Radiation recall dermatitis induced by COVID-19 vaccination in breast cancer patients treated with postoperative radiation therapy.

BACKGROUND: and purpose: Radiation recall dermatitis is an adverse event predominantly due to systemic therapy administration after a previous radiation therapy course. Few case reports describe radiation recall dermatitis in breast cancer patients treated with postoperative radiation therapy following COVID-19 vaccination. In this study we investigated the incidence and severity of radiation recall dermatitis after COVID-19 vaccination in irradiated breast cancer patients. METHODS: Patients that received at least one COVID-19 vaccination dose during the year after the end of postoperative breast radiation therapy were included in this observational monocentric study. Local symptoms occurring inside the radiation field after vaccination were patient-reported and scored according to the PRO-CTCAE questionnaire. Descriptive data of radiation recall dermatitis incidence and severity, and potential risk factors were evaluated. RESULTS: A cohort of 361 patients with 756 administered COVID-19 vaccinations was analyzed. Breast symptoms were reported by 7.5% of patients, while radiation recall dermatitis was considered for 5.5%. The incidence of radiation recall dermatitis per single dose of vaccine was 2.6%, with a higher risk for the first dose compared to the second/third (4.4% vs 1%, p = 0.003), especially when administered within the first month after the end of irradiation (12.5% vs 2.2%, p = 0.0004). Local symptoms were generally self-limited and a few cases required anti-inflammatory drugs. CONCLUSIONS: Radiation recall dermatitis is an uncommon but not rare phenomenon in breast cancer patients that received COVID-19 vaccination within one year after breast irradiation. However, symptoms severity were generally low/mild and reversible. These findings can be useful for patient counseling.

IgG antibodies against SARS-CoV-2 decay but persist 4 months after vaccination in a cohort of healthcare workers.

BACKGROUND AND AIMS: Monitoring the immune response against SARS-CoV-2 is pivotal in the evaluation of long-term vaccine efficacy. Immunoglobulin G (IgG) antibodies represent an advisable tool to reach this goal, especially for the still poorly defined antibody trend induced by the new class of mRNA vaccines against SARS-CoV-2. MATERIALS AND METHODS: Anti-Spike RBD IgG antibodies were monitored in a cohort of healthcare workers at CRO Aviano, National Cancer Institute, through MAGLUMI® chemiluminescence assay, at 1 and 4 months after full-schedule of BNT162b2 or mRNA-1273 vaccination. RESULTS: At 1 month after vaccination, 99.9% of 767 healthcare workers showed a reactive antibody response, which was inversely correlated with age, and positively associated with a previous history of COVID-19, and mRNA-1273 vaccination. Serological response was maintained in 99.6% of the 516 subjects monitored also at follow-up. An antibody decay from 559.8 AU/mL (IQR 359.7-845.7) to 92.7 AU/mL (IQR 65.1-148.6; p < 0.001) was observed, independently from age and sex. CONCLUSION: Our data supported the ability of SARS-CoV-2 mRNA vaccines to induce at least a 4 months-lasting IgG response, even outside the rules of clinical trials. The antibody decay observed at follow-up suggested to deepen the immune response characterization to identify subjects with low anti-SARS-CoV-2 immunity possibly requiring a vaccination boost.