The urgency of the COVID-19 pandemic has led to accelerated vaccine development within less than a year. Immunocompromised patients with hematological malignancies are more susceptible to COVID-19 and at higher risk of severe complications and worse outcomes compared with general population. In this context, we evaluated the humoral response by determining the titers of neutralizing antibodies (NAbs) against SARS-CoV-2 in patients with Waldenstrom Macroglobulinemia (WM) after vaccination with the BNT162b2 or AZD1222 vaccine. An FDA-approved, ELISA-based methodology was implemented to evaluate NAbs on the day of the first vaccine shot, as well as on day 22 and 50 afterwards. 106 patients with WM (43% males, median age 73 years) and 212 healthy controls (46% males, median age 66 years) who were vaccinated during the same period, at the same center were enrolled in the study (which is registered at www.clinicaltrials.gov as NCT04743388). Our data indicate that vaccination with either 2 doses of the BNT162b2 or 1 dose of the AZD1222 vaccine leads to lower production of NAbs against SARS-CoV-2 in patients with WM compared with controls both on day 22 and on day 50 (P<0.001 for all comparisons). Disease-related immune dysregulation and therapy-related immunosuppression are involved in the low humoral response. Importantly, active treatment with either Rituximab or Bruton's Tyrosine Kinase inhibitors was proven as an independent prognostic factor for suboptimal antibody response following vaccination. In conclusion, patients with WM have low humoral response following COVID-19 vaccination, which underlines the need for timely vaccination ideally during a treatment-free period and for continuous vigilance on infection control measures.
Poor neutralizing antibody responses in 106 patients with WM after vaccination against SARS-CoV-2: a prospective study