The immune response to Covid-19 mRNA vaccination among Lymphoma patients receiving anti-CD20 treatment

The monoclonal antibody rituximab improves clinical outcome in the treatment of CD20-positive lymphomatous neoplasms, and it is an established drug for treatment of these cancers. Successful mRNA COVID-19 (SARS-CoV-2) vaccination is extremely important for lymphoma patients because they tend to be elderly with comorbidities which leaves them at increased risk of poor outcomes once infected by Coronavirus. Anti-CD20 therapies such as rituximab, deplete B-cell populations and can affect vaccine efficacy. Therefore, a knowledge of the effect of COVID-19 vaccination in this group is critical. We followed a cohort of 28 patients with CD20-positive lymphomatous malignancies treated with rituximab that started prior to their course of COVID-19 vaccination, including boosters. We assayed for vaccine “take” in the humoral (IgG and IgA) and cellular compartment. Here, we show that short-term and long-term development of IgG and IgA antibodies directed toward COVID-19 spike protein are reduced in these patients compared to healthy controls. Conversely, the robustness and breath of underlying T-cell response is equal to healthy controls. This response is not limited to specific parts of the spike protein but spans the spike region, including response to the conserved Receptor Binding Domain (RBD). Our data informs on rational vaccine design and bodes well for future vaccination strategies that require strong induction of T-cell responses in these patients.


CD4 T cell Response
. Comparison of peak CD4 T cell response.
Table S3.Comparison of Peak T cell response.Peak T cell responses are log2 transformed to reduce skewness.A two-sample t-test was used to compare peak T cell response between patients and controls, Females and Males, or Vaccine (Pfizer vs. Moderna) when PBMC are restimulated with overlapping peptides, and control vs. patient when PBMC are re-stimulated with whole spike protein, or with the Receptor Binding Domain protein.

Table S4. A comparison of antibody induction and analysis of correlation between IgA and IgG.
Table S4.Both lgG and lgA were log2 transformed to reduce skewness.Two mixed effects models were fitted to compare vaccine differences in IgG and lgA respectively, and two mixed effects models were fitted to compare gender differences in IgG and lgA respectively.In all 4 models, the random effect was the individual person.The results of the 4 models are summarized.No vaccine or gender difference comparing IgG or lgA induction was statistically significant.Graph: All lgA and lgG measures from blood samples drawn before the booster vaccination.For patients who received only one vaccine, all their blood samples were used.The Spearman correlation between lgA and lgG is R1=0.7457.These data are plotted in black "x" below.
Individuals receiving sample: all lgA and lgG measures from blood samples drawn after the first vaccine.Only patients who received the second vaccine were included.The Spearman correlation between lgA and lgG is R=0.5043.These data are plotted in red "+" below.
The reason for using a Spearman correlation is because both lgA and lgG data are highly skewed.

Table S5. Comparison of patient with control response to individual peptide pools that cover the vaccine immunogen spike protein.
Table S5.A comparison of patient with control response to individual peptide pools that cover the vaccine immunogen spike protein.A log2(x+1) transformation was applied to the breath (total of the 9 pools) to reduce skewness.We fitted data using a mixed effects model with group (patient or control) as a fixed effect and patient ID as random effect.The estimated fixed effect of the group is beta=-1.9551.488 (p=0.1930).Data are dichotomized by 40 or <40.We use two methods to compare each of these nine pools between cases (patients) and controls: Scatter plot comparing peak T cell INFg response to re-stimulation with Spike peptides and the number of days between the last Rituximab dose and first Covid-19 vaccination.Right; Scatter plot comparing peak T cell INFg response to re-stimulation with Spike peptides and patient age.
(1) Fisher's exact test; (2) logistic regression that adjusts for gender.Prop Control=proportion of controls with pool values 40 or above; Prop Patient=proportion of patients with pool values 40 or above.P value Fisher= p value from Fisher's exact test.Beta regression=coefficient from logistic regression for cases (vs controls).St.dev regression=standard error of Beta regression.P value regression = p value from the logistic regression.

Table S2 . Comparison of peak CD4 T cell response vs Timing of rituximab administration and Covid-19 vaccination.
Scatter plot comparing peak T cell INFg response to re-stimulation with Spike peptides and the number of days between the last Rituximab dose and first Covid-19 vaccination.Right; Scatter plot comparing peak T cell INFg response to re-stimulation with Spike peptides and patient age. Left;