Currently, 4 Covid-19 vaccines are approved in the European Union but the supply of vaccines depends on many factors. If due to unforeseen circumstances a particular brand of Covid-19 vaccine is not sufficiently supplied, this could mean a significant delay in the national vaccination campaign. Therefore, this study will investigate the effect on the immune response if the interval between 2 vaccine doses is extended, if another brand of COVID-19 vaccine is used for the 2nd dose (booster) or if half the recommended dose is used. In addition, this study will also investigate whether an injection into the skin (intradermal) with a lower dose can produce a similar immune response as an injection into the muscle of the upper arm (intramuscular) with a normal dose.
For this study, 3 Covid-19 vaccines currently on the market will be used, no placebo will be administered.These vaccines are:
- BNT162b2 (Comirnaty®; Pfizer-BioNTech)
- mRNA-1273 Vaccine (COVID-19 Vaccine Moderna®; Moderna)
- COVID-19 Vaccine (ChAdOx1-S [recombinant]) (Vaxzevria®; AstraZeneca)
There are 3 blocks in this study, each containing multiple study groups. In total, there are 12 study groups. In each block, one group will receive the recommended administration schedule of a particular Covid-19 vaccine. The other groups will receive a different administration schedule: lower dose, different booster vaccine, longer interval between doses or intradermal injection.
Title |
Assessment of the immunogenicity and safety of marketed vaccines for COVID-19 after regular schedule and adapted vaccine schedules and routes: Comirnaty® (Pfizer), Covid-19 vaccine Moderna® (Moderna) and Vaxzevria® (AstraZeneca) - IMCOVAS |
Participants (P) |
healthy adults 18-55y |
Intervention (I) |
12 arms in total:
1 prime dose and 1 boost dose. In case of a standard dose, boost dose can be of a different brand than prime dose or longer schedule between two doses . Route: IM or ID |
Control (C) |
Reference schedule of the 3 marketed vaccines BNT162b2 (Comirnaty®;Pfizer-BioNTech): 30 mcg (IM) mRNA-1273 Vaccine (COVID-19 Vaccine Moderna®; Moderna): 100mcg (IM) COVID-19 Vaccine (ChAdOx1-S [recombinant]) (Vaxzevria®, AstraZeneca): 0.5mL (IM) |
Outcome (O) |
Geometric Mean Titre of antibodies binding to the Receptor Binding Domain of SARS-CoV-2 S protein 28 days post last vaccine dose |
Trial Design |
A prospective, post marketing, randomized multicentre interventional study |
Sample Size |
840 healthy volunteers |
Trial duration |
19 months |
Budget |
€2.9 MIO |
Sponsor |
University of Antwerpen |
Chief Investigator |
Dr Katie Steenackers |
External partners |
Institute of Tropical Medecine |
Number of participating sites |
4 |
Participating investigators |
Dr Katie Steenackers (CEV – UA) |