A Phase 2, Comparative Randomised Trial to Evaluate the impact of reduced COVID-19 mRNA vaccination regimen on immunological responses and reactogenicity in paediatric subjects with prior SARS-CoV-2 immunity (CoVacc)

Data from the CoVacc trial, a randomised two-arm trial comparing the two-dose COVID-19 vaccination regimen to a one-dose COVID-19 vaccination regimen in children 5-11 years of age with primed immunity in terms of immunogenicity (neutralizing antibodies & anti-RBD) and safety during (AEs) during a 12 month follow-up. A total of 31 subjects were included. Both single and two dose regimens induced robust and longlasting (up to 12 months) neutralizing and anti-RBD immune
responses, but non-inferiority of the single dose regimen could not be demonstrated. Both regimens also induced longlasting neutralizing responses to different VOCs, but titers were generally lower compared to SARS-CoV-2 wild-type. No new safety concerns were identified based on the safety analysis.

The data are sensitive since they involve personal information of patients. There are also restrictions on use by commercial parties, and on sharing openly based on (inter)national laws and regulations and written informed consent. Therefore these data (and additional clinical data) are only available upon signing a Data Sharing Agreement (see Terms of Access) and within a specially designed environment provided by the UMC Utrecht.