Humoral and cellular immune response to SARS-CoV-2 mRNA BNT162b2 vaccine in pediatric kidney transplant recipients compared with dialysis patients and healthy children

Abstract

Background Compared with the general population, the immune response to COVID-19 mRNA vaccines is lower in adult kidney transplant recipients (KTRs). However, data is limited for pediatric KTRs. In this study, we aimed to assess humoral and cellular immune responses to the COVID-19 mRNA vaccine in pediatric KTRs. Methods This multicenter, prospective, case-control study included 63 KTRs (37 male, aged 12-21 years), 19 dialysis patients, and 19 controls. Humoral (anti-SARS-CoV2 IgG, neutralizing Ab (nAb)) and cellular (interferon-gamma release assay (IGRA)) immune responses were assessed at least one month after two doses of BNT162b2 mRNA vaccine. Results Among COVID-19 naïve KTRs (n = 46), 76.1% tested positive for anti-SARS-CoV-2 IgG, 54.3% for nAb, and 63% for IGRA. Serum levels of anti-SARS-CoV-2 IgG and nAb activity were significantly lower in KTRs compared to dialysis and control groups (p < 0.05 for all). Seropositivity in KTRs was independently associated with shorter transplant duration (p = 0.005), and higher eGFR (p = 0.007). IGRA titer was significantly lower than dialysis patients (p = 0.009). Twenty (43.4%) KTRs were positive for all immune parameters. Only four of 11 seronegative KTRs were IGRA-positive. COVID-19 recovered KTRs had significantly higher anti-SARS-CoV-2 IgG and nAb activity levels than COVID-19 naïve KTRs (p = 0.018 and p = 0.007, respectively). Conclusions The humoral and cellular immune responses to SARS-CoV-2 mRNA BNT162b2 vaccine are lower in pediatric KTRs compared to dialysis patients. Further prospective studies are required to demonstrate the clinical efficacy of the mRNA vaccine in KTRs. This prospective study was registered in ClinicalTrials.gov (NCT05465863, registered retrospectively at 20.07.2022).

Coronavirus disease 2019 vaccine in pediatric post‐kidney transplantation

“…Unlike for the adult transplant population 45,54–56 adding a third dose for the pediatric kidney transplant recipients may not be necessary to improve seroconversion rates (i.e., S antibody titer). Despite the limitation of the small sample size, it is noteworthy that the seroconversion after a two‐dose series was significantly better in younger age groups than that in the adult population, supporting the argument that pediatric SOT recipients can mount a more robust measured antibody response to vaccination than adult patients, as is consistent with prior reports 21,42,57,58 …”

“…Previous studies have shown that children who received the Pfizer vaccine are less likely to have severe COVID‐19 18–23 . Like adults, children can also have adverse reactions from the COVID‐19 vaccines, including sore arms, muscle aches, fever, and chills.…”

“…The available safety data 18–23 to support emergency use authorization in adolescents aged < 12 years comprise 2260 individuals aged 12–15 years enrolled in a randomized, placebo‐controlled clinical trial in the United States. In this analysis, the measured antibody response of adolescents was non‐inferior to the measured antibody response of the older participants.…”

“…17 Previous studies have shown that children who received the Pfizer vaccine are less likely to have severe COVID-19. [18][19][20][21][22][23] Like adults, children can also have adverse reactions from the COVID-19 vaccines, including sore arms, muscle aches, fever, and chills. Most adverse reactions are mild and may last 1-2 days, and symptoms can be managed with acetaminophen.…”

“…Moreover, patients vaccinated before transplantation may have reduced protection after transplantation, mainly if therapies that reduce B-cell function (e.g., rituximab) are utilized. [28][29][30][31][32][33][34][35] The available safety data [18][19][20][21][22][23] severe disease and prolonged admission and late recovery. [37][38][39][40][41][42] Hence, the benefits of vaccination outweigh any theoretical risks, especially in countries where SARS-CoV-2 transmission continues at a high level.…”