Phase II/III Study of AZD2816, for the Prevention of COVID-19 in Adults (AZD2816)
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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT04973449 |
Recruitment Status :
Completed
First Posted : July 22, 2021
Last Update Posted : January 18, 2023
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Condition or disease | Intervention/treatment | Phase |
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COVID-19 SARS-CoV-2 | Biological: AZD1222 Biological: AZD2816 | Phase 2 Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 2848 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Previously vaccinated individuals will receive 1 dose of AZD1222 or AZD2816 on Day 1. Previously unvaccinated participants will receive one of the following 2-dose vaccinations:
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Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Masking Description: | Double Blind: two or more parties are unaware of the intervention assignment. |
Primary Purpose: | Prevention |
Official Title: | A Phase II/III Partially Double-Blinded, Randomised, Multinational, Active-Controlled Study in Adults to Determine the Safety and Immunogenicity of AZD2816, a Vaccine for the Prevention of COVID-19 |
Actual Study Start Date : | June 27, 2021 |
Actual Primary Completion Date : | February 4, 2022 |
Actual Study Completion Date : | August 2, 2022 |

Arm | Intervention/treatment |
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ChAdOx1-S booster: one dose of AZD1222
Previously vaccinated with AZD1222, dosing on day 1
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Biological: AZD1222
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6. |
ChAdOx1-S booster: one dose of AZD2816
Previously vaccinated with AZD1222, dosing on day 1
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Biological: AZD2816
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6 |
mRNA booster: one dose of AZD1222
Previously vaccinated with an mRNA vaccine, dosing on day 1
|
Biological: AZD1222
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6. |
mRNA booster: one dose of AZD2816
Previously vaccinated with an mRNA vaccine, dosing on day 1
|
Biological: AZD2816
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6 |
2 doses of AZD1222, 4 weeks apart
Previously unvaccinated. First dose day 1, second dose day 29
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Biological: AZD1222
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6. |
2 doses of AZD2816, 4 weeks apart
Previously unvaccinated. First dose day 1, second dose day 29
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Biological: AZD2816
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6 |
2 doses of AZD2816, 12 weeks apart
Previously unvaccinated. First dose day 1, second dose day 85
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Biological: AZD2816
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6 |
one dose of AZD1222 + one dose AZD2816, 4 weeks apart
Previously unvaccinated. Dose of AZD1222 on day 1, dose of AZD2816 on day 29
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Biological: AZD1222
10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6. Biological: AZD2816 10 mM histidine/histidine hydrochloride, 7.5% (w/v) sucrose, 35 mM sodium chloride, 1 mM magnesium chloride, 0.1% (w/v) polysorbate 80, 0.1 mM edetate disodium, 0.5% (w/v) ethanol, at pH 6.6 |
- The safety and tolerability of 1 dose of AZD2816 in the previously vaccinated cohort with AZD1222 [ Time Frame: for 7 days ]Incidence of local and systemic solicited AEs
- The safety and tolerability of 1 dose of AZD2816 in the previously vaccinated cohort with AZD1222 [ Time Frame: 28 days post dose ]
The change from baseline for safety laboratory measures
Incidence of unsolicited AEs, including MAAEs, SAEs, and AESIs,
- The safety and tolerability of a 2-dose primary vaccination with AZD2816 in the unvaccinated cohort [ Time Frame: for 7 days ]Incidence of local and systemic solicited AEs
- The safety and tolerability of a 2-dose primary vaccination with AZD2816 in the unvaccinated cohort [ Time Frame: 28 days post dose ]
The change from baseline for safety laboratory measures
Incidence of unsolicited AEs, including MAAEs, SAEs, and AESIs
- To determine if the response against B.1.351 elicited by an AZD2816 booster dose in participants previously vaccinated with AZD1222 is non-inferior to the response against Wuhan-Hu-1 strain elicited by 2-dose AZD1222 administered to naïve participants [ Time Frame: 28 days post second dose ]GMT ratio of pseudoneutralizing antibodies for AZD2816 booster/AZD1222 vaccination
- To determine if the response against the B.1.351 variant elicited by a 2-dose AZD2816 vaccination is non-inferior to the response against the original Wuhan-Hu-1 strain elicited by a 2-dose AZD1222 vaccination in the unvaccinated cohort [ Time Frame: 28 days post second dose ]GMT ratio of pseudoneutralizing antibodies for AZD2816 vaccination/AZD1222 Vaccination
- To determine if seroresponse against the B.1.351 variant elicited by a 2-dose AZD2816 vaccination is non-inferior to seroresponse against the original WuHan-hu-1 strain elicited by a 2-dose AZD1222 vaccination in the unvaccinated cohort [ Time Frame: 28 days post second dose ]Difference in seroresponse rates
- To determine if the neutralizing antibody GMT response against the B.1.351 variant elicited by a 2-dose AZD2816 vaccination is non-inferior to the response elicited by a 2-dose AZD1222 vaccination in the unvaccinated cohort [ Time Frame: 28 days post second dose ]GMT ratio of pseudoneutralizing antibodies
- To determine if the response against the B.1.351 variant elicited by AZD1222 + AZD2816 vaccination is non-inferior to the response against the Wuhan-Hu-1 strain elicited by AZD1222 in the unvaccinated cohort [ Time Frame: 28 days post second dose ]GMT ratio of pseudoneutralizing antibodies
- To determine if the neutralizing antibody GMT response against the original Wuhan-Hu-1 elicited by a 2-dose AZD2816 vaccination is non-inferior to the response elicited by a 2-dose AZD1222 vaccination [ Time Frame: 28 days post second dose ]GMT ratio of pseudoneutralizing antibodies
- To determine if the response against B.1.351 elicited by an AZD2816 booster dose in participants previously vaccinated with AZD1222 is non-inferior to the response elicited by 2-dose AZD1222 vaccination administered to vaccination naïve participants [ Time Frame: 28 days post second dose ]
GMT ratio of pseudoneutralizing antibodies
Difference in seroresponse rates
- To determine if the humoral immune response elicited against the B.1.351 variant by an AZD2816 booster dose is non-inferior to the response elicited by an AZD1222 booster dose in participants previously vaccinated with AZD1222 [ Time Frame: 28 days post second dose ]
GMT ratio of pseudoneutralizing antibodies
Difference in seroresponse rates
- To determine if the response against the WuHan-hu-1 strain elicited by an AZD2816 booster in participants previously vaccinated with AZD1222 is non-inferior to the response elicited by 2-dose AZD1222 administered to vaccination naïve participants [ Time Frame: 28 days post second dose ]
GMT ratio of pseudoneutralizing antibodies
Difference in seroresponse rates
- To determine if the humoral immune response against the original WuHan-hu-1 strain elicited by an AZD1222 booster dose in participants previously vaccinated with AZD1222 is non-inferior to the response elicited by a 2-dose AZD1222 vaccination [ Time Frame: 28 days post second dose ]
GMT ratio of pseudoneutralizing antibodies
Difference in seroresponse rates
- To determine if the humoral immune response against the original WuHan-hu-1 strain elicited by an AZD2816 booster dose is non-inferior to the response elicited by an AZD1222 booster dose in participants previously vaccinated with AZD1222 [ Time Frame: 28 days post second dose ]GMT ratio of pseudoneutralizing antibodies

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 115 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
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Adult, ≥ 18 years of age at the time of consent
For inclusion in the SARS-CoV-2 seronegative population:
- No history of laboratory-confirmed SARS-CoV-2 infection (ie, no positive nucleic acid amplification test and no positive antibody test).
- Seronegative for SARS-CoV-2 at screening (lateral flow test to detect reactivity to the nucleoprotein).
- Medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up
- Able to understand and comply with study requirements/procedures (if applicable, with assistance by caregiver, surrogate, or legally authorized representative) based on the assessment of the investigator
- Signed informed consent obtained before conducting any study-related procedures
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Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
Previously COVID-19 Vaccinated Participants:
- Prior completion of a 2-dose primary homologous vaccination regimen against SARSCoV-2 with either AZD1222 (2 standard doses as authorized vaccine or as investigational product in a clinical trial with a 4 to 12-week dosing interval) or with an mRNA vaccine approved for emergency or conditional use. The second dose in all cases should have been administered at least 3 months prior to first administration of study intervention.
Exclusion Criteria:
- History of allergy to any component of AZD1222/AZD2816.
- History of Guillain-Barré syndrome, any demyelinating disease, or any other neuroimmunologic condition
- Significant infection or other acute illness, including fever > 100 °F (> 37.8 °C) on the day prior to or day of randomization
- Any confirmed or suspected immunosuppressive or immunodeficient state, including asplenia or HIV/AIDS.
- Recurrent severe infections and use of immunosuppressant medication within the past 6 months (≥ 20 mg per day of prednisone or its equivalent, given daily or on alternate days for ≥ 15 days within 30 days prior to administration of study intervention). The following exceptions are permitted: Topical/inhaled steroids or short-term oral steroids (course lasting ≤ 14 days)
- History of primary malignancy (see protocol)
- History of thrombocytopenia and/or thrombosis, including participants who have experienced major venous and/or arterial thrombosis in combination with thrombocytopenia following vaccination with any COVID-19 vaccine
- History of heparin-induced thrombocytopenia, congenital thrombophilia (ie, factor V Leiden, prothrombin G20210A, antithrombin III deficiency, protein C deficiency and protein S deficiency, factor XIII mutation, familial dysfibrinogenemia), auto-immune thrombophilia (antiphospholipid syndrome, anti-cardiolipin antibodies, anti-β2- glycoprotein 1 antibodies), or paroxysmal nocturnal haemoglobinuria.
- Clinically significant bleeding (eg, factor deficiency, coagulopathy, or platelet disorder), or prior history of significant bleeding or bruising following intramuscular injections or venepuncture
- Severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder, or neurological illness, as judged by the Investigator
- Any other significant disease, disorder, or finding that may significantly increase the risk to the participant because of participation in the study, affect the ability of the participant to participate in the study, or impair interpretation of the study data
- Any autoimmune conditions, except mild psoriasis and vitiligo.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04973449
Brazil | |
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Brasilia, Brazil, 70200-730 | |
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Curitiba, Brazil, 80810-050 | |
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Natal, Brazil, 59020-035 | |
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Natal, Brazil, 59025-050 | |
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Porto Alegre, Brazil, 90035-903 | |
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Salvador, Brazil, 40110-060 | |
Poland | |
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Lublin, Poland, 20-362 | |
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Oświęcim, Poland, 32-600 | |
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Puławy, Poland, 24-100 | |
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Zamosc, Poland, 22-400 | |
South Africa | |
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Bloemfontein, South Africa, 9301 | |
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Cape Town, South Africa, 7500 | |
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Johannesburg, South Africa, 1818 | |
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Johannesburg, South Africa, 2013 | |
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Johannesburg, South Africa, 2092 | |
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Somerset West, South Africa, 7130 | |
United Kingdom | |
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Birmingham, United Kingdom, B15 2TH | |
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Bournemouth, United Kingdom, BH7 7DW | |
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Bristol, United Kingdom, BS105NB | |
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Bristol, United Kingdom, BS2 8BJ | |
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Edinburgh, United Kingdom, EH16 4SA | |
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Harrow, United Kingdom, HA1 3UJ | |
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Hull, United Kingdom, HU3 2KZ | |
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London, United Kingdom, E2 0HL | |
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London, United Kingdom, NW1 2BH | |
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London, United Kingdom, SE1 9RT | |
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London, United Kingdom, SE5 9NU | |
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Manchester, United Kingdom, M8 5RB | |
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Newcastle-upon-Tyne, United Kingdom, NE1 4LP | |
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Nottingham, United Kingdom, NG7 2QW | |
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Oxford, United Kingdom, OX3 7EJ | |
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Plymouth, United Kingdom, PL6 8DH | |
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Portsmouth, United Kingdom, PO1 3HN | |
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Sheffield, United Kingdom, S5 7AU | |
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Truro, United Kingdom, TR1 3LJ |
Responsible Party: | AstraZeneca |
ClinicalTrials.gov Identifier: | NCT04973449 |
Other Study ID Numbers: |
D7220C00001 |
First Posted: | July 22, 2021 Key Record Dates |
Last Update Posted: | January 18, 2023 |
Last Verified: | January 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure |
Supporting Materials: |
Study Protocol Statistical Analysis Plan (SAP) |
Time Frame: | AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure |
Access Criteria: | When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure URL: https://astrazenecagroup-dt.pharmacm.com/DT/Home |
URL: | https://astrazenecagroup-dt.pharmacm.com/DT/Home |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
COVID-19 Vaccine |
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