COV-COMPARE Immunogenicity of vaccine VLA2001 compared to AZD1222.

A randomized, observer-blind, controlled, superioty study to compare the immunogenicity against Covid-19, of VLA2001 vaccine to AZD1222 vaccine, in adults.

In follow-up

Aim of the study

The purpose of this study is to compare the study drug, called VLA2001 with the licensed vaccine AZD1222 from Astra Zeneca in terms of safety and measures of the immune response against COVID-19 disease. Unlike some other vaccine trials where people receive trial vaccine or a placebo injection, everyone in this study will receive a COVID-19 vaccine and the main outcome being measured is the immune response, not the occurrence of disease, alongside rates of any common side effects.


Inclusion and exclusion criteria

Inclusion Criteria


1. Participants must have read, understood, and signed the informed consent form (ICF).

2. Participants of either gender aged 18 years and older at screening.

3. 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.

§  A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 3 months prior to the expected day of randomization (visit 1).

4. Must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days after each vaccination.

5. Women of childbearing potential (WOCBP) must be able and willing to use at least 1 highly effective method of contraception (i.e. include hysterectomy, bilateral salpingectomy, and bilateral oophorectomy, hormonal oral [in combination with male condoms with spermicide], transdermal, implant, or injection, barrier [i.e. condom, diaphragm with spermicide]; intrauterine device; vasectomized partner [6 months minimum], clinically sterile partner; or abstinence) for a minimum of 3 months after the last dose of study vaccine.

§  A female participant is considered to be a WOCBP after menarche and until she is in a postmenopausal state for 12 consecutive months (without an alternative medical cause) or otherwise permanently sterile. Note: Participants not of childbearing potential are not required to use any other forms of contraception during the study. Non-childbearing potential is defined as participant confirmed:

§  Surgical sterilization (e.g., bilateral oophorectomy, bilateral salpingectomy, bilateral occlusion by cautery, hysterectomy, or tubal ligation).

§  Postmenopausal (defined as permanent cessation of menstruation for at least 12 consecutive months prior to screening).

6. WOCBPs must have a negative pregnancy test prior to each vaccination.


Exclusion Criteria

Participants will not be eligible for the study if they meet any of the exclusion criteria, or will be discontinued from study vaccination if they develop any of the following exclusion criteria during the study.

  1. Participant is pregnant or planning to become pregnant within 3 months after study vaccine administration.
  2. History of allergy to any component of the vaccine.
  3. Significant infection (e.g. positive SARS-CoV-2 RT-PCR) or other acute illness, including fever > 100 °F (> 37.8 °C) 48 hours before vaccination.
  4. Participant has a known or suspected defect of the immune system, such as participants with congenital or acquired immunodeficiency,

including infection with HIV, status post organ transplantation or immuno-suppressive therapy within 4 weeks prior to the expected day of randomization (Visit 1).

  • Immuno-suppressive therapy is defined as administration of chronic (longer than 14 days) prednisone or equivalent ≥ 0.05 mg/kg/day within 4 weeks prior to the expected day of randomization (visit 1), radiation therapy or immunosuppressive cytotoxic drugs/ monoclonal antibodies in the previous 3 years; topical and inhaled steroids are allowed.
  • Participants with chronic HIV unless: HIV disease with documented viral load <50 copies/ml and CD4 count >200 cells/mm3 for at least 6 months before enrolment, and stable antiretroviral therapy for the last 6 months
  1. Participant has a history of cerebral venous sinus thrombosis, heparin-induced thrombocytopenia or antiphospholipid syndrome.
  2. Participant has a history of malignancy in the past 5 years other than squamous cell or basal cell skin cancer. If there has been surgical excision or treatment more than 5 years ago that is considered to have achieved a cure, the participant may be enrolled. A history of hematologic malignancy is a permanent exclusion. Participants with a history of skin cancer must not be vaccinated at the previous tumour site.
  3. History of drug dependency or current use of drug of abuse or alcohol abuse at screening.
  4. Significant blood loss (> 450 mL) or has donated 1 or more units of blood or plasma within 6 weeks prior to the expected day of randomization (Visit 1).
  5. History of clinically significant bleeding disorder (e.g., factor deficiency, coagulopathy, or platelet disorder), or prior history of significant bleeding or bruising following IM injections or venepuncture.
  6. Severe and uncontrolled ongoing autoimmune or inflammatory disease History of Guillain-Barre syndrome or any other demyelinating condition.
  7. Any other significant disease, disorder or finding which in the opinion of the investigator may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study.


Prior/concomitant therapy:

  1. Receipt of immunoglobulin or another blood product within the 3 months before expected day of randomization (visit 1) in this study or those who expect to receive immunoglobulin or another blood product during this study.
  2. Receipt of medications and or vaccinations intended to prevent COVID-19.
  3. Receipt of any vaccine (licensed or investigational), other than licensed influenza vaccine, within 28 days prior to the expected day of randomization (Visit 1).



  1. Any member of the study team or sponsor.
  2. An immediate family member or household member of the study’s personnel.


What participating in the study involves?

Receiving an immunisation of either VLA2001 or registered AstraZeneca on visit 1 and a second at the Day 29 appointment, 4 weeks apart. Subsequent follow-up appointments on Day 43, Day 71, Day 208 and Day 365, involving certain clinical examinations such as venepuncture.

Additional visits or procedures may be performed at the discretion of the investigators, e.g., further medical history and physical examination, or additional blood tests and other investigations if clinically relevant

Results (if applicable)