LMM and the Antwerp Biobank in new VACCELERATE publication on paediatric COVID-19 vaccination
The VACCELERATE consortium has published the results of the CoVacc trial in Vaccine, a phase 2 randomised study comparing a single-dose versus two-dose primary vaccination schedule of the BNT162b2 mRNA vaccine in previously infected children aged 5 to 11. LMM's Katherine Loens is a co-author on the paper.
The trial tested whether, in children already primed by natural infection, one vaccine dose could work as well as two while causing fewer side effects. Recruitment ran from May 2022 to January 2024, but the study was stopped early due to rapidly declining interest in COVID-19 vaccination among eligible children, with only 31 of the planned 200 participants enrolled. Despite this, both schedules produced strong, long-lasting neutralising antibody responses that remained well above baseline at 12 months, and the vaccine was well tolerated in both groups. Formal non-inferiority of the single dose could not be demonstrated, but the results support the idea that a first dose can act immunologically as a booster in previously infected children.
LMM's role: safeguarding the samples
Blood and saliva samples collected throughout the trial were stored at the study's central biobank in Antwerp. Katherine Loens coordinated this process, ensuring the material was preserved to a standardised quality and remained usable for the immunological analyses behind the paper. This builds on LMM's broader role within VACCELERATE, highlighted previously on this website, where the lab helped design standardised sampling kits and procedures across several VACCELERATE trials, including CoVacc. Even when a trial ends early, well-managed samples keep it scientifically valuable.
Reference: Prat-Aymerich C, Yeghiazaryan L, Pathirana RD, Katherine Loens, et al. A prematurely terminated phase 2, randomised trial to evaluate immunogenicity and reactogenicity of a single versus two-dose primary vaccination regimen of the mRNA vaccine BNT162b2 in previously SARS-CoV-2 infected children 5–11 years old (CoVacc trial). Vaccine. 2026;88:128769.