Humoral and cellular immunogenicity of a fourth dose BNT162b2 in children with chronic kidney diseases.

BACKGROUND

Children with chronic kidney disease (CKD) are at risk of severe complications after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and are recommended to receive vaccine boosters. Although coronavirus disease 2019 (COVID-19) boosters are effective in providing immune responses among healthy children, data on the use of a fourth dose among children with CKD are limited.

METHODS

We prospectively investigated the immunogenicity and safety of a fourth dose of BNT162b2 in children with CKD. Dosages were 0.1 mL and 0.3 mL for children aged 5-11 years and 11-18 years, respectively. Humoral and cellular immunogenicity was assessed at pre-dose 4, and at 1 and 6 months post-dose 4.

RESULTS

Twenty-one children, with a median age of 14.0 years, were included for evaluation. A fourth dose of BNT162b2 elicited significant increases in humoral spike receptor-binding domain immunoglobulin G levels and T-cell responses. Antibody responses were significantly lower among kidney transplant recipients or children receiving calcineurin inhibitors than other CKD children at 1 month post-dose 4. Breakthrough COVID-19 occurred in three children after the fourth dose, and one was hospitalized. One child developed mild gross hematuria 1 day after the fourth dose, which spontaneously resolved. The overall safety profile was acceptable.

CONCLUSIONS

A fourth dose of BNT162b2 was immunogenic and safe in children with CKD.