Serological response to mRNA SARS-CoV-2 BNT162b2 vaccine in kidney transplant recipients depends on prior exposure to SARS-CoV-2.

Grupper et al. have reported on a positive humoral response post full vaccination with mRNA SARS-CoV2 BNT162b2 in only 51/136 (37.5%) kidney transplant recipients (KTRs) without prior exposure to the virus1 . We have conducted an IRB-approved (B707201215598-2021/80) prospective small sample-size study comparing the humoral response to BNT162b2 in 40 consecutive individuals early exposed to the Belgian vaccination program, including 20 KTRs with (n=10, COVID-19(+)) versus without (n=10, COVID-19(-)) history of exposure to SARS-CoV-2 and 20 controls including 10 COVID-19(+) versus 10 COVID-19(-).