Phase 3
Completed N=32,450
Phase III Double-blind, Placebo-controlled Study of AZD1222 for the Prevention of COVID-19 in Adults
Source: ClinicalTrials.gov NCT04516746 ↗Enrolled (actual)
32,450
Serious AEs
4.7%
Results posted
Apr 2022
Primary outcomePrimary: Number of Participants With Binary Response — 73; 130 Participants — p=<0.001
◆ Published Evidence
Established
23citations · ~8 / year
AZD1222-induced nasal antibody responses are shaped by prior SARS-CoV-2 infection and correlate with virologic outcomes in breakthrough infection.
Summary
The aim of the study is to assess the safety, efficacy, and immunogenicity of AZD1222 for the prevention of COVID-19.
Linked Publications (5)
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AZD1222-induced nasal antibody responses are shaped by prior SARS-CoV-2 infection and correlate with virologic outcomes in breakthrough infection.
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Robust humoral and cellular recall responses to AZD1222 attenuate breakthrough SARS-CoV-2 infection compared to unvaccinated.
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Association Between SARS-CoV-2 Viral Load and COVID-19 Vaccination in 4 Phase 3 Trials.
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Modifiers of COVID-19 vaccine efficacy: Results from four COVID-19 prevention network efficacy trials.
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Estimating vaccine efficacy during open-label follow-up of COVID-19 vaccine trials based on population-level surveillance data.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Number of Participants With Binary Response |
73; 130 | <0.001 sig |
| PRIMARY Number of Participants With Adverse Events (AEs) Post Each Dose of Study Intervention |
5736; 1926; 5074; 1797; 8771; 3201 | — |
| PRIMARY Number of Participants With Serious Adverse Events (SAE), Medically Attended Adverse Events (MAAE), and Adverse Event of Special Interest (AESI) Prior to Non-study COVID-19 Vaccination |
621; 136; 4750; 1256; 2516; 591 | — |
| PRIMARY Number of Participants With Local and Systemic Solicited AEs in the Substudy Only |
1250; 173; 977; 120; 1440; 239 | — |
| SECONDARY Number of Participants With First Post-intervention Response for SARS-CoV-2 Nucleocapsid Antibodies Post Second Dose of Study Intervention |
156; 202 | <0.001 sig |
| SECONDARY Number of Participants With First COVID-19 Symptomatic Illness Using Centers for Disease Control and Prevention (CDC) Criteria Post Second Dose of Study Intervention |
95; 145 | <0.001 sig |
| SECONDARY Number of Participants With First COVID-19 Symptomatic Illness Using University of Oxford-Defined Symptom Criteria Post Second Dose of Study Intervention |
86; 136 | <0.001 sig |
| SECONDARY Number of Participants With First Symptomatic COVID-19 Regardless of Evidence of Prior SARS-CoV-2 Infection Post Second Dose of Study Intervention |
76; 135 | <0.001 sig |
| SECONDARY Number of Participants With COVID-19 Severe or Critical Symptomatic Illness Post Second Dose of Study Intervention |
0; 8 | <0.001 sig |
| SECONDARY Number of Participants With COVID-19 Severe or Critical Symptomatic Illness Post First Dose of Study Intervention |
5; 16 | <0.001 sig |
| SECONDARY Number of Participants With COVID-19-Related Emergency Department Visits Post Second Dose of Study Intervention |
1; 9 | 0.005 sig |
| SECONDARY Geometric Mean Titers (GMTs) for SARS-CoV-2 Spike (S) and Receptor Binding Domain (RBD) Antibodies as Measured by Meso Scale Discovery (MSD) Serology Assay |
53.18; 54.68; 1820.10; 53.47; 5782.09; 53.64 | — |
| SECONDARY Geometric Mean Fold Rise (GMFR) for SARS-CoV-2 S and RBD Antibodies as Measured by MSD Serology Assay |
34.28; 0.97; 108.35; 0.92; 455.38; 1.08 | — |
| SECONDARY Percentage of Participants With Seroresponse to the S and RBD Antigens of AZD1222 as Measured by MSD Serology Assay |
89.8; 1.1; 97.1; 1.6; 99.4; 2.5 | — |
| SECONDARY GMTs for SARS-CoV-2 Neutralizing Antibodies as Measured by Pseudo-neutralization Assay |
20.6; 21.4; 41.7; 21.7; 65.9; 23.0 | — |
| SECONDARY GMFR for SARS-CoV-2 Neutralizing Antibodies as Measured by Pseudo-neutralization Assay |
2.03; 1.01; 3.24; 1.07; 10.91; 1.05 | — |
| SECONDARY Percentage of Participants With Seroresponse to SARS-CoV-2 Neutralizing Antibodies of AZD1222 as Measured by Pseudo-neutralization Assay |
24.8; 0.3; 41.1; 1.8; 84.4; 1.9 | — |
| SECONDARY Number of Participants With COVID-19 Symptomatic Illness Post First Dose of Study Intervention |
287; 303 | — |
Eligibility Criteria
Inclusion Criteria
- Increased risk of SARS-CoV-2 infection
- Medically stable
Exclusion Criteria
- confirmed or suspected immunosuppressive or immunodeficient state
- significant disease, disorder, or finding
- Prior or concomitant vaccine therapy for COVID-19
Data sourced from ClinicalTrials.gov (NCT04516746) and the linked publication. 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. Informational only — not medical advice.