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CompletedNCT06147063ARTEMIS-CUpdated Aug 31, 2026

A Randomized Trial Evaluating a mRNA-VLP Vaccine's Immunogenicity and Safety for COVID-19

A Phase 1 interventional study of AZD9838 and Licensed SARS-CoV-2 mRNA vaccine in COVID-19 and SARS-CoV-2 Infection, sponsored by AstraZeneca. Completed at 5 sites in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-31.

Sponsored by AstraZeneca · Phase 1, Interventional, and Prevention

From the registry’s dates

  • Primary completion was Apr 2024, 2 years 5 months ago, and no results have been posted to the registry.
Phase
Phase 1
Study type
Interventional
Enrollment
243
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The purpose of this study is to characterize the safety and immunogenicity of AZD9838 and AZD6563 when administered as a single dose vaccination against SARS-CoV-2 in adults.

Read the detailed description

This is a Phase I, open-label, randomized, active-controlled study to assess the safety and immunogenicity of 2 dosages of AZD9838 and 2 dosages of AZD6563 compared with a licensed SARS-CoV-2 mRNA vaccine in approximately 240 healthy participants. AZD6563 will be assessed in adults 18 years of age and older. AZD9838 will be assessed in adults 18 to 64 years of age only.

The duration of each participant's involvement in the study will be approximately 12 months following administration of study vaccination.

02

Conditions studied

  • COVID-19
  • SARS-CoV-2 Infection

Keywords

  • COVID-19
  • Coronavirus
  • Vaccine
  • SARS-CoV-2
  • mRNA vaccine
03

In context

COVID-19

7,640 studies on the registry are indexed under COVID-19; 488 are open to participants now.

This study's enrollment of 243 is above the median of 100 across 4,099 interventional studies indexed under COVID-19.

Browse COVID-19 studies →

Lead sponsor

AstraZeneca is the lead sponsor of 3,429 studies on the registry; 270 are open to participants now.

Of its 357 completed or terminated interventional studies of FDA-regulated products, 173 (48%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Eligibility criteria

Key Inclusion Criteria:

  • Adults ≥ 18 years at the time of signing informed consent.
  • Self-reported History of SARS-CoV-2 infection at least 6 months prior to study vaccination AND/OR prior completion of primary series vaccination against COVID-19, with the final dose received at least 6 months prior to study vaccination
  • Negative SARS-CoV-2 RT-PCR test at Visit 1
  • Body mass index (BMI) of \<35 kg/m2 at screening
  • Medically stable - according to the judgement of the investigator, hospitalization within the study is not anticipated and participant is likely to remain in the study through the end of the protocol specified follow-up.

Key Exclusion Criteria:

  • Acute illness/infection on day prior or day of dosing
  • History of hypersensitivity to any component of the study vaccination, severe adverse reaction associated with a vaccine and/or severe allergic reaction
  • Positive COVID-19 test result within 6 months of Visit 1
  • Receipt of licensed, authorized, or investigational COVID-19 vaccines in the 6 months prior to administration of study intervention or expected receipt through completion of Visit 5.
  • Receipt of any COVID-19 monoclonal antibody (licensed or investigational) within 3 months or receipt of immunoglobulin (non-COVID related) or blood products within 6 months prior to administration of study intervention, or expected receipt during the study
  • Receipt of any licensed or investigational vaccine (other than licensed influenza vaccines or non-study COVID-19 vaccines) within 30 days prior to Visit 1 or expected receipt prior to completion of Visit 4. Licensed influenza vaccines are permitted beginning > 14 days before and > 14 days after administration of study intervention.
  • Previous history of myocarditis or pericarditis
  • Woman who are pregnant, lactating, or of child-bearing potential and not using a contraception or abstinence from at least 4 weeks prior to study vaccination and until at least 6 months after study vaccination
  • Lab values above ULN (Serum creatinine, AST, ALT), below LLN (hemoglobin, WBC, Platelet count) or any lab value that in the opinion of the investigator is clinically significant or might confound analysis of the study results. Participants with laboratory values outside of the normal range may have the abnormal test repeated within the screening window and if the values are normal, then the participant can be randomized. If the repeated value remains outside of the normal range but it is not felt to be clinically significant by the Investigator, the case can be discussed with the AstraZeneca study physician and if they both agree the value is not clinically significant, the participant can be randomized
  • History of malignancy within 5 years (treated non-melanoma skin cancer and locally treated cervical cancers allowed)
  • Known or suspected congenital or acquired immunodeficiency
  • Known or suspected autoimmune conditions as determined by history and /or physical examination
  • Active infection with hepatitis B or C
  • Troponin I levels above the normal range at the screening visit
  • History of hypersensitivity to kanamycin or any aminoglycoside antibiotics (eg, neomycin, streptomycin, tobramycin, and gentamicin).
05

Study design

Phase
Phase 1
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
243 participants (actual)

Study arms

  • Experimental
    AZ BA.4/5 5µg, 18-64 years

    Participants received a single intramuscular dose of AZD9838.

    Biological: AZD9838

  • Experimental
    AZ BA.4/5 10µg, 18-64 years

    Participants received a single intramuscular dose of AZD9838.

    Biological: AZD9838

  • Active comparator
    Pfizer XBB.1.5, 18-64 years

    Participants received a single intramuscular dose of the Pfizer XBB.1.5 vaccine.

    Biological: Licensed SARS-CoV-2 mRNA vaccine

  • Experimental
    AZ XBB.1.5 5µg, 18-64 years

    Participants received a single intramuscular dose of AZD6563.

    Biological: AZD6563

  • Experimental
    AZ XBB.1.5 10µg, 18-64 years

    Participants received a single intramuscular dose of AZD6563.

    Biological: AZD6563

  • Experimental
    AZ XBB.1.5 5µg, >=65 years

    Participants received a single intramuscular dose of AZD6563.

    Biological: AZD6563

  • Experimental
    AZ XBB.1.5 10µg, >=65 years

    Participants received a single intramuscular dose of AZD6563.

    Biological: AZD6563

  • Active comparator
    Pfizer XBB.1.5, >=65 years

    Participants received a single intramuscular dose of the Pfizer XBB.1.5 vaccine.

    Biological: Licensed SARS-CoV-2 mRNA vaccine

Interventions

  • BiologicalAZD9838

    Intramuscular (IM) injection.

  • BiologicalLicensed SARS-CoV-2 mRNA vaccine

    Intramuscular (IM) injection.

  • BiologicalAZD6563

    Intramuscular (IM) injection.

06

What researchers measure

Primary outcomes

  1. Number of participants with immediate unsolicited adverse events (AE)

    Immediate unsolicited AEs were defined as having an onset within 30 minutes post vaccination.

    Time frame: Within 30 minutes post vaccination

  2. Number of participants with injection site and systemic solicited adverse reactions (ARs)

    Injection site solicited ARs included injection site pain, injection site erythema (redness), and injection site swelling. Systemic solicited ARs included fever, chills, headache, myalgia (muscle aches and pains), and fatigue (physical or mental tiredness).

    Time frame: Through 7 days post vaccination

  3. Number of participants with any unsolicited adverse events (AEs)

    Unsolicited AEs were any AEs reported in addition to predefined solicited ARs.

    Time frame: Through 28 days post vaccination

  4. Number of participants with serious adverse events (SAEs), Medically-attended adverse events (MAAEs), and Adverse Events of Special Interest (AESIs)

    An SAE is an AE meeting one or more of: resulted in death; was immediately life-threatening; required or prolonged in-patient hospitalization; resulted in persistent or significant disability/incapacity; was a congenital anomaly/birth defect; or was an important medical event that may have jeopardized the participant or required intervention to prevent the above. MAAEs are AEs leading to medically attended visits that were not routine physical examination or vaccination visits (eg, urgent care, emergency room, or unscheduled visits to/from medical personnel, including telemedicine). An AESI was an event of scientific and medical interest, specific to understanding the safety profile of the investigational vaccine, requiring close monitoring and rapid communication by Investigators to the Sponsor.

    Time frame: Through 12 months post vaccination

  5. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 ancestral strain neutralizing antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 ancestral strain neutralizing antibodies

    Time frame: Day 29

  6. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies

    Time frame: Day 29

  7. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies

    Time frame: Day 29

  8. Geometric mean fold rise (GMFR) for SARS-CoV-2 ancestral strain neutralizing antibodies

    GMFR for SARS-CoV-2 ancestral strain neutralizing antibodies

    Time frame: Day 1 to Day 29

  9. Geometric mean fold rise (GMFR) for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies

    GMFR for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies

    Time frame: Day 1 to Day 29

  10. Geometric mean fold rise (GMFR) for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies

    GMFR for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies

    Time frame: Day 1 to Day 29

  11. Proportion of participants with neutralizing antibody seroresponse against SARS-CoV-2 ancestral strain

    Seroresponse was defined as GMFR \>=4 from baseline

    Time frame: Day 1 to Day 29

  12. Proportion of participants with neutralizing antibody seroresponse against SARS-CoV-2 Omicron BA.4/5

    Seroresponse was defined as GMFR \>=4 from baseline

    Time frame: Day 1 to Day 29

  13. Proportion of participants with neutralizing antibody seroresponse against SARS-CoV-2 Omicron XBB.1.5

    Seroresponse was defined as GMFR \>=4 from baseline

    Time frame: Day 1 to Day 29

Secondary outcomes

  1. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 ancestral strain neutralizing antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 ancestral strain neutralizing antibodies by visit.

    Time frame: Day 1 to Day 360

  2. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies by visit.

    Time frame: Day 1 to Day 360

  3. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies by visit.

    Time frame: Day 1 to Day 360

  4. Geometric mean fold rise (GMFR) for SARS-CoV-2 ancestral strain neutralizing antibodies

    GMFR for SARS-CoV-2 ancestral strain neutralizing antibodies by visit.

    Time frame: Day 1 to Day 360

  5. Geometric mean fold rise (GMFR) for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies

    GMFR for SARS-CoV-2 Omicron BA.4/5 neutralizing antibodies by visit.

    Time frame: Day 1 to Day 360

  6. Geometric mean fold rise (GMFR) for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies

    GMFR for SARS-CoV-2 Omicron XBB.1.5 neutralizing antibodies by visit.

    Time frame: Day 1 to Day 360

  7. Proportion of participants with neutralizing antibody seroresponse against SARS-CoV-2 ancestral strain

    Seroresponse was defined as GMFR \>=4 from baseline by visit.

    Time frame: Day 1 to Day 360

  8. Proportion of participants with neutralizing antibody seroresponse against SARS-CoV-2 Omicron BA.4/5

    Seroresponse was defined as GMFR \>=4 from baseline by visit.

    Time frame: Day 1 to Day 360

  9. Proportion of participants with neutralizing antibody seroresponse against SARS-CoV-2 Omicron XBB.1.5

    Seroresponse was defined as GMFR \>=4 from baseline by visit.

    Time frame: Day 1 to Day 360

  10. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 ancestral strain S protein binding antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 ancestral strain S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  11. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 Beta variant S protein binding antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 Beta variant S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  12. Model-adjusted geometric mean titer (GMT) for SARS-CoV-2 Delta variant S protein binding antibodies

    Model-adjusted GMTs and 95% CIs for SARS-CoV-2 Delta variant S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  13. Geometric mean titer (GMT) for SARS-CoV-2 Omicron subvariant S protein binding antibodies

    GMT for SARS-CoV-2 Omicron subvariant S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  14. Geometric mean fold rise (GMFR) for SARS-CoV-2 ancestral strain S protein binding antibodies

    GMFR for SARS-CoV-2 ancestral strain S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  15. Geometric mean fold rise (GMFR) for SARS-CoV-2 Beta variant S protein binding antibodies

    GMFR for SARS-CoV-2 Beta variant S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  16. Geometric mean fold rise (GMFR) for SARS-CoV-2 Delta variant S protein binding antibodies

    GMFR for SARS-CoV-2 Delta variant S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  17. Geometric mean fold rise (GMFR) for SARS-CoV-2 Omicron subvariant S protein binding antibodies

    GMFR for SARS-CoV-2 Omicron subvariant S protein binding antibodies by visit.

    Time frame: Day 1 to Day 360

  18. Proportion of participants with S protein binding antibody seroresponse against SARS-CoV-2 ancestral strain

    Seroresponse was defined as GMFR \>=4 from baseline by visit.

    Time frame: Day 1 to Day 360

  19. Proportion of participants with S protein binding antibody seroresponse against SARS-CoV-2 Beta variant

    Seroresponse was defined as GMFR \>=4 from baseline by visit.

    Time frame: Day 1 to Day 360

  20. Proportion of participants with S protein binding antibody seroresponse against SARS-CoV-2 Delta variant

    Seroresponse was defined as GMFR \>=4 from baseline by visit.

    Time frame: Day 1 to Day 360

  21. Proportion of participants with S protein binding antibody seroresponse against SARS-CoV-2 Omicron subvariant

    Seroresponse was defined as GMFR \>=4 from baseline by visit.

    Time frame: Day 1 to Day 360

  22. Geometric mean response of S-specific CD4+ T-cells expressing Th1 cytokines

    Geometric mean response of S-specific T cells by phenotype as measured by an intracellular cytokine staining assay over time.

    Time frame: Day 1 to Day 180

  23. Geometric mean response of S-specific CD4+ T-cells expressing Th2 cytokines

    Geometric mean response of S-specific T cells by phenotype as measured by an intracellular cytokine staining assay over time.

    Time frame: Day 1 to Day 180

  24. Geometric mean response of S-specific CD8+ T-cells expressing cytokines

    Geometric mean response of S-specific T cells by phenotype as measured by an intracellular cytokine staining assay over time.

    Time frame: Day 1 to Day 180

  25. Incidence of H. pylori anti-ferritin antibodies

    Incidence of H. pylori anti-ferritin antibodies.

    Time frame: Day 1 to Day 360

  26. Titer of H. pylori anti-ferritin antibodies

    Titer of H. pylori anti-ferritin antibodies.

    Time frame: Day 1 to Day 360

  27. Incidence of human anti-ferritin antibodies (light and/or heavy)

    Incidence of human anti-ferritin antibodies (light and/or heavy).

    Time frame: Day 1 to Day 360

  28. Titer of human anti-ferritin antibodies (light and/or heavy)

    Incidence of human anti-ferritin antibodies (light and/or heavy).

    Time frame: Day 1 to Day 360

07

Study locations

5 sites
  • Research Site
    Long Beach, California 90815, United States
  • Research Site
    Rolling Hills Estates, California 90274, United States
  • Research Site
    Chicago, Illinois 60640, United States
  • Research Site
    Wichita, Kansas 67207, United States
  • Research Site
    North Charleston, South Carolina 29405, United States
08

References and documents

Individual participant data

Plan to share: Yes — Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. "Yes", indicates that AZ are accepting requests for IPD, but this does not mean all requests will be approved.

Supporting information: Study protocol, Sap

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 31, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06147063
Lead sponsor
AstraZeneca
Responsible party
Sponsor
First posted
Nov 27, 2023
Start date
Nov 27, 2023
Primary completion
Apr 30, 2024
Completion
Mar 27, 2025
Last update
Aug 31, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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