipt of COVID-19 vaccination within 180 days prior to current vaccination.
4. Receipt of Shingrix vaccine in the 28 days prior to the COVID-19 vaccination or planned receipt of Shingrix vaccine within 28 days after receipt of COVID-19 vaccination.
5. Self-report of recently confirmed COVID-19 infection within 30 days.
6. Any disease or medical condition that, in the opinion of the principal investigator or sub-investigator, is a contraindication to study participation.

PBMC cohort only:

Confirmed positive urine pregnancy test at study visits per Schedule of Activities.

Prior to enrollment in this study, participants will receive a federally licensed and authorized vaccine, manufactured by Pfizer-BioNTech or Moderna, for the prevention of COVID-19. Each participant will complete a pre-screener questionnaire which will collect information to confirm the participant's eligibility. Upon passing the pre-screener, the participant will complete their electronic consent form and will be enrolled in the study within 72 hours of their vaccination with blood collected to establish baseline for humoral immune marker. A subset of total enrollment, a cohort of 80 participants, will also enroll in the PBMC cohort; participants in the PBMC cohort will enroll in the study within 24 hours of their vaccination with blood collected to establish baseline immune marker levels.