The following article features coverage from the 2021 American Society of Hematology Annual Meeting. Click here to read more of Cancer Therapy Advisor’s conference coverage.

About 15% of patients with hematologic disorders enrolled in a prospective study had a negative antibody response at least 2 weeks after receiving their second COVID-19 vaccination.

Among patients who failed to seroconvert, 72% had lymphoid neoplasms, and patients with indolent or aggressive non-Hodgkin lymphoma (NHL) had the highest rates of negative antibody response. However, seroconversion was observed in 99% of patients with chronic myeloid leukemia (CML).

These results were presented at the 2021 American Society of Hematology (ASH) Annual Meeting by Jil Rotterdam, a medical student at Universität Heidelberg in Mannheim, Germany.

Continue Reading

Study Details

This single-center study included 373 patients with hematologic disorders. The median patient age was 64 years (range, 20-92 years), and 44% were women.

Most patients (n=338) had a hematologic malignancy, including myeloid (n=227) and lymphoid (n=111) neoplasms. Thirty-five patients had a nonmalignant hematologic disease, including autoimmune diseases (n=26) and benign disorders (n=9).

There were 229 patients (61%) receiving active therapy, and 144 patients (39%) who had been treated previously or were treatment naïve.

Patients received 2 doses of the Pfizer-BioNTech vaccine (n=289), Moderna vaccine (n=36), or AstraZeneca vaccine (n=26), or a first dose of the AstraZeneca vaccine with a second dose of the Pfizer-BioNTech vaccine (n=22).

The researchers used an electrochemiluminescence assay (Elecsys, Roche) to quantify antibody levels (pan-immunoglobulin) against the receptor-binding domain of the SARS-CoV-2 spike protein at least 2 weeks after the second COVID-19 vaccination.


The median time from vaccination to analysis was 12 weeks. The vaccination-related antibody response was positive (≥0.8 U/mL) in 85% of patients (317/373), with a mean value of 197 U/mL.

The vaccination-related antibody response was negative (<0.8 U/mL) in 15% of patients (56/373). Among patients with a negative response, 72% (n=40) had lymphoid neoplasms, 21% (n=12) had myeloid neoplasms, and 7% (n=4) had an autoimmune disease.

Most patients with a negative response were receiving active therapy (71%, n=39). Therapies associated with negative results included Bruton tyrosine kinase inhibitors, immunoglobulins, and rituximab. Tyrosine kinase inhibitors were associated with positive results.

The proportion of patients with a negative antibody response, by disease type, was:

  • 42% in indolent NHL (25/60)
  • 44% in aggressive NHL (8/18)
  • 24% in myelodysplastic syndromes (5/21)
  • 13% in multiple myeloma (4/31)
  • 11% in Hodgkin lymphoma (1/9)
  • 5% in acute leukemia (1/20)
  • 8% in myeloproliferative neoplasms (6/76)
  • 1% in CML (1/101).

“Some patients with hematological diseases do not have adequate antibody response and might therefore not have sufficient protection from vaccination,” Ms Rotterdam said. “[W]e should recommend ongoing protective measures, such as masks, social distancing, and screenings, as well as prioritizing vaccination for family members and caregivers to protect the patients.”

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Read more of Cancer Therapy Advisor’s coverage of the ASH 2021 meeting by visiting the conference page.


Rotterdam J, Thiaucourt M, Schwaab J, et al. Antibody response to vaccination with BNT162b2, mRNA-1273, and ChADOx1 in patients with myeloid and lymphoid neoplasms. Presented at ASH 2021; December 11-14, 2021. Abstract 218.