Dados do Resumo

Título

Protective humoral and cellular response post-covid-19 vaccination in immunocompromised patient under active oncological treatment

Introdução

Patients with cancer have a higher risk of severe coronavirus disease 2019 (covid-19) and associated mortality than the general population. Owing to this increased risk, patients with cancer have been considered a priority for covid-19 vaccination worldwide, for both primary and booster vaccinations. However, since these patients have not been included in pivotal clinical trials, considerable uncertainty remains regarding the efficacy of the vaccine, the extent of humoral and cellular immune responses in these patients, and the risks of vaccine-related adverse events.

Objetivo

Therefore, this study aimed to evaluate the efficacy and reactogenicity of this immunosuppressed subgroup of patients.

Métodos

The study was approved by the Research Ethics Committee of the Oswaldo Cruz Foundation and by the National Research Ethics Commission (approval number 30428720.3.0000.5091). A total of 173 patients with cancer were included in the study, and 140 healthy volunteers were included in the control group. To assess the humoral response and measure the level of immune protection, an ELISA IgG anti-spike technique was performed. In addition, cellular responses were analyzed using a high-throughput human cytokine system. Finally, these findings were associated with tumor- and vaccine-determined variables.

Resultados

It was noted that patients who had been infected before starting vaccination had more adverse effects than those who had been infected after starting the vaccination protocol. In addition, the adverse effects of vaccination were mild in both. The patients received different vaccination protocols consisting of homologous and heterologous doses and obtained a seropositivity rate of 90.9% with mild adverse effects (healthy volunteer rate was 93,9%). The data showed that cancer patients have long-lasting immunological protection for up to 18 months as the analyzed time. Age, distant metastasis, combined treatment, and radiotherapy have affected the seropositivity rate in cancer patients. Soluble markers were reduced compared to healthy individuals and showed little variation compared to healthy participants. This variation was observed at the first observation time, which was justified by the inflammatory process characteristic of systemic antineoplastic treatments. No changes characteristic of severe inflammatory or pro-inflammatory conditions were observed due to the vaccines, confirming their safety.

Conclusões

This study highlighted the efficacy of covid-19 vaccines available in Brazil and administered to patients with cancer as well as the low occurrence of adverse effects following immunization. Despite having a lower seropositivity rate, protection was sustained for at least 18 months after administration of the SARS-CoV-2 response booster. Further studies with larger sample sizes are needed to determine the type of effective vaccine and vaccine dose for cancer patients so that they can be protected from covid-19-related morbidity and mortality without interrupting their cancer treatment.

Financiador do resumo

Fundação Oswaldo Cruz, CAPES, Fapemig (004/2022)

Palavras Chave

covid-19 safety; covid19 and cancer patients; vaccine