BNT162b2 COVID-19 Vaccines in Children, Adolescents and Young Adults with Cancer—A 1-Year Follow-Up

Abstract

(1) Background: Children and young adults with cancer are poorly represented in COVID-19 vaccination studies, and long-term protection conferred by vaccination is not known. (2) Objectives: 1. To determine the adverse effects associated with BNT162B2 vaccination in children and young adults with cancer. 2. To assess its efficacy in stimulating immunological response and in preventing severe COVID-19 disease. (3) Methods: Retrospective single-center study evaluating patients aged 8 to 22 years, with cancer, who underwent vaccination from January 2021 to June 2022. ELISA serologies and serum neutralization were collected monthly from the first injection. Serologies below 26 were considered negative, while those above 264 BAU/mL were considered positive and indicative of protection. Antibodies titers were considered positive above 20. Data on adverse events and infections were collected. (4) Results: 38 patients were included (M/F = 1.7, median age 16 years), of whom 63% had a localized tumor and 76% were undergoing treatment at the time of the first vaccination. Two or three vaccine injections were administered in 90% of patients. Adverse events were mainly systemic and not severe, except for seven grade 3 toxicities. Four cancer-related deaths were reported. Median serology was negative the month following the first vaccination and became protective during the third month. At 3 and 12 months, median serology was 1778 and 6437 BAU/mL, respectively. Serum neutralization was positive in 97% of the patients. COVID-19 infection occurred despite vaccination in 18%; all were mild forms. (5) Conclusions: In children and young adults with cancer, vaccination was well tolerated and conferred effective serum neutralization. COVID-19 infections were mild, and vaccine seroconversion persisted after 12 months in most patients. The value of additional vaccination should be further established.

Pediatric cancer patients vaccinated against SARS-CoV-2—a clinical and laboratory follow-up

“…Our results are novel, as data on immune responses to SARS-CoV-2 vaccinations in pediatric immunocompromised patients are scarce, in particular, regarding data on long-term follow-up [ 5 – 7 ]. Corroborating our results reported previously [ 6 ], one retrospective study reported on good efficacy of SARS-CoV-2 vaccination in 13 patients (median age 17 years) receiving chemotherapy for a solid tumor [ 7 ].…”

“…Corroborating our results reported previously [ 6 ], one retrospective study reported on good efficacy of SARS-CoV-2 vaccination in 13 patients (median age 17 years) receiving chemotherapy for a solid tumor [ 7 ]. Donze et al [ 5 ] evaluated the anti-SARS-CoV-2 immunity in 38 pediatric cancer patients and assessed the humoral, but not the cellular immune response. At 259 days post-vaccination, the probability of maintaining immunity against SARS-CoV-2 declined to 50% in the 15/38 patients who acquired post-vaccination immunity during the first 3 months after vaccination [ 5 ].…”

“…Donze et al [ 5 ] evaluated the anti-SARS-CoV-2 immunity in 38 pediatric cancer patients and assessed the humoral, but not the cellular immune response. At 259 days post-vaccination, the probability of maintaining immunity against SARS-CoV-2 declined to 50% in the 15/38 patients who acquired post-vaccination immunity during the first 3 months after vaccination [ 5 ]. In comparison, our study shows a sustained humoral response at the end of the follow-up period which can be explained by the fact that we did not remove patients with a documented SARS-CoV-2 infection, as this reflects the real-life setting.…”

“…It has become clear that children and adolescents receiving therapy for cancer or undergoing hematopoietic cell transplantation are at an increased risk for severe or even lethal infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [ 1 , 2 ]. Whereas the rapid development of vaccines against SARS-CoV-2 and the successful implementation of vaccine programs resulted in the decrease in morbidity and mortality in risk groups such as elderly individuals or in immunocompromised adults [ 3 , 4 ]; there is limited information on the effectiveness of SARS-CoV-2 vaccination in pediatric patients on active cancer treatment, and data on the long-term follow up are lacking [ 5 – 7 ]. We recently reported on the results of a prospective longitudinal study in 21 pediatric patients receiving chemotherapy for cancer which demonstrated that 3 doses of SARS-CoV-2 mRNA vaccine resulted in both humoral and cellular immunity in most patients [ 6 ].…”