Humoral serologic response to the BNT162b2 vaccine is abrogated in lymphoma patients within the first 12 months following treatment with anti-CD2O antibodies

Management of vaccinations in patients with non-Hodgkin lymphoma

Vaccinations are fundamental tools in preventing infectious diseases, especially in immunocompromised patients like those affected by non-Hodgkin lymphomas (NHLs). The COVID-19 pandemic made clinicians increasingly aware of the importance of vaccinations in preventing potential life-threatening SARS-CoV-2-related complications in NHL patients. However, several studies have confirmed a significant reduction in vaccine-induced immune responses after anti-CD20 monoclonal antibody treatment, thus underscoring the need for refined immunization strategies in NHL patients. In this review, we summarize the existing data about COVID-19 and other vaccine's efficacy in patients with NHL and propose multidisciplinary team-based recommendations for the management of vaccines in this specific group of patients.

Immune reconstitution, vaccine responses, and rituximab use after ex-vivo CD34-selected myeloablative allogenic hematopoietic cell transplantation

Myeloablative T cell depleted (CD34-selected) hematopoietic cell transplantation (HCT) is associated with less acute and chronic graft versus host disease (GVHD). We aimed to examine vaccine responses in relation to immune reconstitution and post HCT rituximab administration in this population. This single center retrospective study included 251 patients with hematological malignancies who received a first CD34-selected HCT between 2012 and 2015. Of 251 patients, 190 were alive 1 year after HCT. Among the entire population, 77 (30.7%) patients were vaccinated. After vaccine administration, 35/44 (80%), 30/75 (40%), 27/36 (75%), 33/65 (51%), 34/51 (51%), 22/28 (79%) and 20/34 (59%) of evaluable patients had protective antibody titers for haemophilus influenzae type B (Hib), Pneumococcus, Tetanus, Diphtheria, Pertussis, hepatitis A (HAV), and hepatitis B (HBV) respectively. Responders to the pneumococcal vaccine had a higher CD45RA T cell count than non responders, with 12/18 patients (66.7%) vs 11/32 (34.4%) p = 0.04. For pneumococcal vaccine, there was also a trend to higher total lymphocyte B cell count in responders vs non responders p = 0.06. Rituximab post HCT was given to 59/251 (23.5%) patients. No difference was found in immune reconstitution patterns for rituximab use between vaccine responders and not. Recipients of CD34-selected HCT may respond to vaccination, and T and B cell subsets could be useful to predict vaccine response.

SARS-CoV-2 Vaccine-Elicited Immunity after B Cell Depletion in Multiple Sclerosis

The impact of B cell deficiency on the humoral and cellular responses to SARS-CoV2 mRNA vaccination remains a challenging and significant clinical management question. We evaluated vaccine-elicited serological and cellular responses in 1) healthy individuals who were pre-exposed to SARS-CoV-2 (n = 21), 2) healthy individuals who received a homologous booster (mRNA, n = 19; or Novavax, n = 19), and 3) persons with multiple sclerosis on B cell depletion therapy (MS-αCD20) receiving mRNA homologous boosting (n = 36). Pre-exposure increased humoral and CD4 T cellular responses in immunocompetent individuals. Novavax homologous boosting induced a significantly more robust serological response than mRNA boosting. MS-α CD20 had an intact IgA mucosal response and an enhanced CD8 T cell response to mRNA boosting compared with immunocompetent individuals. This enhanced cellular response was characterized by the expansion of only effector, not memory, T cells. The enhancement of CD8 T cells in the setting of B cell depletion suggests a regulatory mechanism between B and CD8 T cell vaccine responses.

Initial Efficacy of the COVID-19 mRNA Vaccine Booster and Subsequent Breakthrough Omicron Variant Infection in Patients with B-Cell Non-Hodgkin's Lymphoma: A Single-Center Cohort Study

It has been suggested that the effect of coronavirus disease 2019 (COVID-19) booster vaccination in patients with B-cell non-Hodgkin's lymphoma (B-NHL) is inferior to that in healthy individuals. However, differences according to histological subtype or treatment status are unclear. In addition, there has been less research on patients who subsequently develop breakthrough infections. We investigated the effects of the first COVID-19 booster vaccination for patients with B-NHL and the clinical features of breakthrough infections in the Omicron variant era. In this study, B-NHL was classified into two histological subtypes: aggressive lymphoma and indolent lymphoma. Next, patients were subdivided according to treatment with anticancer drugs at the start of the first vaccination. We also examined the clinical characteristics and outcomes of patients who had breakthrough infections after a booster vaccination. The booster effect of the COVID-19 mRNA vaccine in patients with B-NHL varied considerably depending on treatment status at the initial vaccination. In the patient group at more than 1 year after the last anticancer drug treatment, regardless of the histological subtype, the booster effect was comparable to that in the healthy control group. In contrast, the booster effect was significantly poorer in the other patient groups. However, of the 213 patients who received the booster vaccine, 22 patients (10.3%) were infected with COVID-19, and 18 patients (81.8%) had mild disease; these cases included the patients who remained seronegative. Thus, we believe that booster vaccinations may help in reducing the severity of Omicron variant COVID-19 infection in patients with B-NHL.

Serological Responses and Predictive Factors of Booster COVID-19 Vaccines in Patients with Hematologic Malignancies

Patients with hematologic malignancies are reported to have a more severe course of coronavirus disease 2019 (COVID-19) and be less responsive to vaccination. In this prospective study, we aimed to evaluate the serological responses to booster COVID-19 vaccines of Taiwanese patients with hematologic malignancies and identify potential predictive markers for effective neutralizing immunity. This study enrolled 68 patients with hematologic malignancies and 68 age- and gender-matched healthy control subjects who received three doses of vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from 1 January 2022 to 31 October 2022. The SARS-CoV-2 immunoglobulin G (IgG) spike antibody level was measured with the Abbott assay. The effective neutralization capacity was defined as an anti-spike IgG level of ≥4160 AU/mL. Among the 68 patients with hematologic malignancies, 89.7% achieved seroconversion after booster doses. Seven patients with actively treated lymphoma remained seronegative and had the lowest humoral responses among patients with different types of hematologic malignancies. Despite comparable antibody titers between patients and healthy individuals, rates of effective neutralization (66.2% vs. 86.8%, respectively; p = 0.005) were significantly reduced in patients with hematologic malignancies. In a multivariate analysis, the independent predictors for effective neutralization were a lack of B-cell-targeted agents within six months of vaccination (odds ratio, 15.2; 95% confidence interval, 2.7-84.2; p = 0.002) and higher immunoglobulin levels (odds ratio, 4.4; 95% confidence interval, 1.3-14.7; p = 0.017). In conclusion, the majority of patients with hematologic malignancies achieved seroconversion after booster vaccination. Patients with ongoing B-cell depletion and hypogammaglobinemia were identified as having negative predictive markers for effective neutralization.

Vaccinations in hematological patients in the era of target therapies: Lesson learnt from SARS-CoV-2

Novel targeting agents for hematologic diseases often exert on- or off-target immunomodulatory effects, possibly impacting on response to anti-SARS-CoV-2 vaccinations and other vaccines. Agents that primarily affect B cells, particularly anti-CD20 monoclonal antibodies (MoAbs), Bruton tyrosine kinase inhibitors, and anti-CD19 chimeric antigen T-cells, have the strongest impact on seroconversion. JAK2, BCL-2 inhibitors and hypomethylating agents may hamper immunity but show a less prominent effect on humoral response to vaccines. Conversely, vaccine efficacy seems not impaired by anti-myeloma agents such as proteasome inhibitors and immunomodulatory agents, although lower seroconversion rates are observed with anti-CD38 and anti-BCMA MoAbs. Complement inhibitors for complement-mediated hematologic diseases and immunosuppressants used in aplastic anemia do not generally affect seroconversion rate, but the extent of the immune response is reduced under steroids or anti-thymocyte globulin. Vaccination is recommended prior to treatment or as far as possible from anti-CD20 MoAb (at least 6 months). No clearcut indications for interrupting continuous treatment emerged, and booster doses significantly improved seroconversion. Cellular immune response appeared preserved in several settings.

Rituximab versus obinutuzumab-based first-line chemoimmunotherapy for follicular lymphoma-a real-world multicenter retrospective cohort study

The GALLIUM study showed a progression-free survival advantage of 7% in favor of obinutuzumab vs. rituximab-based immunochemotherapies as first-line therapy in follicular lymphoma (FL) patients. Yet, the toxicity appears to be increased with obinutuzumab-based therapy. This is a multicenter retrospective-cohort study including adult FL patients comparing the toxicity of first-line rituximab vs. obinutuzumab-based chemo-immunotherapies (R and O groups, respectively). We compared the best standard-of-care therapy used per time period, before and after obinutuzumab approval. The primary outcome was any infection during induction and 6 months post-induction. Secondary outcomes included rates of febrile neutropenia, severe and fatal infections, other adverse events, and all-cause mortality. Outcomes were compared between groups. A total of 156 patients were included in the analysis, 78 patients per group. Most patients received bendamustine (59%) or CHOP (31.4%) as adjacent chemotherapy. Half of the patients received growth-factor prophylaxis. Overall, 69 patients (44.2%) experienced infections, and a total of 106 infectious episodes were recorded. Patients in the R and O groups had similar rates of any infection (44.8% and 43.5%, p = 1), severe infections (43.3% vs. 47.8%, p = 0.844), febrile neutropenia (15% vs. 19.6%, p = 0.606), and treatment discontinuation, as well as similar types of infections. No covariate was associated with infection in multivariable analysis. No statistically significant difference was evident in adverse events of grades 3-5 (76.9% vs. 82%, p = 0.427). To conclude, in this largest real-life study of first-line treated FL patients comparing R- to O-based therapy, we did not observe any difference in toxicity during the induction and 6 months post-induction period.

Adult Patients with Cancer Have Impaired Humoral Responses to Complete and Booster COVID-19 Vaccination, Especially Those with Hematologic Cancer on Active Treatment: A Systematic Review and Meta-Analysis

The exclusion of patients with cancer in clinical trials evaluating COVID-19 vaccine efficacy and safety, in combination with the high rate of severe infections, highlights the need for optimizing vaccination strategies. The aim of this study was to perform a systematic review and meta-analysis of the published available data from prospective and retrospective cohort studies that included patients with either solid or hematological malignancies according to the PRISMA Guidelines. A literature search was performed in the following databases: Medline (Pubmed), Scopus, Clinicaltrials.gov, EMBASE, CENTRAL and Google Scholar. Overall, 70 studies were included for the first and second vaccine dose and 60 studies for the third dose. The Effect Size (ES) of the seroconversion rate after the first dose was 0.41 (95%CI: 0.33-0.50) for hematological malignancies and 0.56 (95%CI: 0.47-0.64) for solid tumors. The seroconversion rates after the second dose were 0.62 (95%CI: 0.57-0.67) for hematological malignancies and 0.88 (95%CI: 0.82-0.93) for solid tumors. After the third dose, the ES for seroconversion was estimated at 0.63 (95%CI: 0.54-0.72) for hematological cancer and 0.88 (95%CI: 0.75-0.97) for solid tumors. A subgroup analysis was performed to evaluate potential factors affecting immune response. Production of anti-SARS-CoV-2 antibodies was found to be more affected in patients with hematological malignancies, which was attributed to the type of malignancy and treatment with monoclonal antibodies according to the subgroup analyses. Overall, this study highlights that patients with cancer present suboptimal humoral responses after COVID-19 vaccination. Several factors including timing of vaccination in relevance with active therapy, type of therapy, and type of cancer should be considered throughout the immunization process.

Anti-CD20 antibodies and bendamustine attenuate humoral immunity to COVID-19 vaccination in patients with B-cell non-Hodgkin lymphoma

Serologic responses of COVID-19 vaccine are impaired in patients with B-cell lymphoma, especially those who had recently been treated with anti-CD20 monoclonal antibodies. However, it is still unclear whether those patients develop an immune response following vaccination. We investigated the efficacy of vaccination against SARS-CoV-2 in 171 patients with B-cell non-Hodgkin lymphoma (B-NHL) who received two doses of an mRNA-based COVID-19 vaccine and we compared the efficacy of vaccination to that in 166 healthy controls. Antibody titers were measured 3 months after administration of the second vaccine dose. Patients with B-NHL showed a significantly lower seroconversion rate and a lower median antibody titer than those in healthy controls. The antibody titers showed correlations with the period from the last anti-CD20 antibody treatment to vaccination, the period from the last bendamustine treatment to vaccination and serum IgM level. The serologic response rates and median antibody titers were significantly different between diffuse large B-cell lymphoma (DLBCL) patients in whom anti-CD20 antibody treatment was completed within 9 months before vaccination and follicular lymphoma (FL) patients in whom anti-CD20 antibody treatment was completed within 15 months before vaccination. Moreover, the serologic response rates and median antibody titers were significantly different among FL patients in whom bendamustine treatment was completed within 33 months before vaccination. We demonstrated that B-NHL patients who were recently treated with anti-CD20 antibodies and bendamustine had a diminished humoral response to COVID-19 vaccination. UMIN 000,045,267.

Humoral response to mRNA-based COVID-19 vaccine and booster effect of a third dose in patients with mature T cell and NK-cell neoplasms

Patients with lymphoid malignancies have impaired humoral immunity caused by the disease itself and its treatment, placing them at risk for severe coronavirus disease-19 (COVID-19) and reduced response to vaccination. However, data for COVID-19 vaccine responses in patients with mature T cell and NK-cell neoplasms are very limited. In this study of 19 patients with mature T/NK-cell neoplasms, anti-severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike antibodies were measured at 3 months, 6 months, and 9 months after the second mRNA-based vaccination. At the time of the second and third vaccinations, 31.6% and 15.4% of the patients were receiving active treatment. All patients received the primary vaccine dose and the third vaccination rate was 68.4%. In patients with mature T/NK-cell neoplasms, both seroconversion rate (p < 0.01) and antibody titers (p < 0.01) after the second vaccination were significantly lower than those in healthy controls (HC). In individuals who received the booster dose, patients had significantly lower antibody titers than those in HC (p < 0.01); however, the seroconversion rate in patients was 100%, which was the same as that in HC. The booster vaccine resulted in a significant increase of antibodies in elderly patients who had shown a response that was inferior to that in younger patients after two doses of vaccination. Since higher antibody titers and higher seroconversion rate reduced the incidence of infection and mortality, vaccination more than three times may have the advantage for patients with mature T/NK-cell neoplasms, especially in elderly patients. Clinical trial registration number: UMIN 000,045,267 (August 26th, 2021), 000,048,764 (August 26th, 2022).

Management of patients with lymphoma and COVID-19: Narrative review and evidence-based practical recommendations

Patients with hematologic malignancies can be immunocompromized because of their disease, anti-cancer therapy, and concomitant immunosuppressive treatment. Furthermore, these patients are usually older than 60 years and have comorbidities. For all these reasons they are highly vulnerable to infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and have an increased risk of developing severe/critical Coronavirus disease 2019 (COVID-19) compared to the general population. Although COVID-19 vaccination has proven effective in reducing the incidence of severe/critical disease, vaccinated patients with lymphoma may not be protected as they often fail to develop a sufficient antiviral immune response. There is therefore an urgent need to address the management of patients with lymphoma and COVID-19 in the setting of the ongoing pandemic. Passive immunization with monoclonal antibodies against SARS-CoV-2 is a currently available complementary drug strategy to active vaccination for lymphoma patients, while monoclonal antibodies and antiviral drugs (remdesivir, ritonavir-boosted nirmatrelvir, and molnupiravir) have proven effective in preventing the progression to severe/critical COVID-19. In this narrative review we present the most recent data documenting the characteristics and outcomes of patients with concomitant lymphoma and COVID-19. Our ultimate goal is to provide practice-oriented guidance in the management of these vulnerable patients from diagnosis to treatment and follow-up of lymphoma. To this purpose, we will first provide an overview of the main data concerning prognostic factors and fatality rate of lymphoma patients who develop COVID-19; the outcomes of COVID-19 vaccination will also be addressed. We will then discuss current COVID-19 prophylaxis and treatment options for lymphoma patients. Finally, based on the literature and our multidisciplinary experience, we will summarize a set of indications on how to manage patients with lymphoma according to COVID-19 exposure, level of disease severity and former history of infection, as typically encountered in clinical practice.

Current approaches for the diagnosis and management of immune thrombocytopenia

Immune thrombocytopenia (ITP), is an acquired autoimmune disorder characterized by the destruction of platelets and megakaryocytes, resulting in thrombocytopenia (platelet count <100 × 10⁹/L). This review focuses on the diagnosis and current management of ITP. The diagnosis of ITP is based principally on the exclusion of other causes of isolated thrombocytopenia using patient history, physical examination, blood count, and evaluation of the peripheral blood film. The clinical treatment goals should be to resolve bleeding events and to prevent severe bleeding episodes. The platelet count should be improved to attain a minimum of > 20-30 × 10⁹/L. Therapy should be given as an inpatient in newly diagnosed ITP with a platelet count of > 20 × 10⁹/L or if there is active bleeding. Corticosteroids are considered the standard initial treatment for newly diagnosed patients. Subsequent medical therapies with robust evidence include thrombopoietin receptor agonists (TPO-RAs), rituximab and fostamatinib. Surgical therapy with splenectomy may be considered for patients failing medical therapy. The choice between therapy options is highly dependent upon patient values and preferences.

Impact of Treatment with Anti-CD20 Monoclonal Antibody on the Production of Neutralizing Antibody Against Anti-SARS-CoV-2 Vaccination in Mature B-Cell Neoplasms

Background and Purpose

Anti-CD20 monoclonal antibodies (MoAbs), rituximab (RIT), and obinutuzumab (OBZ) are the central components of immunochemotherapy for B-cell lymphoma (BCL). However, these agents potentially cause B-cell depletion, resulting in the impairment of antibody (Ab) production. During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the optimal prediction of Ab response against anti-SARS-CoV-2 vaccination is critically important in patients with BCL treated by B-cell depletion therapeutics to prevent coronavirus disease 2019 (COVID-19).

Patients and Methods

 We investigated the effect of using RIT and/or OBZ on the Ab response in 131 patients with various types of BCL who received the second SARS-CoV-2 mRNA vaccine either after, during, or before immunochemotherapy containing B-cell-depleting moiety between June and November 2021 at seven institutes belonging to the Kyoto Clinical Hematology Study Group. The SARS-Cov-2 neutralizing Ab (nAb) was measured from 14 to 207 days after the second vaccination dose using the iFlash3000 automatic analyzer and the iFlash-2019-nCoV Nab kit.

Results

Among 86 patients who received the vaccine within 12 months after B-cell depletion therapy, 8 (9.3%) were seropositive. In 30 patients who received the vaccine after 12 months from B-cell depletion therapy, 22 (73%) were seropositive. In 15 patients who were subjected to B-cell depletion therapy after vaccination, 2 (13%) were seropositive. The multivariate analysis indicated that an interval of 12 months between B-cell depletion therapy and the subsequent vaccination was significantly associated with effective Ab production. Receiver operating characteristic curve analysis identified the optimal threshold period after anti-CD20 MoAb treatment, which determines the seropositivity against SARS-CoV-2, to be 342 days.

Conclusion

The use of anti-CD20 MoAb within 12 months before vaccination is a critical risk for poor Ab response against anti-SARS-CoV-2 vaccination in patients with BCL.

Serological and cellular response to mRNA-SARS-CoV2 vaccine in patients with hematological lymphoid malignancies: Results of the study "Cervax"

messenger RNA (mRNA)-Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) vaccines such as BNT162b2 became available in late 2020, but hematological malignancy patients (HM pts) were not evaluated in initial registration trials. We hereby report the results of a prospective, unicentric, observational study Response to COVID-19 Vaccination in hEmatological malignancies (CERVAX) developed to assess the postvaccine serological and T-cell-mediated response in a cohort of SARS-CoV2-negative HM pts vaccinated with BNT162b2. Patients with lymphomas [non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL)], chronic lymphocytic leukemia (CLL), and multiple myeloma (MM); off-therapy for at least 3 months; in a watch-and-wait program; or in treatment with ibrutinib, venetoclax, and lenalidomide were included. Different time points were considered to assess the serological response to the vaccine: before the second dose (T1), at 3-6-12 months after the first dose (T2-3-4, respectively). Since March 2021, 39 pts have been enrolled: 15 (38%) NHL, 12 (31%) CLL, and 12 (31%) MM. There were 13 of the 39 pts (33%) seroconverted at T1; an increase of the serological response was registered after the second dose (T2) (22/39 pts, 56%) and maintained after 6 months (22/39 pts, 56%) and 12 months (24/39 pts, 61%) from the first dose (T3-T4, respectively). Non-serological responders at T4 were 7/39 (18%): 0/15 NHL, 1/12 MM (8%), and 6/12 CLL (50%). All of them were on therapy (one lenalidomide, three ibrutinib, and three venetoclax). SARS-CoV2-reactive T-cell analysis (interferon gamma release assays) was available since June 2022 and was evaluated at 12 months (T4) from the first dose of vaccine in 31/39 pts (79%). T-cell-mediated-responders were 17/31 (55%): most of them were NHL and MM (47%, 41% and 12% for NHL, MM, and CLL, respectively). Both serological and T-cell non-responders were represented by pts on active therapy (venetoclax/ibrutinib). During the period of observation, eight (20.5%) pts developed mild SARS-CoV2 infection; no coronavirus disease 19 (COVID-19)-related deaths or hospitalizations were registered. In conclusion, in our cohort of lymphoproliferative pts receiving BNT162b2, CLL diagnosis and venetoclax/ibrutinib seem to be related with a lower humoral or T-mediated response. Nevertheless, the efficacy of mRNA vaccine in HM pts and the importance to continue the vaccine program even in non-responders after the first dose are supported in our study by demonstrating that a humoral and T-cell-mediated seroconversion should be observed even in the subsets of heavily immunocompromised pts.

Immune Response to COVID-19 Vaccination in Hematologic Malignancies: A Mini-Review

The outbreak of the COVID-19 infection has led to the rapidity of vaccine usage in recent years. Emerging data indicate that the efficacy of vaccination against COVID-19 was about 95% in the general population, though its impact is impaired in patients with hematologic malignancies. As such, we decided to research the publications in which the authors reported the impacts of COVID-19 vaccination in patients suffering from hematologic malignancies. We concluded that patients with hematologic malignancies have lower responses, antibody titers as well as an impaired humoral response following vaccination, notably in patients with chronic lymphocytic leukemia (CLL) and lymphoma. Furthermore, it seems that the status of treatment can significantly affect the responses to the COVID-19 vaccination.

Immunogenicity and risks associated with impaired immune responses following SARS-CoV-2 vaccination and booster in hematologic malignancy patients: an updated meta-analysis

Patients with hematologic malignancies (HM) have demonstrated impaired immune responses following SARS-CoV-2 vaccination. Factors associated with poor immunogenicity remain largely undetermined. A literature search was conducted using PubMed, EMBASE, Cochrane, and medRxiv databases to identify studies that reported humoral or cellular immune responses (CIR) following complete SARS-CoV-2 vaccination. The primary aim was to estimate the seroconversion rate (SR) following complete SARS-CoV-2 vaccination across various subtypes of HM diseases and treatments. The secondary aims were to determine the rates of development of neutralizing antibodies (NAb) and CIR following complete vaccination and SR following booster doses. A total of 170 studies were included for qualitative and quantitative analysis of primary and secondary outcomes. A meta-analysis of 150 studies including 20,922 HM patients revealed a pooled SR following SARS-CoV-2 vaccination of 67.7% (95% confidence interval [CI], 64.8-70.4%; I² = 94%). Meta-regression analysis showed that patients with lymphoid malignancies, but not myeloid malignancies, had lower seroconversion rates than those with solid cancers (R² = 0.52, P < 0.0001). Patients receiving chimeric antigen receptor T-cells (CART), B-cell targeted therapies or JAK inhibitors were associated with poor seroconversion (R² = 0.39, P < 0.0001). The pooled NAb and CIR rates were 52.8% (95% CI; 45.8-59.7%, I² = 87%) and 66.6% (95% CI, 57.1-74.9%; I² = 86%), respectively. Approximately 20.9% (95% CI, 11.4-35.1%, I² = 90%) of HM patients failed to elicit humoral and cellular immunity. Among non-seroconverted patients after primary vaccination, only 40.5% (95% CI, 33.0-48.4%; I² = 87%) mounted seroconversion after the booster. In conclusion, HM patients, especially those with lymphoid malignancies and/or receiving CART, B-cell targeted therapies, or JAK inhibitors, showed poor SR after SARS-CoV-2 vaccination. A minority of patients attained seroconversion after booster vaccination. Strategies to improve immune response in these severely immunosuppressed patients are needed.

Antibody response after vaccination against SARS-CoV-2 in adults with hematological malignancies: a systematic review and meta-analysis

Vaccines against SARS-CoV-2 have shown remarkable efficacy and thus constitute an important preventive option against coronavirus disease 2019 (COVID-19), especially in fragile patients. We aimed to systematically analyze the outcomes of patients with hematological malignancies who received vaccination and to identify specific groups with differences in outcomes. The primary end point was antibody response after full vaccination (2 doses of mRNA or one dose of vector- based vaccines). We identified 49 studies comprising 11,086 individuals. Overall risk of bias was low. The pooled response for hematological malignancies was 64% (95% confidence interval [CI]: 59-69; I²=93%) versus 96% (95% CI: 92-97; I²=44%) for solid cancer and 98% (95% CI: 96-99; I²=55%) for healthy controls (P<0.001). Outcome was different across hematological malignancies (P<0.001). The pooled response was 50% (95% CI: 43-57; I²=84%) for chronic lymphocytic leukemia, 76% (95% CI: 67-83; I²=92%) for multiple myeloma, 83% (95% CI: 69-91; I²=85%) for myeloproliferative neoplasms, 91% (95% CI: 82-96; I²=12%) for Hodgkin lymphoma, and 58% (95% CI: 44-70; I²=84%) for aggressive and 61% (95% CI: 48-72; I²=85%) for indolent non-Hodgkin lymphoma. The pooled response for allogeneic and autologous hematopoietic cell transplantation was 82% and 83%, respectively. Being in remission and prior COVID-19 showed significantly higher responses. Low pooled response was identified for active treatment (35%), anti-CD20 therapy ≤1 year (15%), Bruton kinase inhibition (23%), venetoclax (26%), ruxolitinib (42%), and chimeric antigen receptor T-cell therapy (42%). Studies on timing, value of boosters, and long-term efficacy are needed. This study is registered with PROSPERO (clinicaltrials gov. Identifier: CRD42021279051).

A systematic review and meta-analysis of immune response against first and second doses of SARS-CoV-2 vaccines in adult patients with hematological malignancies

BACKGROUND

Cancer patients particularly those with hematological malignancies are at higher risk of affecting by severe coronavirus disease 2019 (COVID-19). Due to the immunocompromised nature of the disease and the immunosuppressive treatments, they are more likely to develop less antibody protection; therefore, we aimed to evaluate the immunogenicity of COVID-19 vaccines in patients with hematological malignancies.

METHODS

A comprehensive systematic search was conducted in PubMed, Scopus, and Web of Science databases, as well as Google scholar search engine as of December 10, 2021. Our primary outcomes of interest comprised of estimating the antibody seropositive rate following COVID-19 vaccination in patients with hematological malignancies and to compare it with those who were affected by solid tumors or healthy subjects. The secondary outcomes were to assess the vaccine's immunogenicity based on different treatments, status of the disease, and type of vaccine. After the two-step screening, the data were extracted and the summary measures were calculated using a random-effect model.

RESULTS

A total of 82 articles recording 13,804 patients with a diagnosis of malignancy were included in the present review. The seropositive rates in patients with hematological malignancies after first and second vaccine doses were 30.0% (95% confidence interval (95%CI): 11.9-52.0) and 62.3% (95%CI 56.0-68.5), respectively. These patients were less likely to develop antibody response as compared to cases with solid tumors (RR 0.73, 95%CI 0.67-0.79) and healthy subjects (RR 0.62, 95%CI 0.54-0.71) following complete immunization. Chronic lymphocytic leukemia (CLL) patients had the lowest response rate among all subtypes of hematological malignancies (first dose: 22.0%, 95%CI 13.5-31.8 and second dose: 47.8%, 95%CI 41.2-54.4). Besides, anti-CD20 therapies (5.7%, 95%CI 2.0-10.6) and bruton's tyrosine kinase inhibitors (26.8%, 95%CI 16.9-37.8) represented the lowest seropositiveness post first and second doses, respectively. Notably, patients who were in active status of disease showed lower antibody detection rate compared to those on remission status (RR 0.87, 95%CI 0.76-0.99). Furthermore, lower rate of seropositivity was found in patients received BNT162.b2 compared to ones who received mRNA-1273 (RR 0.89, 95%CI 0.79-0.99).

CONCLUSION

Our findings highlight the substantially low rate of seroprotection in patients with hematological malignancies with a wide range of rates among disease subgroups and different treatments; further highlighting the fact that booster doses might be acquired for these patients to improve immunity against SARS-CoV-2.

COVID-19 mRNA Vaccine in Patients With Lymphoid Malignancy or Anti-CD20 Antibody Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

The humoral response to vaccination in individuals with lymphoid malignancies or those undergoing anti-CD20 antibody therapy is impaired, but details of the response to mRNA vaccines to protect against COVID-19 remain unclear. This systematic review and meta-analysis aimed to characterize the response to COVID-19 mRNA vaccines in patients with lymphoid malignancies or those undergoing anti-CD20 antibody therapy.

MATERIALS AND METHODS

A literature search retrieved 52 relevant articles, and random-effect models were used to analyze humoral and cellular responses.

RESULTS

Lymphoid malignancies and anti-CD20 antibody therapy for non-malignancies were significantly associated with lower seropositivity rates (risk ratio 0.60 [95% CI 0.53-0.69]; risk ratio 0.45 [95% CI 0.39-0.52], respectively). Some subtypes (chronic lymphocytic leukemia, treatment-naïve chronic lymphocytic leukemia, myeloma, and non-Hodgkin's lymphoma) exhibited impaired humoral response. Anti-CD20 antibody therapy within 6 months of vaccination decreased humoral response; moreover, therapy > 12 months before vaccination still impaired the humoral response. However, anti-CD20 antibody therapy in non-malignant patients did not attenuate T cell responses.

CONCLUSION

These data suggest that patients with lymphoid malignancies or those undergoing anti-CD20 antibody therapy experience an impaired humoral response, but cellular response can be detected independent of anti-CD20 antibody therapy. Studies with long-term follow-up of vaccine effectiveness are warranted (PROSPERO registration number: CRD42021265780).

COVID-19 Vaccines and Immunosuppressed Patients With Cancer: Critical Considerations

BACKGROUND

&nbsp;Patients with cancer are highly vulnerable to COVID-19 because of immunosuppression from diseases and treatments. Emerging data characterize the impact of COVID-19 vaccines related to cancer malignancies and treatments.

OBJECTIVES

&nbsp;This article provides a clinical foundation on the immune response to the COVID-19 vaccine associated with the impact of cancer and its related treatments. It reviews strategies for vaccine scheduling, Centers for Disease Control and Prevention recommendations, and nursing considerations when administering the vaccine to immunosuppressed patients.

METHODS

&nbsp;Research studies about immune responses to COVID-19 vaccines among immunosuppressed patients with hematologic and solid tumor malignancies were summarized.

FINDINGS

&nbsp;Studies about the humoral immune responses of patients with cancer to COVID-19 vaccines help guide vaccination planning for this population. Critical nursing considerations for patients with cancer receiving COVID-19 vaccination are integral to the provision of optimal clinical oncology care during the pandemic.

Seroconversion and outcomes after initial and booster COVID-19 vaccination in adults with hematologic malignancies

Background

Patients with hematologic malignancies have impaired humoral immunity secondary to their malignancy and its treatment, placing them at risk of severe coronavirus disease‐19 (COVID‐19) infection and reduced response to vaccination.

Methods

The authors retrospectively analyzed serologic responses to initial and booster COVID‐19 vaccination in 378 patients with hematologic malignancy and subsequently tracked COVID‐19–related outcomes.

Results

Seroconversion occurred in 181 patients (48%) after initial vaccination; patients who had active malignancy or those who were recently treated with a B‐cell–depleting monoclonal antibody had the lowest rates of seroconversion. For initial nonresponders to vaccination, seroconversion after a booster dose occurred in 48 of 85 patients (56%). The seroconversion rate after the booster was similar for patients on (53%) and off (58%) active therapy (p = .82). Thirty‐three patients (8.8%) developed a COVID‐19 infection, and there were three COVID‐19–related deaths (0.8%). Although no significant association was observed between postvaccination seroconversion and the incidence of COVID‐19 infection, no patient with seroconversion died from COVID‐19, and no patient who received tixagevimab/cilgavimab (N = 25) was diagnosed with a COVID‐19 infection.

Conclusions

Booster vaccinations can promote seroconversion in a significant proportion of patients who are seronegative after the initial vaccination course regardless of the specific vaccine or on/off treatment status at the time of revaccination. Although postvaccination seroconversion may not be associated with a decrease in any (including asymptomatic) COVID‐19 infection, the authors' experience suggested that effective vaccination (including a booster), supplemented by passive immunization using tixagevimab/cilgavimab in case of lack of seroconversion, effectively eliminated the risk of COVID‐19 death in the otherwise high‐risk population.

Lay summary

Patients with hematologic malignancy, especially lymphoma, have an impaired response to coronavirus disease 2019 (COVID‐19) vaccination.

In this single‐institution review, less than one half of the patients studied made detectable antibodies.

For those who did not make detectable antibodies after initial vaccination, over one half (65%) were able to produce antibodies after booster vaccination.

By the end of February 2022, 33 of the original 378 patients had a documented COVID‐19 infection.

The only deaths from COVID‐19 were in those who had undetectable antibodies, and no patient who received prophylactic antibody therapy developed a COVID‐19 infection.

Hematologic malignancies and their treatments impaired humoral immunity from coronavirus disease 2019 vaccination, and booster vaccine overcame a lack of initial response in 58% of patients, including 63% those on active therapy. The findings indicated that booster vaccinations should be strongly encouraged; however, even with boosters, many remain unprotected, which should inform infection prevention and treatment strategies.

Antibody Response to SARS-CoV-2 Vaccination in Patients With Lymphoproliferative Disorders and Plasma Cell Dyscrasias: Anti-Lymphoma Therapy as a Predictive Biomarker of Response to Vaccination

We retrospectively analyzed SARS-CoV-2 vaccination antibody responses in a cohort of 273 patients with lymphoproliferative disorders or plasma cell dyscrasias who were seen at a single tertiary cancer center. Semi-quantitative anti-spike protein serologic testing was performed with enzyme immunoassay method. We found that the antibody response rate to SARS-CoV-2 vaccination was 74.7% in our patient cohort with no difference based on gender, age or race. The highest response rate was found in patients with Multiple Myeloma (MM) (95.5%). The response rates found in Diffuse Large B-Cell Lymphoma (DLBCL), Chronic Lymphocytic Leukemia (CLL), and Low-Grade Non-Hodgkin Lymphoma (LG-NHL) were 73.2%, 61.5% and 53% respectively. We also evaluated the effects of receiving active chemo-immunotherapy on SARS-CoV-2 vaccination antibody response. We found that the patients on treatment had lower response than the patients off treatment (62.1% versus 84.4% p<0.001). Thirty-four of 58 LG-NHL patients were receiving anti-lymphoma treatment with a lower SARS-CoV-2 vaccination response as compared to the patients who were not on treatment (29.4% v 87.5% p<0.001). We observed a similar pattern in CLL patients receiving treatment (48.1 v 76.0 p:0.049). We found that only disease type and treatment status (on-treatment vs. off- treatment), but not gender, age or race were significant predictors of non-response in the multivariable logistic regression model. The interaction between disease type and treatment status was not statistically significant by multivariate analysis. In conclusion, receiving anti-cancer treatment was found to play a significant role in decreasing the response to COVID-19 vaccination.

Seroconversion following COVID-19 vaccination: can we optimize protective response in CD20-treated individuals?

Although there is an ever-increasing number of disease-modifying treatments for relapsing multiple sclerosis (MS), few appear to influence coronavirus disease 2019 (COVID-19) severity. There is concern about the use of anti-CD20-depleting monoclonal antibodies, due to the apparent increased risk of severe disease following severe acute respiratory syndrome corona virus two (SARS-CoV-2) infection and inhibition of protective anti-COVID-19 vaccine responses. These antibodies are given as maintenance infusions/injections and cause persistent depletion of CD20+ B cells, notably memory B-cell populations that may be instrumental in the control of relapsing MS. However, they also continuously deplete immature and mature/naïve B cells that form the precursors for infection-protective antibody responses, thus blunting vaccine responses. Seroconversion and maintained SARS-CoV-2 neutralizing antibody levels provide protection from COVID-19. However, it is evident that poor seroconversion occurs in the majority of individuals following initial and booster COVID-19 vaccinations, based on standard 6 monthly dosing intervals. Seroconversion may be optimized in the anti-CD20-treated population by vaccinating prior to treatment onset or using extended/delayed interval dosing (3-6 month extension to dosing interval) in those established on therapy, with B-cell monitoring until (1-3%) B-cell repopulation occurs prior to vaccination. Some people will take more than a year to replete and therefore protection may depend on either the vaccine-induced T-cell responses that typically occur or may require prophylactic, or rapid post-infection therapeutic, antibody or small-molecule antiviral treatment to optimize protection against COVID-19. Further studies are warranted to demonstrate the safety and efficacy of such approaches and whether or not immunity wanes prematurely as has been observed in the other populations.

Can B cell-deficient patients rely on COVID-19 vaccine-induced T cell immunity?

Anti‐CD20 antibody treatments prevent humoral responses to vaccines against severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) vaccines, but the nature of T‐cell responses in this setting is less well understood. Riise et al. assess vaccine‐induced epitope‐specific CD8 T cell responses in patients with lymphoma recently treated with rituximab and find a wide range of responses, with the most recently treated patients frequently failing to respond, while others exhibit responses stronger than healthy controls. They suggest these epitopes among others could be used in a T cell‐targeted vaccine, and such strategies are indeed in clinical trials now.

Commentary on: Riise J, et al. Rituximab‐treated patients with lymphoma develop strong CD8 T‐cell responses following COVID‐19 vaccination. Br J Haematol. 2022;197:697‐708

Managing hematological cancer patients during the COVID-19 pandemic: an ESMO-EHA Interdisciplinary Expert Consensus

BACKGROUND

The COVID-19 pandemic has created enormous challenges for the clinical management of patients with hematological malignancies (HMs), raising questions about the optimal care of this patient group.

METHODS

This consensus manuscript aims at discussing clinical evidence and providing expert advice on statements related to the management of HMs in the COVID-19 pandemic. For this purpose, an international consortium was established including a steering committee, which prepared six working packages addressing significant clinical questions from the COVID-19 diagnosis, treatment, and mitigation strategies to specific HMs management in the pandemic. During a virtual consensus meeting, including global experts and lead by the European Society for Medical Oncology and the European Hematology Association, statements were discussed and voted upon. When a consensus could not be reached, the panel revised statements to develop consensual clinical guidance.

RESULTS AND CONCLUSION

The expert panel agreed on 33 statements, reflecting a consensus, which will guide clinical decision making for patients with hematological neoplasms during the COVID-19 pandemic.

COVID-19 vaccination in cancer patients: a narrative review

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected over 220 million individuals worldwide, and has been shown to cause increased disease severity and mortality in patients with active cancer versus healthy individuals. Vaccination is important in reducing COVID-19-associated morbidity and mortality. Thus, the aim of this article was to review the existing knowledge on effectiveness, immunogenicity and safety of COVID-19 vaccines in patients with cancer. Fifty-four articles were included following a search of PubMed and Google Scholar databases for studies published between January 2020 and September 2021 that investigated humoral and cell-mediated immune responses following COVID-19 vaccination in patients with cancer. Immunogenicity of vaccines was found to be lower in patients with cancer versus healthy individuals, and humoral immune responses were inferior in those with haematological versus solid cancers. Patient-, disease-, and treatment-related factors associated with poorer vaccine responses should be identified and corrected or mitigated when possible. Consideration should be given to offering patients with cancer second doses of COVID vaccine at shorter intervals than in healthy individuals. Patients with cancer warrant a third vaccine dose and must be prioritized in vaccination schedules. Vaccine adverse effect profiles are comparable between patients with cancer and healthy individuals.

CD20-Targeted Therapy Ablates De Novo Antibody Response to Vaccination but Spares Preestablished Immunity

To obtain a deeper understanding of poor responses to COVID-19 vaccination in patients with lymphoma, we assessed blocking antibodies, total anti-spike IgG, and spike-specific memory B cells in the peripheral blood of 126 patients with lymphoma and 20 age-matched healthy controls 1 and 4 months after COVID-19 vaccination. Fifty-five percent of patients developed blocking antibodies postvaccination, compared with 100% of controls. When evaluating patients last treated from days to nearly 18 years prior to vaccination, time since last anti-CD20 was a significant independent predictor of vaccine response. None of 31 patients who had received anti-CD20 treatment within 6 months prior to vaccination developed blocking antibodies. In contrast, patients who initiated anti-CD20 treatment shortly after achieving a vaccine-induced antibody response tended to retain that response during treatment, suggesting a policy of immunizing prior to treatment whenever possible.

SIGNIFICANCE

In a large cohort of patients with B-cell lymphoma, time since anti-CD20 treatment was an independent predictor of neutralizing antibody response to COVID-19 vaccination. Comparing patients who received anti-CD20 treatment before or after vaccination, we demonstrate that vaccinating first can generate an antibody response that endures through anti-CD20-containing treatment. This article is highlighted in the In This Issue feature, p. 85.

Humoral response to mRNA-based COVID-19 vaccine in patients with myeloid malignancies

Data on the response to the COVID‐19 vaccine in patients with myeloid malignancy, who are at severe risk in case of infection, have not emerged. In a study of 69 patients with myeloid malignancies, including 46 patients with acute myeloid leukaemia (AML) and 23 patients with myelodysplastic syndrome (MDS), anti‐spike SARS‐CoV‐2 antibody titres were measured 3 months after the second mRNA‐based vaccination. Seroconversion rates for AML and MDS were 94.7% and 100% respectively, with no significant difference from healthy controls (HCs). Patients with MDS showed a significantly lower antibody titre than that in HCs or AML patients. In AML patients, the antibody titres were comparable to those in HCs when treatment was completed, but lower in patients under maintenance therapy. The response to COVID‐19 vaccine appears to be related to disease and treatment status. Patients with myeloid malignancies may be more responsive to vaccines than patients with lymphoid malignancies.

Low clinical protective response to SARS-CoV-2 mRNA COVID-19 vaccine in patients with multiple myeloma

We conducted a prospective, three-center, observational study in Japan to evaluate the prevalence of seropositivity and clinically protective titer after coronavirus disease 2019 vaccination in patients with plasma cell dyscrasia(PCD). Two-hundred sixty-nine patients with PCD [206 symptomatic multiple myeloma (MM)] were evaluated. Seropositivity was observed in 88.7% and a clinically protective titer in 38.3% of MM patients, both of which were significantly lower than those of healthy controls. Patients receiving anti-CD38 antibodies had much lower antibody titers, but antibody titers recovered in those who underwent a wash-out period before vaccine administration. Older age (≥65), anti-CD38 antibody administration, immunomodulatory drugs use, lymphopenia (<1000/μL), and lower polyclonal IgG (<550 mg/dL) had a negative impact for the sufficient antibody production according to multivariate analysis. Patients with clinically protective titer had a significantly higher number of CD19+ lymphocytes than those with lower antibody responses (114 vs. 35/μL, p = 0.016). Our results suggested that patients with PCD should be vaccinated, and that the ideal protocol is to temporarily interrupt anti-CD38 antibody therapy for a “wash-out” period of a few months, followed by a (booster) vaccine after the B-cells have recovery.

Immunological and clinical efficacy of COVID-19 vaccines in immunocompromised populations: a systematic review

BACKGROUND

Available data show that COVID-19 vaccines may be less effective in immunocompromised populations, who are at increased risk of severe COVID-19.

OBJECTIVES

We conducted a systematic review of literature to assess immunogenicity, efficacy and effectiveness of COVID-19 vaccines in immunocompromised populations.

DATA SOURCES

We searched Medline and Embase databases.

STUDY ELIGIBILITY CRITERIA, PATIENTS, INTERVENTIONS

We included studies of COVID-19 vaccines after complete vaccination in immunocompromised patients until 31 August 2021. Studies with <10 patients, safety data only and case series of breakthrough infections were excluded.

METHODS

Risk of bias was assessed via the tool developed by the National Institutes of Health on interventional and observational studies. Immunogenicity was assessed through non-response rate defined as no anti-SARS-CoV-2 spike protein antibodies, efficacy and effectiveness by the relative reduction in risk of SARS-CoV-2 infection or COVID-19. We collected factors associated with the risk of non-response. We presented collected data by immunosuppression type.

RESULTS

We screened 5917 results, included 162 studies. There were 157 on immunogenicity in 25 209 participants, including 7835 cancer or haematological malignancy patients (31.1%), 6302 patients on dialysis (25.0%), 5974 solid organ transplant recipients (23.7%) and 4680 immune-mediated disease patients (18.6%). Proportion of non-responders seemed higher among solid organ transplant recipients (range 18-100%) and patients with haematological malignancy (range 14-61%), and lower in patients with cancer (range 2-36%) and patients on dialysis (range 2-30%). Risk factors for non-response included older age, use of corticosteroids, immunosuppressive or anti-CD20 agent. Ten studies evaluated immunogenicity of an additional dose. Five studies evaluated vaccine efficacy or effectiveness: three on SARS-CoV-2 infection (range 71-81%), one on COVID-19-related hospitalization (62.9%), one had a too small sample size.

CONCLUSIONS

This systematic review highlights the risk of low immunogenicity of COVID-19 vaccines in immunocompromised populations, especially solid organ transplant recipients and patients with haematological malignancy. Despite lack of vaccine effectiveness data, enhanced vaccine regimens may be necessary.

Humoral and cellular immune responses on SARS-CoV-2 vaccines in patients with anti-CD20 therapies: a systematic review and meta-analysis of 1342 patients

BACKGROUND

Immune responses on SARS-CoV-2 vaccination in patients receiving anti-CD20 therapies are impaired but vary considerably. We conducted a systematic review and meta-analysis of the literature on SARS-CoV-2 vaccine induced humoral and cell-mediated immune response in patients previously treated with anti-CD20 antibodies.

METHODS

We searched PubMed, Embase, Medrxiv and SSRN using variations of search terms 'anti-CD20', 'vaccine' and 'COVID' and included original studies up to 21 August 2021. We excluded studies with missing data on humoral or cell-mediated immune response, unspecified methodology of response testing, unspecified timeframes between vaccination and blood sampling or low number of participants (≤3). We excluded individual patients with prior COVID-19 or incomplete vaccine courses. Primary endpoints were humoral and cell-mediated immune response rates. Subgroup analyses included time since anti-CD20 therapy, B cell depletion and indication for anti-CD20 therapy. We used random-effects models of proportions.

FINDINGS

Ninety studies were assessed. Inclusion criteria were met by 23 studies comprising 1342 patients. Overall rate of humoral response was 0.40 (95% CI 0.35 to 0.47). Overall rate of cell-mediated immune responses was 0.71 (95% CI 0.57 to 0.87). A time interval >6 months since last anti-CD20 therapy was associated with higher humoral response rates with 0.63 (95% CI 0.53 to 0.72) versus <6 months 0.2 (95% CI 0.03 to 0.43); p=0<01. Similarly, patients with circulating B cells more frequently showed humoral responses. Anti-CD20-treated kidney transplant recipients showed lower humoral response rates than patients with haematological malignancies or autoimmune disease.

INTERPRETATION

Patients on anti-CD20 therapies can develop humoral and cell-mediated immune responses after SARS-CoV-2 vaccination, but subgroups such as kidney transplant recipients or those with very recent therapy and depleted B cell are at high risk for non-seroconversion and should be individually assessed for personalised SARS-CoV-2 vaccination strategies. Potential limitations are small patient numbers and heterogeneity of studies included.

FUNDING

This study was funded by Bern University Hospital.

A prognostic model for patients with lymphoma and COVID-19: a multicentre cohort study

Lymphoma represents a heterogeneous hematological malignancy (HM), which is characterized by severe immunosuppression. Patients diagnosed of coronavirus disease 2019 (COVID-19) during the course of HM have been described to have poor outcome, with only few reports specifically addressing lymphoma patients. Here, we investigated the clinical behavior and clinical parameters of a large multicenter cohort of adult patients with different lymphoma subtypes, with the aim of identifying predictors of death. The study included 856 patients, of whom 619 were enrolled prospectively in a 1-year frame and were followed-up for a median of 66 days (range 1-395). Patients were managed as outpatient (not-admitted cohort, n = 388) or required hospitalization (n = 468), and median age was 63 years (range 19-94). Overall, the 30- and 100-days mortality was 13% (95% confidence interval (CI), 11% to 15%) and 23% (95% CI, 20% to 27%), respectively. Antilymphoma treatment, including anti-CD20 containing regimens, did not impact survival. Patients with Hodgkin's lymphoma had the more favorable survival, but this was partly related to significantly younger age. The time interval between lymphoma diagnosis and COVID-19 was inversely related to mortality. Multivariable analysis recognized 4 easy-to-use factors (age, gender, lymphocyte, and platelet count) that were associated with risk of death, both in the admitted and in the not-admitted cohort (HR 3.79 and 8.85 for the intermediate- and high-risk group, respectively). Overall, our study shows that patients should not be deprived of the best available treatment of their underlying disease and indicates which patients are at higher risk of death. This study was registered with ClinicalTrials.gov, NCT04352556.

Antibody response after vaccination against SARS-CoV-2 in adults with hematological malignancies: a systematic review and meta-analysis

Vaccines against SARS-CoV-2 have shown remarkable efficacy and thus constitute an important preventive option against coronavirus disease 2019 (COVID-19), especially in fragile patients. We aimed to systematically analyze the outcomes of patients with hematological malignancies who received vaccination and to identify specific groups with differences in outcomes. The primary end point was antibody response after full vaccination (2 doses of mRNA or one dose of vectorbased vaccines). We identified 49 studies comprising 11,086 individuals. Overall risk of bias was low. The pooled response for hematological malignancies was 64% (95% confidence interval [CI]: 59-69; I²=93%) versus 96% (95% CI: 92-97; I²=44%) for solid cancer and 98% (95% CI: 96-99; I²=55%) for healthy controls (P<0.001). Outcome was different across hematological malignancies (P<0.001). The pooled response was 50% (95% CI: 43-57; I²=84%) for chronic lymphocytic leukemia, 76% (95% CI: 67-83; I²=92%) for multiple myeloma, 83% (95% CI: 69-91; I²=85%) for myeloproliferative neoplasms, 91% (95% CI: 82-96; I²=12%) for Hodgkin lymphoma, and 58% (95% CI: 44-70; I²=84%) for aggressive and 61% (95% CI: 48-72; I²=85%) for indolent non-Hodgkin lymphoma. The pooled response for allogeneic and autologous hematopoietic cell transplantation was 82% and 83%, respectively. Being in remission and prior COVID-19 showed significantly higher responses. Low pooled response was identified for active treatment (35%), anti-CD20 therapy ≤1 year (15%), Bruton kinase inhibition (23%), venetoclax (26%), ruxolitinib (42%), and chimeric antigen receptor T-cell therapy (42%). Studies on timing, value of boosters, and long-term efficacy are needed. This study is registered with PROSPERO (clinicaltrials gov. Identifier: CRD42021279051).

How to Provide the Needed Protection from COVID-19 to Patients with Hematologic Malignancies

Patients with hematologic malignancies are particularly vulnerable to COVID-19 infections, and upon a pooled data analysis of 24 publications, there is evidence that they have suboptimal antibody responses to COVID-19 vaccination and boosters. To provide them the needed additional protection from COVID-19, it is imperative to achieve a 100% full immunization rate in health care workers and adult caretakers, and to foster research to test higher doses and repeated rounds of COVID-19 vaccines and the use of passive immune prophylaxis and therapy.

Humoral serological response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation

Objectives

To assess the humoral immune response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation (HCT).

Methods

This is a prospective cohort study. The SARS-CoV-2 IgGII Quant (Abbott©) assay was performed 4–6 weeks after the second BNT162b2 vaccine for quantitative measurement of anti-spike antibodies.

Results

The cohort included 106 adult patients. Median time from HCT to vaccination was 42 (range 4–439) months. Overall, 15/106 (14%, 95% confidence interval (CI) 7–21%) were seronegative despite vaccination, 14/52 patients on immunosuppression (27%, 95%CI 19–35%) compared to only 1/54 patients off immunosuppression (1.8%, 95%CI 1–4%) (p 0.0002). The proportion of seronegative patients declined with time; it was 46% (6/13) during the first year, 12.5% (3/24) during the second year and 9% (6/69) beyond 2 years from transplant. Patients with acute graft-versus-host disease (GVHD) (odds ratio (OR) 3.3, 95%CI 0.97–11.1, p 0.06) and moderate to severe chronic GVHD (OR 5.9, 95%CI 1.2–29, p 0.03) were more likely to remain seronegative. Vaccination was well tolerated by most patients. However, 7% (7/106) reported that GVHD-related symptoms worsened within days following vaccination.

Conclusion

A significant proportion of allogeneic HCT recipients receiving immunosuppression demonstrated an inadequate humoral response to the BNT162b2 vaccine. These patients should be recognized and instructed to take appropriate precautions. Recipients who were off immunosuppression had a humoral response that was comparable to that of the general population.