Humoral immune response as an indicator for protection against Covid‐19 after anti‐SARS‐COV2‐booster vaccination in hematological and oncological patients

Abstract

AbstractCancer 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.