Neutralizing Antibody Response After COVID-19 Vaccination: Great Variation Among Patients With Myeloma

By: Celeste L. Dixon
Posted: Friday, May 20, 2022

Vaccines against SARS–CoV-2 may be less effective in patients with multiple myeloma than previously thought, and substantially less effective than in the general population, based on a result reported in the Journal of Clinical Oncology. Vaccine-induced neutralizing antibodies, now recognized as critical for protective immunity, were present in just 54% of more than 200 patients who had received a current RNA vaccine (Moderna or Pfizer), according to Ajay K. Nooka, MD, of Emory University, Atlanta, and colleagues. Other findings were that induction of neutralizing antibodies appears to be affected by race (higher in Black patients), vaccine (higher with Moderna), and myeloma therapy (lower with anti-CD38 antibodies).

The team analyzed sera from patients with multiple myeloma who had received Pfizer (n = 144) and Moderna (n = 84) vaccines, testing the capacity of the antibodies created to neutralize both the initial SARS–CoV-2 strain and the Delta variant. The 54% rate of detectable neutralizing antibodies was “much lower than estimated in previous seroconversion studies in multiple myeloma, which did not monitor viral neutralization,” wrote the investigators. The difference between vaccines was significant, however: patients who received the Moderna versus Pfizer vaccine had greater induction of neutralizing antibodies (67% vs. 48%; P = .006). The reason is unknown but could relate partly to a higher antigen dose in the Moderna vaccine or differences in the vaccine schedule, noted the authors.

Furthermore, anti-CD38 antibodies had a “profound impact” on the induction of neutralizing antibodies (36.5% vs. 61.6% for patients receiving vs. not receiving this therapy; P < .0001). These patients, then, seem to be at the highest risk of contracting COVID-19 despite vaccination, posited Dr. Nooka and colleagues. The findings “also emphasize the urgent need to pursue additional strategies to protect these patients, with higher-dose booster vaccines, or prophylactic administration of monoclonal antibodies, and surveillance for emergence of variants” in this population. Overall, the data also indicate that previous exposure to or illness from a COVID-19 variant should not prevent any patient with multiple myeloma from being vaccinated, they added.

Disclosure: The study authors’ disclosure information can be found at ascopubs.org.

Journal of Clinical Oncology

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