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).