The aim of the study is to assess the safety, efficacy, and immunogenicity of AZD1222 for the prevention of COVID-19.
The COVID-19 pandemic has caused major disruption to healthcare systems with significant socioeconomic impacts. Currently, there are no specific treatments available against COVID-19 and accelerated vaccine development is urgently needed. A safe and effective vaccine for COVID-19 prevention would have significant public health impact.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
32,450
Number of Participants With Binary Response
A binary response, whereby a participant with negative serostatus at baseline is defined as a COVID-19 case if their first case of SARS-CoV-2 RT-PCR-positive symptomatic illness occurs ≥ 15 days post second dose of study intervention. Otherwise, a participant is not defined as a COVID-19 case. The primary efficacy analysis was performed once approximately 150 events meeting the primary efficacy outcome measure definition had occurred across the AZD1222 and placebo groups.
Time frame: From 15 days post second dose up to data cut-off date (DCO) of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
Number of Participants With Adverse Events (AEs) Post Each Dose of Study Intervention
An AE is the development of any untoward medical occurrence in a clinical study participant administered medicinal product and which does not necessarily have a causal relationship with this medicinal product. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.
Time frame: From Day 1 up to 28 days post second dose of study intervention, approximately 57 days
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
An SAE is an AE occurring during any study phase that fulfils 1 or more of the following criteria: death; immediately life-threatening; in-participant hospitalization or prolongation of existing hospitalization; persistent or significant disability or incapacity; congenital abnormality or birth defect; an important medical event. AESIs were events of scientific and medical interest specific to the further understanding of the study intervention safety profile and required close monitoring and rapid communication by the investigators to the sponsor. MAAEs are defined as AEs leading to medically-attended visits that were not routine visits for physical examination or vaccination, such as an emergency room visit, or an otherwise unscheduled visit to or from medical personnel (medical doctor) for any reason. Different follow-up time between AZD1222 and Placebo groups (20223 versus 3893 participant years).
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Research Site
Phoenix, Arizona, United States
Research Site
Scottsdale, Arizona, United States
Research Site
Little Rock, Arkansas, United States
Research Site
Berkeley, California, United States
Research Site
El Centro, California, United States
Research Site
Los Angeles, California, United States
Research Site
Los Angeles, California, United States
Research Site
San Diego, California, United States
Research Site
San Diego, California, United States
Research Site
San Francisco, California, United States
...and 74 more locations
Time frame: From Day 1 up to receipt of non-study COVID-19 vaccination or a maximum of Day 760 for participants without non-study COVID-19 vaccination.
Number of Participants With Local and Systemic Solicited AEs in the Substudy Only
Solicited AEs are local or systemic predefined events for assessment of reactogenicity. Solicited AEs were collected in a e-Diary only for participants in the substudy.
Time frame: From Day 1 up to 7 days post each dose of study intervention, approximately 14 days
Number of Participants With First Post-intervention Response for SARS-CoV-2 Nucleocapsid Antibodies Post Second Dose of Study Intervention
The incidence of the first post-intervention response (negative at baseline to positive post intervention with study intervention) for SARS-CoV-2 nucleocapsid antibodies occurring ≥ 15 days post second dose of study intervention (key secondary endpoint).
Time frame: From 15 days post second dose up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
Number of Participants With First COVID-19 Symptomatic Illness Using Centers for Disease Control and Prevention (CDC) Criteria Post Second Dose of Study Intervention
The incidence of the first case of SARS-CoV-2 RT-PCR-positive symptomatic illness occurring ≥ 15 days post second dose of study intervention using CDC criteria. Participant must present with at least 1 of the following symptoms per CDC criteria: fever, shortness of breath, difficulty breathing, chills, cough, fatigue, muscle aches, body aches, headache, new loss of taste, new loss of smell, sore throat, congestion, runny nose, nausea, vomiting, or diarrhea.
Time frame: From 15 days post second dose up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
Number of Participants With First COVID-19 Symptomatic Illness Using University of Oxford-Defined Symptom Criteria Post Second Dose of Study Intervention
The incidence of the first case of SARS-CoV-2 RT-PCR-positive symptomatic illness occurring ≥ 15 days post second dose of study intervention using University of Oxford-defined symptom criteria: new onset of fever (\> 100 °Fahrenheit \[\> 37.8 °Celsius\]), cough, shortness of breath, or anosmia/ageusia.
Time frame: From 15 days post second dose up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
Number of Participants With First Symptomatic COVID-19 Regardless of Evidence of Prior SARS-CoV-2 Infection Post Second Dose of Study Intervention
The incidence of the first case of SARS-CoV-2 RT-PCR-positive symptomatic illness occurring ≥ 15 days post second dose of study intervention regardless of evidence of prior SARS-CoV-2 infection (key secondary endpoint).
Time frame: From 15 days post second dose up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
Number of Participants With COVID-19 Severe or Critical Symptomatic Illness Post Second Dose of Study Intervention
The incidence of SARS-CoV-2 RT-PCR-positive severe or critical symptomatic illness occurring ≥ 15 days post second dose of study intervention. The severity of COVID-19 was evaluated in participants with symptoms of COVID-19. Following are the findings regarding severe of critical symptomatic COVID-19: clinical signs at rest indicative of severe systemic illness; respiratory failure; evidence of shock; significant acute renal, hepatic, or neurologic dysfunction; admission to an intensive care unit; and death (key secondary endpoint).
Time frame: From 15 days post second dose up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
Number of Participants With COVID-19 Severe or Critical Symptomatic Illness Post First Dose of Study Intervention
The incidence of SARS-CoV-2 RT-PCR-positive severe or critical symptomatic illness occurring post first dose of study intervention. The severity of COVID-19 was evaluated in participants with symptoms of COVID-19. Following are the findings regarding severe of critical symptomatic COVID-19: clinical signs at rest indicative of severe systemic illness; respiratory failure; evidence of shock; significant acute renal, hepatic, or neurologic dysfunction; admission to an intensive care unit; and death.
Time frame: From 15 days post second dose up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
Number of Participants With COVID-19-Related Emergency Department Visits Post Second Dose of Study Intervention
The incidence of COVID-19-related emergency department visits occurring ≥ 15 days post second dose of study intervention (key secondary endpoint).
Time frame: From 15 days post second dose up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of 17 weeks
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
The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titer/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titer, where 'n' is the number of participants with titer information.
Time frame: Baseline (Day 1) and Days 15, 29, 43, 57, 90, 180, 360, and 730
Geometric Mean Fold Rise (GMFR) for SARS-CoV-2 S and RBD Antibodies as Measured by MSD Serology Assay
The fold rise was calculated as the ratio of the post-vaccination titer level to the pre-vaccination titer level. GMFR was calculated as anti-logarithm of Σ (log base 2 transformed (post-vaccination titer/ pre-vaccination titer)/n). Where 'n' is the number of participants with titer information.
Time frame: Days 15, 29, 43, 57, 90, 180, 360, and 730
Percentage of Participants With Seroresponse to the S and RBD Antigens of AZD1222 as Measured by MSD Serology Assay
The fold rise was calculated as the ratio of the post-vaccination titer level to the pre-vaccination titer level. The percentage of participants with a post-intervention seroresponse (≥ 4-fold rise in titers from baseline value to 28 days post each dose) to the S and RBD antigens of AZD1222 as measured by MSD serology assay is reported.
Time frame: Days 15, 29, 43, 57, 90, 180, 360, and 730
GMTs for SARS-CoV-2 Neutralizing Antibodies as Measured by Pseudo-neutralization Assay
The GMT was calculated as the antilogarithm of Σ(log base 2 transformed titer/n), i.e. as the anti-logarithm transformation of the mean of the log-transformed titer, where 'n' is the number of participants with titer information.
Time frame: Baseline (Day 1) and Days 15, 29, 43, 57, 90, 180, and 360
GMFR for SARS-CoV-2 Neutralizing Antibodies as Measured by Pseudo-neutralization Assay
The fold rise was calculated as the ratio of the post-vaccination titer level to the pre-vaccination titer level. GMFR was calculated as anti-logarithm of Σ (log base 2 transformed (post-vaccination titer/ pre-vaccination titer)/n). Where 'n' is the number of participants with titer information.
Time frame: Days 15, 29, 43, 57, 90, 180, and 360
Percentage of Participants With Seroresponse to SARS-CoV-2 Neutralizing Antibodies of AZD1222 as Measured by Pseudo-neutralization Assay
The fold rise was calculated as the ratio of the post-vaccination titer level to the pre-vaccination titer level. The percentage of participants with a post-intervention seroresponse (≥ 4-fold rise in titers from baseline value to 28 days post each dose) to SARS-CoV-2 neutralizing antibodies of AZD1222 as measured by pseudo-neutralization assay is reported.
Time frame: Days 15, 29, 43, 57, 90, 180, and 360
Number of Participants With COVID-19 Symptomatic Illness Post First Dose of Study Intervention
The incidence of SARS-CoV-2 RT-PCR-positive symptomatic illness occurring post first dose of study intervention.
Time frame: From Day 1 up to DCO of 05 March 2021 or study discontinuation or unblinding or receipt of non-study COVID-19 vaccination, up to a maximum of approximately 27 weeks