key: cord-0923189-hd0axs5o
authors: Tvito, Ariella; Ronson, Aaron; Ghosheh, Renan; Kharit, Mira; Ashkenazi, Jakob; Magen, Sophie; Broide, Ellen; Benayoun, Emmanuel; Rowe, Jacob M; Ofran, Yishai; Ganzel, Chezi
title: Anti-CD20 monoclonal antibodies inhibit seropositive response to Covid-19 vaccination in Non-Hodgkin lymphoma patients within six months after treatment
date: 2021-12-22
journal: Exp Hematol
DOI: 10.1016/j.exphem.2021.12.396
sha: 331b752e60112668d78a492f305abddf048b2b9b
doc_id: 923189
cord_uid: hd0axs5o

The Covid-19 pandemic caused millions of death worldwide. Vaccines have been developed but patients on immunosuppressive therapy are less likely to respond. This study aimed to investigate the efficacy of Covid-19 vaccine (Pfizer-BioNTech) in patients with non-Hodgkin lymphoma, treated with anti-CD20 monoclonal antibodies. Only one of 28 lymphoma patients (3.6%) developed a seropositive response compared to 100% (28 of 28) of the healthy volunteers. The low levels of CD19+ lymphocytes among the lymphoma patients suggest that the anti-CD20 treatment prevents the seropositive response to the vaccine. An additional vaccination might be indicated in these patients, once B cells are repopulated.

The novel Coronavirus Covid-19 has afflicted millions of people worldwide. Several vaccines have been developed to contain the pandemic. The BNT162b2 vaccine tested in 43,548 participants, showed a 95% protection against Covid-19 [1] . Comparable results were achieved in a phase III trial testing the mRNA-1273 [2] . Based on these results, BNT162b2 and mRNA 1273 received global approval and individuals are being vaccinated worldwide.

Patients with an immuno-compromising condition or on immunosuppressive therapy were excluded in the above trials and there are no data regarding the efficacy of the vaccine in this population. A concerning subgroup are patients treated with anti-CD20 monoclonal antibodies (mAbs). These agents have been incorporated as standard of care in the treatment of CD20-positive B cell lymphomas. Anti-CD20 mAbs deplete normal B cells and thus impair humoral response.

In a study of lymphoma patients who received a rituximab-containing treatment regimen within the previous six months, none of 67 patients developed seroprotective titers following administration of an adjuvanted inactivated pandemic H1N1 influenza A vaccine. In contrast, 42 of 51 healthy controls (82 percent) developed seroprotective titers following vaccination [3] .

Nonetheless the guidelines of the Israel health ministry, based on expert opinion, recommend to vaccinate patients who receive immunosuppressive therapy [4] .

The aim of this study was to determine the efficacy of the Covid-19 vaccine in hematological patients treated with anti-CD20 mAbs during six months prior to the vaccination. Of additional interest was to assess a correlation between B cell depletion and the efficacy of the vaccine.

Patients eligible for the study were adults with an established diagnosis of non-Hodgkin lymphoma (NHL) receiving anti-CD20 mAbs as a single agent or in combination with chemotherapy. Patients not on active treatment were eligible if treatment of anti-CD20 mAbs had been completed within the last 6 months prior to the first vaccination. Controls were volunteers without hematological disease. Patients with chronic lymphocytic leukemia/small lymphocytic lymphoma and patients or volunteers with previous laboratory confirmed Covid-19 infection were excluded.

All participants received two Covid-19 vaccines (Pfizer-BioNTech), 21 days apart. Between day 7 and 72 after their second vaccination blood samples were drawn for Covid-19 serology. The antibody response to vaccine was measured using the Abbott Architect Sars-Cov-2 IGG II immunoassay targeting Spike IgG. Level of 150 AU/ml was considered positive. Patients with positive Spike IgG were subsequently tested with Abbott Architect SARS-CoV-2 IgG assay targeting nucleocapsid to rule out past infection by Covid-19. Additional laboratory parameters evaluated included complete blood count, immunoglobulin levels and peripheral blood lymphocyte subset analysis measured by flow cytometry. Markers for B cells were CD 19 and CD40, for memory B cells CD27 and for T cells CD3, CD4 and CD8. The study was approved by the Ethics Committee of Shaare Zedek medical center. All participants gave written informed consent.

28 NHL patients and 28 controls were recruited for this study. Patient characteristics and clinical data are listed in Table 1 . The controls included 22 female and 6 male volunteers with a median age of 50 years (range 27-75). Most patients received combined treatment of chemotherapy and anti-CD20 antibody, 3 patients received rituximab as a single agent and 12 got rituximab as maintenance therapy.

Among 28 lymphoma patients, only one patient developed seropositive response after Covid-19 vaccination. In contrast, all the controls had a high Sars-Cov-2 IGG levels ( Figure 1 ). This gives a seropositive rate of 3.6% in patients versus 100% in controls. Low levels in at least 1 class of immunoglobulins were observed in 16 patients (57%). CD3⁺, CD4⁺ and CD 8⁺ cell counts were within normal range in all patients. No CD19-positive lymphocytes were detected in 27 of 28 patients.

In the current study, almost all lymphoma patients treated with anti-CD20 mAbs alone or in combination with chemotherapy failed to show a seropositive response after Covid-19 vaccination. CD19 count was low in 27 of 28 lymphoma patients. During a follow up period of 3 months only one of these patients developed mild Covid-19 infection.

One NHL patient had a seropositive result after Covid-19 vaccination. This was an 80 year old patient who had been diagnosed with Helicobacter Pylori-negative gastric marginal zone lymphoma, stage I. He received 4 courses of single agent rituximab, once weekly and 4 additional courses once monthly, the last one two months before he got vaccinated for Covid-19. His immunoassay for spike protein was positive. No antibodies against Sars-Cov-2 nucleocapsid protein were detected, implying no prior Covid-19 infection. His CD19 lymphocyte count was 0. Lymphocyte count and immunoglobulins were within normal range. There was no apparent explanation why this patient, in contrast to all the other NHL patients, developed a seropositive response. 8 months after his last rituximab treatment, the patient received his third vaccination for Covid-19. A month later he had sustained seropositive response. CD-19 positive lymphocytes were detected.

In a study assessing humoral response to influenza vaccination in patients with NHL, patients not needing treatment showed a good serological response to H1N1 vaccinations [5] . In the same study, patients treated with chemotherapy without rituximab also had a sufficient immune response although not as good as healthy controls. In contrast, Yri et al. describes 67 lymphoma patients treated with rituximab, none having a seropositive result after H1N1 vaccination including patients treated with rituximab only. It was suggested that the reason for non-responsiveness in his patient group is B-cell depletion caused by rituximab [3] . Additional studies with smaller patient numbers showed similar results. None of the patients who received rituximab in studies by Ljungman [6] or Takata [7] developed immunity to the influenza vaccine administered.

In a recent meta-analysis evaluating vaccine responsiveness following anti-CD20 therapy, patients on active (<3 months since last dose) anti CD20 therapy had poor responses to all types of vaccines and abrogated response for at least 6 months following treatment. For all vaccine types, response improved incrementally over time, but did not reach the level of healthy controls even 12 months after therapy [8] .

The present study tests humoral response to Covid-19 vaccination in NHL patients treated with anti-CD20 mAbs. The results strongly suggest that most patients with low CD19 lymphocyte count due to treatment with anti-CD20 mAbs do not achieve a seropositive response after Covid-19 vaccination.

Tzarfati et al. showed a lower serologic response in patients with hematologic malignancies following BNT162b2 vaccination (75% versus 99%, p<0.001). Patients treated with anti Cd20 antibodies had significantly less seropositive resposes and lower median antibody titers [9] .

Bonelli et al. report similar results in a study evaluating the humoral and cell mediated response in 5 patients with rheumatologic disease [10] . They had received their last treatment of rituximab 4-12 month prior to Covid-19 vaccination. Three of these patients did not have detectable CD19+ B cells and did not develop antibody response whereas two of the patients with detectable CD19+ B cell showed antibody response. Despite diminished humoral response, interferon-γ response to Sars-Cov-2 peptides was observed in all patients suggesting T-cell activity irrespective of the antibody response. However there are no data yet whether T-cell activity is sufficient to protect vaccinated patients from Covid-19 infection.

In an additional study, Bedognetti et al. evaluated the humoral response to influenza vaccine in 14 NHL beyond the rituximab treatment period compared with healthy volunteers. Median time after rituximab was 33 months (range = 14-78), B-cell proportions (CD19+) were in patients and volunteers were similar. Even though patients had an attenuated response to influenza antigens, they did reach acceptable seroprotection rates [11] .

We recognize that the ideal control cohort would consist of patients with NHL who were never treated with those who did not receive rituximab. However due to the universal acceptance of monoclonal anti-CD20 therapy as standard of care in NHL, such a population is exceedingly uncommon.

In conclusion, patients and physicians should be aware that vaccination within 6 months of treatment with anti-CD20 mAbs and may not confer immunity against Covid-19. Vaccination of close contacts, adherence to hygiene, social distancing and particularly avoidance of close contact with ill people might be needed to optimally protect this population from Covid-19. For patients expected to need anti-CD20 monoclonal antibodies in the near future, vaccination against Covid-19 before treatment should be considered. Although intuitive, additional studies are necessary to confirm whether a third vaccination is indicated in patients after treatment with anti-CD20 mAbs, once peripheral B cells are repopulated. 

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine

Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine

Rituximab blocks protective serologic response to influenza A (H1N1) 2009 vaccination in lymphoma patients during or within 6 months after treatment

Ministry of Health, Israel, Epidemiology department. Vaccine instruction

Immunogenicity of Influenza Vaccination in Patients with Non-Hodgkin Lymphoma

Vaccination of patients with haematological malignancies with one or two doses of influenza vaccine: a randomized study

Attenuated antibody reaction for the primary antigen but not for the recall antigen of influenza vaccination in patients with non-Hodgkin B-cell lymphoma after the administration of rituximab-CHOP

Vaccine response following anti-CD20 therapy: a systematic review meta-analysis of 905 patients

BNT162b2 COVID-19 Vaccine is significantly less effective in patients with hematologic malignancies

SARS-CoV-2 vaccination in rituximab-treated patients: evidence for impaired humoral but inducible cellular immune response

Seasonal and pandemic (A/H1N1 2009) MF59-adjuvanted influenza vaccines in complete remission non-Hodgkin lymphoma patients previously treated with rituximab containing regimens

Figure 1: Sars-Cov-2 IGG levels after Covid-19 vaccination in patiens after treatment with monoclonal anti-CD20 antibodies and in controls

* 4 patients after R-CHOP, 1 after R-CVP

CHOP= cyclophosphamide, doxorubicin, vincristine and prednisone. mAbs= monoclonal antibodies

Immunoglobulins IGG (mg/dl), median (range)

IGA (mg/dl), median (range)

IGM (mg/dl), median (range)

Immuno-phenotyping CD3 count (% of lymphocytes), median (range)

CD4 count (% of CD3+ cells), median (range)

CD8 count (% of CD3+ cells), median (range)

CD19 count (% of lymphocytes), median (range) 0

Contribution: A.T and C.G. designed the study, provided data, analyzed data and wrote the paper; A.R., R.G., M.H., J.A. and JM. R. provided data. S.M. E.B. and E.B performed laboratory analyses.Conflict-of interest disclosure: The authors declare no competing financial interests