The BNT162b2 mRNA COVID-19 vaccine in adolescents and young adults with cancer: A monocentric experience.

BACKGROUND AND

aimsCOVID-19 infection in paediatric patients with cancer is severe or critical in 20% of the patients. It can therefore directly affect paediatric patients with cancer and/or their care. We aimed at evaluating the safety and efficacy of the BNT162b2 mRNA COVID-19 vaccine in adolescents and young adults (AYA) with solid tumour.

methodsThis study includes a retrospective analysis of safety and efficacy of the BNT162b2 mRNA COVID-19 vaccine administered to patients, ≥16 years old, under treatment for a solid tumour or within 6 months after treatment from 15th February 2021 to 15th April 2021. Two administrations of the vaccine 3 weeks apart were given. Sera were tested for anti-SARS-Cov-2 immunoglobulin G (IgG) antibodies directed against the S1 domain of the spike protein. In case of positive serology, neutralisation of SARS-Cov-2 was tested.

resultsTwenty-three patients with solid tumours were identified and proposed to get vaccinated. Nine patients refused, and 1 previously developed COVID-19 infection with positive serology. At the time of writing, 13 patients (10 M/2 F; median age: 17) started vaccination. All patients received 2 injections except 2 patients who stopped vaccination because of tumour progression. Ten patients were under treatment (alone or in combination: chemotherapy: 7 patients [pts], immunotherapy: 2 pts, targeted therapy: 3 pts, follow-up: 3 patients). Overall, vaccines were well tolerated. Five patients did not report any side-effects after the first injection and 4 after the second injection. The main local reactivity symptom was mild pain at the site of injection (6 and 2 pts). Fatigue (2 pts and 5 pts) was the most frequent systemic symptom. One patient refused serology testing. All patients but 1 had pre-vaccination negative serology; 7 of 10 patients tested had positive serology before second vaccine injection, and 9 of 10 patients had positive serology one month after the second injection. All patients with seroconversion had positive COVID-19 neutralisation test. No patient developed COVID infections.

conclusionsWe report the good safety profile and good efficacy of the BNT162B2 vaccine in AYA with solid tumours. Larger series and monitoring of the kinetics of anti-Sars-Cov-2 IgG antibodies for several months are mandatory to confirm these preliminary results and to determine long-term vaccination.