• Participation in COVID-19 prophylactic drug trials for the duration of the study (Participation in COVID-19 treatment trials is allowed in the event of hospitalisation due to COVID-19. The study team should be informed as soon as possible)
• Participation in SARS-CoV-2 serological surveys where participants are informed of their serostatus for the duration of the study
• Planned receipt of any vaccine (licensed or investigational), other than the study intervention, within 30 days before and after study vaccination
• Prior receipt of an investigational or licensed vaccine likely to impact on interpretation of the trial data (e.g. Adenovirus vectored vaccines, any coronavirus vaccines)
• Administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccine candidate
• Any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) of immunosuppressant medication within the past 6 months except topical steroids or short-term oral steroids (course lasting ≤14 days)
• History of allergic disease or reactions likely to be exacerbated by any component of ChAdOx1 nCoV-19 or MenACWY or paracetamol
• Any history of angioedema
• Any history of anaphylaxis
• Pregnancy, lactation or willingness/intention to become pregnant during the study
• Current diagnosis of or treatment for cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ)
• History of serious psychiatric condition likely to affect participation in the study
• Bleeding disorder (e.g. factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following IM injections or venepuncture
• Suspected or known current alcohol or drug dependency
• Severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder and neurological illness (mild/moderate well-controlled comorbidities are allowed)
• History of laboratory-confirmed COVID-19
• Seropositive for SARS-CoV-2 antibodies before enrolment
• New onset of fever or a cough or shortness of breath or anosmia/ageusia since February 2020, unless seronegative for SARS-CoV-2 antibodies at screening
• Continuous use of anticoagulants, such as coumarins and related anticoagulants (i.e. warfarin) or novel oral anticoagulants (i.e. apixaban, rivaroxaban, dabigatran and edoxaban)
• Any other significant disease, disorder or finding which 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 data

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes, when the trial is complete
Data accessibility: Anonymised participant data will be made available when the trial is complete, upon requests directed to the corresponding author (Merryn Voysey, merryn.voysey@paediatrics.ox.ac.uk). Proposals will be reviewed and approved by the sponsor, investigator, and collaborators on the basis of scientific merit. After approval of a proposal, data can be shared through a secure online platform after signing a data access agreement. All data will be made available for a minimum of 5 years from the end of the trial.