Safety and tolerability of COVID-19 vaccines in patients with cancer: a single center retrospective analysis

Abstract Background: Severe acute respiratory syndrome coronavirus 2 disease (COVID-19) has caused a worldwide challenging and threatening pandemic. Multinational, placebo-controlled, observer-blinded trials were conducted since the beginning of pandemic because safe and effective vaccines were needed urgently. In most trials of COVID-19 vaccines patients (pts) affected by malignancies or on treatment with immunosuppressive drugs were excluded. Patients and methods: At our Centre a retrospective study was conducted in this subset of population to investigate safety and tolerability of COVID-19 vaccines; 377 pts with solid tumor on treatment were enrolled. Vaccine-related adverse events were recorded using a face-to-face questionnaire including a toxicity grading scale. Most of the pts (93.5%) has got mRNA vaccine as indicated by Italian health ministry guidelines. Mean age was 66 years (range 27-87), 62.3% of the pts was older than 65 years and 68.4% had at least one additional comorbidity. The majority (86.2%) of pts was at metastatic stage and 29.4% received immunotherapy-based treatment. For statistical analysis multivariate binary logistic regression models were performed and linear regression models were applied, using SPSS technology v.27.Results: Incidence of adverse events was higher after the second dose than after the first one (72.6% vs 67.4%). Adverse events were mild and transient, ended in a few days without any sequelae. No severe or uncommon side effects were recorded. In multivariate analysis we found that female gender was associated with a greater risk of more severe and longer lasting adverse events, and a higher risk of adverse events was found for pts treated with immunotherapy. Conclusions: Our results demonstrate that COVID-19 vaccines were safe and well-tolerated in our population.