与普通人群相比，癌症患者在感染 SARS-CoV-2 后出现严重 COVID-19 症状的风险更高，并且经常表现出对 SARS-CoV-2 疫苗接种的免疫反应受损。自 2021 年 10 月起，我们的肿瘤中心在 12 个月内对 357 名患有血液和肿瘤疾病的患者进行了中和抗体监测。所有患者均接受了 3 次 mRNA 疫苗（Comirnaty/BionTech 或 Spikevax/Moderna）或载体疫苗（Vakzevria/AstraZeneca 或 JCOVDEN/Johnson）疫苗接种

Cancer patients are at a higher risk to develop severe COVID-19 symptoms after SARS-CoV-2 infection compared to the general population and regularly show an impaired immune response to SARS-CoV-2 vaccination. In our oncological center, 357 patients with hematological and oncological diseases were monitored for neutralizing antibodies from October 2021 over 12 months. All patients had received three anti-SARS-CoV-2 vaccinations with an mRNA-(Comirnaty/BionTech or Spikevax/Moderna) or a vector vaccine (Vakzevria/AstraZeneca or JCOVDEN/Johnson&Johnson). Neutralizing anti-SARS-CoV-2 IgG antibodies in the patients' sera were detected within 3 months before, 3-10 weeks and 5-7 months after the booster vaccination (third vaccination). 112 patients developed a breakthrough SARS-CoV-2 infection during the observation period. High anti-SARS-Cov-2 antibody levels before infection significantly protected against symptomatic Covid-19 disease (p = .003). The median antibody titer in patients with asymptomatic Covid-19 disease was 2080 BAU/ml (binding antibody units per Milliliter) and 765 BAU/ml in symptomatic patients. 98% of the solid tumor patients reached seroconversion after the booster vaccination in comparison to 79% of the hematological patients. High antibody titers of >2080 BAU/ml after the booster vaccination were detected in 61% of the oncological and 34.8% of the hematological patients. 7-10 months after the booster vaccination, the anti-SARS-CoV-2 antibody titer declined to an average of 849 BAU/ml. Considering the heterogenous humoral immune response of cancer patients observed in this study, an individual vaccination strategy based on regular measurement of anti-SARS-CoV-2 antibody levels should be considered in contrast to fixed vaccination intervals.© 2024 The Author(s). International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.