Willingness to receive COVID-19 vaccination and adverse effects after vaccination in breast cancer survivors during the COVID-19 pandemic: a cross-sectional retrospective study of a Chinese population.

Background: Breast cancer (BC) patients have a higher mortality rate after COVID-19 infection, but data on vaccination of BC patients and attitude towards COVID-19 vaccination and safety after vaccination are lacking. We wanted to understand the willingness and factors of BC survivors to receive a COVID-19 vaccine, and their adverse reactions. The purpose is to judge the safety of vaccination, and find strategies to promote vaccination in BC patients. Methods: Offline and online questionnaire surveys were provided in outpatient clinics and on an online follow-up platform, respectively, to collect information. Factors influencing vaccination willingness were analyzed by univariate and multivariate logistic regression. All statistical tests were performed bilaterally, and a P value <0.05 was considered statistically significant. Patients who have been vaccinated need to fill in questions about the impact on quality of life after vaccination, the type and frequency of vaccination, and side effects. Results: A total of 497 valid questionnaires were collected; 289 (58.1%) BC survivors were vaccinated with a COVID-19 vaccine, and 379 (76.26%) BC survivors had a fully or basically accepting attitude toward vaccination. Survivors over 70 years of age, educated only to high school level, and those receiving chemotherapy had significantly lower levels of acceptance of COVID-19 vaccines. Multivariate logistic regression analyses suggested that treatment status and cognitive attitude were independent factors influencing COVID-19 vaccination among BC survivors. The main reason for being vaccinated was "doctor recommendation" (57.26%). Unwillingness to receive a COVID-19 vaccine was mainly due to "the unknown safety of the vaccine in cancer patients" (67.80%). A total of 97.56% of the survivors believed that vaccination had no or almost no effect on their quality of life. Among the BC survivors, 18 (6.23%) had adverse reactions after vaccination. All adverse reactions were grade 1 or 2, and no adverse reactions of grade 3 or above were reported. The adverse reactions reported by 15 survivors (83.33%) markedly improved within 1 week. Conclusions: In terms of cognitive attitudes toward COVID-19 vaccines, elderly individuals and those with a lower education level were less receptive to vaccination. Therefore, attention to elderly survivors can help improve the vaccination rate.