BNT162b2 mRNA Covid-19 Vaccine in AYA with cancer: a monocentric experience

Revon-Riviere, Gabriel; Ninove, Laetitia; Min, Victoria; Rome, Angélique; Coze, Carole; Verschuur, Arnauld; de Lamballerie, Xavier; André, Nicolas

BACKGROUND AND AIMS: COVID-19 infection in pediatric cancer patients is severe or critical in 20% of the patients. It can therefore directly affect pediatric cancer patients and/or their care. We aimed at evaluating the safety and efficacy of BNT162b2 mRNA Covid-19 vaccine in AYA with solid tumor. METHODS: Retrospective analysis of safety and efficacy of BNT162b2 mRNA Covid-19 vaccine administered to patients, >= 16 years old, under treatment for a solid tumor or within 6 months’ post-treatment from 15/2/2021 to 15/4/2021. Two administrations of the vaccine 3 weeks apart were given. Sera were tested for anti-SARS-Cov-2 IgG antibodies directed against the S1 domain of the spike protein. In case of positive serology, neutralization of SARS-Cov-2 was tested. RESULTS: Twenty-three patients with solid tumors were identified and proposed to get vaccinated. Nine patients refused and 1 previously developed COVID-19 infection with positive serology. At time of writing, 13 patients (10 M/2F); median age: 17) started vaccination. All patient received 2 injections except 2 patients who stopped vaccination because of tumor progression. Ten patients were under treatment (chemotherapy-7pts, immunotherapy-2 pts, targeted therapy-2 pts-follow-up 3 patients). Overall, vaccines were well tolerated. Five patients did not report any side-effect after the first injection and 4 after the second injection. Main local reactivity symptom was mild pain at the site of injection (6 and 2 pts). Fatigue (2pts and 5 pts) was the most frequent systemic symptom. One patient refused serology testing. All patients but 1 had pre-vaccination negative serology, 7/10 tested had positive serology before second vaccine injection, 9/10 had positive serology one month after the second injection. All patients with seroconversion had positive COVID-19 neutralization test. No patient developed COVID infections. CONCLUSIONS: We report the good safety profile and good efficacy BNT162B2 vaccine in AYA with solid tumors. 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.