A study published in The Lancet Haematology reviewed responses to the first dose of the SARS-CoV-2 vaccine in patients with multiple myeloma (MM).
The investigators retrospectively reviewed serological responses in 93 patients with MM in the United Kingdom who had received the first of two vaccine doses, either Pfizer or AstraZeneca. The cohort had a median of one previous lines of therapy (range, 0-8) and 66 patients (71%) were actively on therapy at vaccination. Patients underwent SARS-CoV-2 IgG antibody analysis at a median of 33 days post vaccination.
Overall, 52 patients (56%) tested positive for SARS-CoV-2 IgG antibodies at first analysis. There was no difference in antibody positivity rate between vaccine types. There were also no differences in positivity rates based on age, sex, disease type, or time from vaccination to antibody test.
There were differences in seropositivity rates between patients who had a very good partial response (75%) or a complete response (63%) to treatment when compared with patients who had stable or progressive disease (30%). Being on active therapy at time of vaccination was associated with an overall lower seropositivity rate compared to patients not receiving treatment. Of eight patients who underwent autologous hematopoietic cell transplantation (AHCT) within one year of vaccination, six patients (75%) were positive for antibodies, all of whom were in at least a partial response to treatment.
The investigators also conducted a Total antibody assay, which measures IgG, IgM, and IgA levels, on 40 patients that were IgG negative upon first assessment. Thirteen (33%) of these patients were seropositive on the Total antibody assay, bringing the total number of patients with antibody development to 65 (70%) of 93.
“Our data suggest that most patients with MM are likely to have some protection after one vaccination, which might improve after second vaccination. We saw no serious COVID-19 infections or associated deaths in this cohort during the period of data collection, but longer follow-up is needed to assess the degree of clinical protection from severe COVID-19 infection afforded by vaccination,” wrote the authors in conclusion. “That at least 30% of patients did not have a positive antibody test after first vaccination is concerning, and it will be important to track this group closely, as non-responders could be left vulnerable to severe COVID-19 infection.”