Phase 4
N=1,188
The Efficacy of the 2023-2024 Updated COVID-19 Vaccines Against COVID-19 Infection
COVID-19 · Vaccine-Preventable Diseases · SARS CoV 2 Infection · Upper Respiratory Tract Infection · Upper Respiratory Disease
Bottom Line
View on ClinicalTrials.gov: NCT06065176 ↗Enrolled (actual)
1,188
Serious AEs
0.5%
Results posted
Nov 2025
Primary outcome: Primary: Number of Symptomatic SARS-CoV-2 Infections Between Randomized, Study-vaccinated Participants and the Comparator Group — 48; 94 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 4
- Interventions
- Novavax COVID-19 vaccine (2023-2024 formula XBB containing) (Biological); Pfizer COVID-19 mRNA vaccine (2023-2024 formula XBB containing) (Biological)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- Sarang K. Yoon, DO, MOH
- Primary completion
- Sep 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Number of Symptomatic SARS-CoV-2 Infections Between Randomized, Study-vaccinated Participants and the Comparator Group |
48; 94 | — |
| SECONDARY Number of Symptomatic SARS-CoV-2 Infections Between the Protein Subunit and mRNA Vaccine Groups. |
52; 42 | — |
Summary
The purpose of this research study is to find out how well two different 2023-2024 updated COVID-19 vaccines protect people from COVID-19 (the disease caused by the SARS-CoV-2 virus), and to determine if getting a 2023-2024 updated vaccine provides better protection from COVID-19 than not getting a vaccine.
If the participant chooses to get a 2023-2024 updated COVID-19 vaccine as part of this study, they will have a 50/50 chance of receiving either the Novavax or Pfizer mRNA vaccine.
If the participant decides not to get a 2023-2024 updated COVID-19 vaccine, the participant can still participate in other study activities.
STUDY ACTIVITIES:
* An online enrollment survey
* An in-person enrollment visit
* Weekly online surveys for 20 weeks
* Weekly COVID-19 tests for 20 weeks
* Additional online surveys if you have COVID-19 symptoms or tested positive for COVID-19.
* Additional COVID-19 tests if you have COVID-19 symptoms or tested positive.
* Online survey questions in the middle and at the end of the study
Eligibility Criteria
Inclusion Criteria
- Age ≥18 years
- Previously received ≥ 2-doses of US FDA-authorized mRNA vaccines
- Comfortable reading and responding to text messages and emails sent in English or having an interpreter assist them
- Plan to remain in the greater Salt Lake City area for the next 12 months
- Daily access to the internet (via cell phone, laptop, desktop, or tablet) and a phone with text messaging capabilities
- Willingness to complete weekly symptom and illness surveillance surveys sent via text and email
- Willingness to complete an online survey at enrollment, mid-study, and end-of-study surveys
- Willingness to be contacted periodically by study staff via text, email, and/or telephone as part of study activities
- Willingness to self-collect rapid antigen tests (RAT; approved by FDA EUA for COVID-19 detection) weekly and when prompted for study purposes, and to send results via the study portal
- Willingness to self-collect additional rapid antigen test (approved by FDA EUA for COVID-19 detection) if experiencing a qualifying symptomatic illness or upon RAT-confirmation of an asymptomatic infection
- Willingness to attend in-person visit to receive supply of rapid antigen tests and training on their use (all participants) and to receive a COVID-19 booster (if in randomized group)
Exclusion Criteria
- Lives with another person who is already enrolled in this study as reported by the subject on the Eligibility Survey (Appendix C. Eligibility Survey)
- Previous hypersensitivity reaction to the study vaccines as reported by the subject on the Eligibility Survey (Appendix C. Eligibility Survey)
- Recent infection [Real time Reverse Transcription Polymerase Chain Reaction assay (RT-PCR) and/or RAT confirmed infection ≤ 90 days of trial vaccine administration
- Receipt of a COVID-19 vaccine within ≤ 90 days of trial vaccine administration
- Participation in other vaccine trials
- Medical history of immunosuppression
- Receipt of J&J vaccine prior to study enrollment
- Receipt of any investigational prevention therapies for SARS-CoV-2 infections, such as prophylactic antiviral medications or other immune system modifying interventions within ≤ 90 days of trial vaccine administration
- Unwillingness to provide electronic consent
- Unwillingness to self-report occupation, work responsibilities, and prior COVID-19 illness.
Data sourced from ClinicalTrials.gov (NCT06065176). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.