Key clinical point: Suboptimal responses to a single dose of Pfizer-BioNTech BNT162b2 or AstraZeneca ChAdOx1 nCoV-19 vaccines in patients with chronic myeloid neoplasms including chronic myeloid leukemia (CML) highlight a potentially important immunocompromise in this patient population.
Major finding: At 14 days after single vaccination dose, patients with chronic myeloid blood cancers vs health care workers above 60 years of age had significantly lower seroconversion (58% vs 97%) and median anti-S antibody titer (75 vs 630; both P less than .0001). Among disease subgroups, seroconversion was highest in patients with CML (75%) and observed in 83% of patients with CML receiving imatinib.
Study details: Findings are from a real-world analysis of 60 patients with myeloid cancers, including 12 patients with CML and no evidence of prior COVID-19 infection, who received a single dose of either BNT162b2 or ChAdOx1 nCoV-19 vaccines.
Disclosures: This study was funded by the National Institute of Health Research Oxford Biomedical Research Centre. The authors declared no conflicts of interest.
Source: Chowdhury O et al. Br J Haematol. 2021 Jun 16. doi: 10.1111/bjh.17644 .