Pneumococcal conjugate vaccine triggers a better immune response than pneumococcal polysaccharide vaccine in patients with chronic lymphocytic leukemia A randomized study by the Swedish CLL group

Vaccination of Adults With Cancer: ASCO Guideline

PURPOSE

To guide the vaccination of adults with solid tumors or hematologic malignancies.

METHODS

A systematic literature review identified systematic reviews, randomized controlled trials (RCTs), and nonrandomized studies on the efficacy and safety of vaccines used by adults with cancer or their household contacts. This review builds on a 2013 guideline by the Infectious Disease Society of America. PubMed and the Cochrane Library were searched from January 1, 2013, to February 16, 2023. ASCO convened an Expert Panel to review the evidence and formulate recommendations.

RESULTS

A total of 102 publications were included in the systematic review: 24 systematic reviews, 14 RCTs, and 64 nonrandomized studies. The largest body of evidence addressed COVID-19 vaccines.

RECOMMENDATIONS

The goal of vaccination is to limit the severity of infection and prevent infection where feasible. Optimizing vaccination status should be considered a key element in the care of patients with cancer. This approach includes the documentation of vaccination status at the time of the first patient visit; timely provision of recommended vaccines; and appropriate revaccination after hematopoietic stem-cell transplantation, chimeric antigen receptor T-cell therapy, or B-cell-depleting therapy. Active interaction and coordination among healthcare providers, including primary care practitioners, pharmacists, and nursing team members, are needed. Vaccination of household contacts will enhance protection for patients with cancer. Some vaccination and revaccination plans for patients with cancer may be affected by the underlying immune status and the anticancer therapy received. As a result, vaccine strategies may differ from the vaccine recommendations for the general healthy adult population vaccine.Additional information is available at www.asco.org/supportive-care-guidelines.

Prevention and management of infectious complications in patients with chronic lymphocytic leukemia (CLL) treated with BTK and BCL-2 inhibitors, focus on current guidelines

CLL is associated with an increased risk of infectious complications. Treatment with BTK or BCL-2 inhibitors does not seem to increase significantly the risk of opportunistic infections, but the role of combination therapies including BTK and/or BCL-2 inhibitors remains to be established. Various infectious complications can be successfully prevented with appropriate risk management strategies. In this paper we reviewed the international guidelines on prevention and management of infectious complications in patients with CLL treated with BTK or BCL-2 inhibitors. Universal pharmacological anti-herpes, antibacterial or antifungal prophylaxis is not warranted. Reactivation of HBV should be prevented in HBsAg-positive subjects. For HBsAg-negative/HBcAb-positive patients recommendations differ, but in case of combination treatment should follow those for other, particularly anti-CD20, agent. Immunization should be provided preferably before the onset of treatment. Immunoglobulin therapy has favourable impact on morbidity but not mortality in patients with hypogammaglobulinemia and severe or recurrent infections. Lack of high-quality data and heterogeneity of patients or protocols included in the studies might explain differences among the main guidelines. Better data collection is warranted.

Vaccinations in patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by immune dysfunction resulting in heightened susceptibility to infections and elevated rates of morbidity and mortality. A key strategy to mitigate infection-related complications has been immunization against common pathogens. However, the immunocompromised status of CLL patients poses challenges in eliciting an adequate humoral and cellular immune response to vaccination. Most CLL-directed therapy disproportionately impairs humoral immunity. Vaccine responsiveness also depends on the phase and type of immune response triggered by immunization. In this review, we discuss the immune dysfunction, vaccine responsiveness, and considerations for optimizing vaccine response in patients with CLL.

Chronic lymphocytic leukaemia Australasian consensus practice statement

Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in Australia and New Zealand (ANZ). Considerable changes to diagnostic and management algorithms have occurred within the last decade. The availability of next-generation sequencing and measurable residual disease assessment by flow cytometry allow for advanced prognostication and response assessments. Novel therapies, including inhibitors of Bruton's tyrosine kinase (BTKi) and B-cell lymphoma 2 (BCL2) inhibitors, have transformed the treatment landscape for both treatment-naïve and relapsed/refractory disease, particularly for patients with high-risk genetic aberrations. Recommendations regarding appropriate supportive management continue to evolve, and special considerations are required for patients with CLL with respect to the global SARS-CoV-2 pandemic. The unique funding and treatment environments in Australasia highlight the need for specific local guidance with respect to the investigation and management of CLL. This consensus practice statement was developed by a broadly representative group of ANZ experts in CLL with endorsement by peak haematology bodies, with a view to providing this standardised guidance.

Immune Dysfunction and Infection - Interaction between CLL and Treatment: A Reflection on Current Treatment Paradigms and Unmet Needs

BACKGROUND

Chronic lymphocytic leukemia (CLL) is a hematological malignancy characterized by immune dysfunction, which significantly contributes to increased morbidity and mortality due to infections.

SUMMARY

Advancement in therapeutic strategies based on combination chemoimmunotherapy and targeted treatment have increased life expectancy for patients affected by CLL. However, mortality and morbidity due to infection showed no improvement over the last decades. Although therapy options are highly efficient in targeting leukemic cells, several studies highlighted the interactions of different treatments with the tumor microenvironment immune components, significantly impacting their clinical efficacy and fostering increased risk of infections.

KEY MESSAGES

Given the profound immune dysfunction caused by CLL itself, treatment can thus represent a double-edged sword. Thus, it is essential to increase our understanding and awareness on how conventional therapies affect the disease-microenvironment-infection axis to ensure the best personalized strategy for each patient. This requires careful consideration of the advantages and disadvantages of efficient treatments, whether chemoimmunotherapy or targeted combinations, leading to risk of infectious complications. To this regard, our machine learning-based algorithm CLL Treatment-Infection Model, currently implemented into the local electronic health record system for Eastern Denmark, aims at early identification of patients at high risk of serious infections (PreVent-ACaLL; NCT03868722). We here review strategies for management of immune dysfunction and infections in CLL.

Immunogenicity of the 13-Valent Pneumococcal Conjugated Vaccine Followed by the 23-Valent Polysaccharide Vaccine in Chronic Lymphocytic Leukemia

Patients with Chronic Lymphocytic Leukemia (CLL) have a 29- to 36-fold increased risk of invasive pneumococcal disease (IPD) compared to healthy adults. Therefore, most guidelines recommend vaccination with the 13-valent pneumococcal conjugated vaccine (PCV13) followed 2 months later by the 23-valent polysaccharide vaccine (PPSV23). Because both CLL as well as immunosuppressive treatment have been identified as major determinants of immunogenicity, we aimed to assess the vaccination schedule in untreated and treated CLL patients. We quantified pneumococcal IgG concentrations against five serotypes shared across both vaccines, and against four serotypes unique to PPSV23, before and eight weeks after vaccination. In this retrospective cohort study, we included 143 CLL patients, either treated (n = 38) or naive to treatment (n = 105). While antibody concentrations increased significantly after vaccination, the overall serologic response was low (10.5%), defined as a ≥4-fold antibody increase against ≥70% of the measured serotypes, and significantly influenced by treatment status and prior lymphocyte number. The serologic protection rate, defined as an antibody concentration of ≥1.3 µg/mL for ≥70% of serotypes, was 13% in untreated and 3% in treated CLL patients. Future research should focus on vaccine regimens with a higher immunogenic potential, such as multi-dose schedules with higher-valent T cell dependent conjugated vaccines.

Exposure of progressive immune dysfunction by SARS-CoV-2 mRNA vaccination in patients with chronic lymphocytic leukemia: A prospective cohort study

BACKGROUND

Patients with chronic lymphocytic leukemia (CLL) have reduced seroconversion rates and lower binding antibody (Ab) and neutralizing antibody (NAb) titers than healthy individuals following Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mRNA vaccination. Here, we dissected vaccine-mediated humoral and cellular responses to understand the mechanisms underlying CLL-induced immune dysfunction.

METHODS AND FINDINGS

We performed a prospective observational study in SARS-CoV-2 infection-naïve CLL patients (n = 95) and healthy controls (n = 30) who were vaccinated between December 2020 and June 2021. Sixty-one CLL patients and 27 healthy controls received 2 doses of the Pfizer-BioNTech BNT162b2 vaccine, while 34 CLL patients and 3 healthy controls received 2 doses of the Moderna mRNA-1273 vaccine. The median time to analysis was 38 days (IQR, 27 to 83) for CLL patients and 36 days (IQR, 28 to 57) for healthy controls. Testing plasma samples for SARS-CoV-2 anti-spike and receptor-binding domain Abs by enzyme-linked immunosorbent assay (ELISA), we found that all healthy controls seroconverted to both antigens, while CLL patients had lower response rates (68% and 54%) as well as lower median titers (23-fold and 30-fold; both p < 0.001). Similarly, NAb responses against the then prevalent D614G and Delta SARS-CoV-2 variants were detected in 97% and 93% of controls, respectively, but in only 42% and 38% of CLL patients, who also exhibited >23-fold and >17-fold lower median NAb titers (both p < 0.001). Interestingly, 26% of CLL patients failed to develop NAbs but had high-titer binding Abs that preferentially reacted with the S2 subunit of the SARS-CoV-2 spike. Since these patients were also seropositive for endemic human coronaviruses (HCoVs), these responses likely reflect cross-reactive HCoV Abs rather than vaccine-induced de novo responses. CLL disease status, advanced Rai stage (III-IV), elevated serum beta-2 microglobulin levels (β2m >2.4 mg/L), prior therapy, anti-CD20 immunotherapy (<12 months), and intravenous immunoglobulin (IVIg) prophylaxis were all predictive of an inability to mount SARS-CoV-2 NAbs (all p ≤ 0.03). T cell response rates determined for a subset of participants were 2.8-fold lower for CLL patients compared to healthy controls (0.05, 95% CI 0.01 to 0.27, p < 0.001), with reduced intracellular IFNγ staining (p = 0.03) and effector polyfunctionality (p < 0.001) observed in CD4+ but not in CD8+ T cells. Surprisingly, in treatment-naïve CLL patients, BNT162b2 vaccination was identified as an independent negative risk factor for NAb generation (5.8, 95% CI 1.6 to 27, p = 0.006). CLL patients who received mRNA-1273 had 12-fold higher (p < 0.001) NAb titers and 1.7-fold higher (6.5, 95% CI 1.3 to 32, p = 0.02) response rates than BNT162b2 vaccinees despite similar disease characteristics. The absence of detectable NAbs in CLL patients was associated with reduced naïve CD4+ T cells (p = 0.03) and increased CD8+ effector memory T cells (p = 0.006). Limitations of the study were that not all participants were subjected to the same immune analyses and that pre-vaccination samples were not available.

CONCLUSIONS

CLL pathogenesis is characterized by a progressive loss of adaptive immune functions, including in most treatment-naïve patients, with preexisting memory being preserved longer than the capacity to mount responses to new antigens. In addition, higher NAb titers and response rates identify mRNA-1273 as a superior vaccine for CLL patients.

Improved plasmablast response after repeated pneumococcal revaccinations following primary immunization with 13-valent pneumococcal conjugate vaccine or 23-valent pneumococcal polysaccharide vaccine in patients with chronic lymphocytic leukemia

BACKGROUND

Patients with chronic lymphocytic leukemia (CLL) show an immune dysfunction with increased risk of infections and poor response to vaccination. Streptococcus pneumoniae is a common cause of morbidity and mortality in CLL patients. In a previous randomized clinical trial, we found a superior immune response in CLL patients receiving conjugated pneumococcal vaccine compared to non-conjugated vaccine. The response to revaccination in CLL patients is scarcely studied. In this study, early humoral response to repeated revaccinations with pneumococcal vaccines was evaluated, by determination of B cell subsets and plasmablast dynamics in peripheral blood.

METHOD

CLL patients (n = 14) and immunocompetent controls (n = 31) were revaccinated with a 13-valent pneumococcal conjugate vaccine (PCV13) after previous primary immunization (3-6 years ago) with PCV13 or a 23-valent pneumococcal polysaccharide vaccine (PPSV23). Eight weeks after the first revaccination, all CLL patients received a second revaccination with PCV13 or PPSV23. B cell subsets including plasmablasts were analyzed in peripheral blood by flow cytometry, before and after the first and the second revaccination.

RESULTS

None of the CLL patients, but all controls, had detectable plasmablasts at baseline (p < 0.001). After the first revaccination with PCV13, the plasmablast proportions did not increase in CLL patients (p = 0.13), while increases were seen in controls (p < 0.001). However, after a second revaccination with PCV13 or PPSV23, plasmablasts increased compared to baseline also in CLL patients (p < 0.01). If no response was evident after first revaccination, only a second revaccination with PCV13 increased plasmablasts in contrast to PPSV23 revaccination. Patients with hypogammaglobulinemia and ongoing/previous CLL specific treatment responded poorly, also to a second revaccination.

CONCLUSION

In CLL patients, pneumococcal revaccination induced minor early plasmablast response compared to controls, but the response improved using a strategy of repeated doses with of conjugated T cell dependent pneumococcal vaccine.

SOHO State of the Art Updates and Next Questions | Infections in Chronic Lymphocytic Leukemia Patients: Risks and Management

Although chronic lymphocytic leukemia (CLL) is a malignancy characterized by accumulation of tumor cells in the blood, bone marrow, lymph nodes and secondary lymphoid tissues, the hallmark of the disease and the major cause of death for patients with CLL is actually immune dysfunction and associated infections. Despite improvement in treatment based on combination chemoimmunotherapy and targeted treatment with BTK and BCL-2 inhibitors leading to longer overall survival for patients with CLL, the mortality due to infections have not improved over the last 4 decades. Thus, infections are now the main cause of death for patients with CLL, posing threats to the patient whether during the premalignant state of monoclonal B lymphocytosis (MBL), during the watch & wait phase for treatment naïve patients, or upon treatment in terms of chemoimmunotherapy or targeted treatment. To test whether the natural history of immune dysfunction and infections in CLL can be changed, we have developed the machine learning based algorithm CLL-TIM.org to identify these patients. The CLL-TIM algorithm is currently being used for selection of patients for the clinical trial PreVent-ACaLL (NCT03868722), testing whether short-term treatment with the BTK inhibitor acalabrutinib and the BCL-2 inhibitor venetoclax can improve immune function and decrease the risk of infections for this high-risk patient population. We here review the background for and management of infectious risks in CLL.

Management of secondary immunodeficiency in hematological malignancies in the era of modern oncology

Secondary immunodeficiency (SID) in patients with B-cell hematological malignancies is a common condition that presents with recurrent infection. SID is due to both the inherent immune defects due to the malignancy, as well as secondary to cancer therapies, many of which have B-cell depleting properties. The early diagnosis of SID and the optimization of intervention strategies are key to delivering the most effective cancer treatments and reducing infection-related morbidity and mortality. This review discusses current practice, recommendations, and challenges for SID diagnosis, based on the evaluation of clinical history and laboratory assessments, and the effectiveness of specific vaccines and immunoglobulin replacement therapy in reducing the frequency and recurrence of infections in patients with SID, and the healthcare system-associated costs.

Immunoglobulin replacement in hematological malignancies: a focus on evidence, alternatives, dosing strategy, and cessation rule

Acquired hypogammaglobulinemia or secondary immunodeficiency (SID) occurs commonly in hematological malignancies with increasing incidence and complexity in the era of modern therapies. Despite current practice of immunoglobulin replacement (IgRT) in SID, the evidence is lacking, especially for newer treatments. We discuss the current evidence for IgRT in various disease groups including issues, such as actual or ideal body weight (IBW)-based dosing, length of treatment, antibiotic prophylaxis, and vaccination. Incidence of SID with newer treatment is lacking. While there is a trend toward decreased respiratory infections and hospitalizations with IgRT, this is not consistent across all disease course or treatment groups. Dosing and indications for cessation of IgRT are also inadequately characterized. Further randomized controlled trials (RCTs) and observational studies are required to assess the optimal indications, timing, and duration of IgRT to improve the efficacy, safety, and cost-effectiveness. Assessment of alternative and adjunctive therapies, such as vaccination and antibiotic prophylaxis could also improve the outcomes and costs.

Vaccination efficacy in patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a disorder of mature malignant B cells with multiple elements of immune dysfunction. Infections are common in CLL patients due to complex immunodeficiency. Vaccines are used as preventative measures for common diseases including influenza, pneumococcus, tetanus/diphtheria and shingles in the general population. Vaccines are utilized to mitigate this risk, although there have been some concerns regarding the efficacy of vaccines in the CLL population due to the inherent complex immune dysfunction associated with the disease. In this review, we describe the clinical and laboratory indicators for efficacy of the vaccines in the CLL population (including COVID-19, influenza, pneumonia, herpes zoster, and tetanus) and discuss immunization recommendations for patients with CLL.

SARS-CoV-2 mRNA vaccination exposes progressive adaptive immune dysfunction in patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) patients have lower seroconversion rates and antibody titers following SARS-CoV-2 vaccination, but the reasons for this diminished response are poorly understood. Here, we studied humoral and cellular responses in 95 CLL patients and 30 healthy controls after two BNT162b2 or mRNA-2173 mRNA immunizations. We found that 42% of CLL vaccinees developed SARS-CoV-2-specific binding and neutralizing antibodies (NAbs), while 32% had no response. Interestingly, 26% were seropositive, but had no detectable NAbs, suggesting the maintenance of pre-existing endemic human coronavirus-specific antibodies that cross-react with the S2 domain of the SARS-CoV-2 spike. These individuals had more advanced disease. In treatment-naïve CLL patients, mRNA-2173 induced 12-fold higher NAb titers and 1.7-fold higher response rates than BNT162b2. These data reveal a graded loss of immune function, with pre-existing memory being preserved longer than the capacity to respond to new antigens, and identify mRNA-2173 as a superior vaccine for CLL patients.

Anti-PD-L1/PD-L2 therapeutic vaccination in untreated chronic lymphocytic leukemia patients with unmutated IgHV

Chronic lymphocytic leukemia (CLL) patients with unmutated immunoglobulin heavy chain (IgHV) are at risk of early disease progression compared to patients with mutated IgHV. As a preventive strategy, we treated 19 previously untreated CLL patients with unmutated IgHV in a phase 1/2 trial (clinicaltrials.gov, NCT03939234) exploring the efficacy and toxicity of a therapeutic cancer vaccine containing peptides derived from programmed death ligand 1 (PD-L1) and ligand 2 (PD-L2), hoping to restore immunological control of the disease. According to the International Workshop on Chronic lymphocytic Leukemia (iwCLL) response criteria, no patients obtained a response; however, during follow-up, one patient had complete normalization of the peripheral lymphocyte count and remained in biochemical remission after a follow-up time of 15 months. At the end of treatment, one patient had progressed, and 17 patients had stable disease. During follow-up with a median time of 23.5 months since inclusion, seven patients had progressed, and eight patients had stable disease. The median time to first treatment (TTFT) from diagnosis was 90.3 months with a median follow-up time of 50.1 months. This apparent favorable outcome in TTFT needs to be investigated in a randomized setting, as our population may have been biased. More than 80% of patients obtained vaccine-specific immune responses, confirming the immunogenicity of the vaccine. The vaccine was generally well tolerated with only grade I–II adverse events. Although there were some signs of clinical effects, the vaccine seems to be insufficient as monotherapy in CLL, possibly due to a high tumor burden. The efficacy of the vaccine should preferably be tested in combination with novel targeted therapies or as a consolidating treatment.

Effectiveness, immunogenicity, and safety of COVID-19 vaccines for individuals with hematological malignancies: a systematic review

The efficacy of SARS-CoV-2 vaccination in patients with hematological malignancies (HM) appears limited due to disease and treatment-associated immune impairment. We conducted a systematic review of prospective studies published from 10/12/2021 onwards in medical databases to assess clinical efficacy parameters, humoral and cellular immunogenicity and adverse events (AE) following two doses of COVID-19 approved vaccines. In 57 eligible studies reporting 7393 patients, clinical outcomes were rarely reported and rates of SARS-CoV-2 infection (range 0–11.9%), symptomatic disease (0–2.7%), hospital admission (0–2.8%), or death (0–0.5%) were low. Seroconversion rates ranged from 38.1–99.1% across studies with the highest response rate in myeloproliferative diseases and the lowest in patients with chronic lymphocytic leukemia. Patients with B-cell depleting treatment had lower seroconversion rates as compared to other targeted treatments or chemotherapy. The vaccine-induced T-cell response was rarely and heterogeneously reported (26.5–85.9%). Similarly, AEs were rarely reported (0–50.9% ≥1 AE, 0–7.5% ≥1 serious AE). In conclusion, HM patients present impaired humoral and cellular immune response to COVID-19 vaccination with disease and treatment specific response patterns. In light of the ongoing pandemic with the easing of mitigation strategies, new approaches to avert severe infection are urgently needed for this vulnerable patient population that responds poorly to current COVID-19 vaccine regimens.

Safety and immunogenicity of the BNT162b2 mRNA Covid-19 vaccine in patients with chronic lymphocytic leukemia: a prospective study

Introduction:

Immunization of patients with chronic lymphocytic leukemia (CLL) with vaccines against several infectious diseases has proven insufficient. Data on seroconversion of patients with CLL after vaccination against severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) are still young, but accumulating evidence shows low seroconversion rates.

Methods:

We conducted a prospective, noninterventional study evaluating the safety and immunogenicity of two doses of the BNT162b2 mRNA Covid-19 vaccine, administered 21 days apart in consecutive adult patients with CLL. Patients vaccinated with other vaccines against SARS-CoV-2, with a history of confirmed Coronavirus Disease 19 (COVID-19), with known human immunodeficiency virus infection, or with an inability to provide written informed consent were excluded. Sera were tested before the first and after the second dose of the vaccine for anti-SARS-CoV-2 receptor binding domain (RBD) spike protein IgG (anti-RBD), using the Abbott SARS-CoV-2 IgG II Quant assay (Abbott Laboratories, Abbott Park, IL, USA), with a cutoff value for seroconversion at 50 AU/ml.

Results:

Sixty-one patients (28 males/33 females) with CLL, with a median age of 61 years, were included in the study. The majority of the patients (82.0%) were lower (0–2) stage per the RAI staging system. The seroconversion rate at 14 days after the second dose was 45% and was correlated with RAI stage (0–2 versus 3–4; 51.0% versus 18.3%, p = 0.047), the treatment status (treatment naïve, previously treated, or actively treated patients; 63.0% versus 40.0% versus 26.1%, respectively, p = 0.031), the number of previous treatment lines (0–2 versus >2; 55.3% versus 8.3%, p = 0.004), and the platelet count of the patients (over or under 100 × 109/L; 52.9% versus 10.0%, p = 0.015). Moreover, there was a positive linear relationship between the antibody titers and the gamma-globulin levels ( r = 0.182, p = 0.046) and platelet count ( r = 0.277, p = 0.002). Finally, patients actively treated with venetoclax had higher antibody titers than those treated with ibrutinib (15.8 AU/ml versus 0.0 AU/ml, p = 0.047). No safety issues were identified while the emergence of adverse events was not correlated with immunogenicity.

Discussion:

This study confirms results from previous studies on the low seroconversion rates in patients with CLL vaccinated with the BNT162b2 mRNA Covid-19 vaccine and on the detrimental effect of advanced disease and multiple treatment lines on seroconversion, while it is suggested that treatment with venetoclax may offer a chance for higher antibody titers, suggesting a treatment strategy change during the pandemic provided that this result is confirmed by larger studies specifically designed to address this issue.

Cellular Immune Response after Vaccination in Patients with Cancer—Review on Past and Present Experiences

Patients with cancer are at particular risk for infection but also have diminished vaccine responses, usually quantified by the level of specific antibodies. Nonetheless, vaccines are specifically recommended in this vulnerable patient group. Here, we discuss the cellular part of the vaccine response in patients with cancer. We summarize the experience with vaccines prior to and during the SARS-CoV-2 pandemic in different subgroups, and we discuss why, especially in patients with cancer, T cells may be the more reliable correlate of protection. Finally, we provide a brief outlook on options to improve the cellular response to vaccines.

Humoral and cellular immunogenicity of SARS-CoV-2 vaccines in chronic lymphocytic leukemia: a prospective cohort study

Chronic lymphocytic leukemia (CLL), the most common leukemia worldwide, is associated with increased COVID-19 mortality. Previous studies suggest only a proportion of vaccinated CLL patients develop SARS-CoV-2 spike antibodies. Whether the elicited antibodies are functional and/or accompanied by functional T-cell responses is unknown. This prospective cohort study (NCT05007860) included patients with CLL who received SARS-CoV-2 and PCV13 vaccines (not concurrently). The primary cohort included adults with CLL off therapy. Co-primary outcomes were serologic response to SARS-CoV-2 (receptor binding domain [RBD]-immunoassay) and PCV13 vaccines (23-serotype IgG assay). Characterization of SARS-CoV-2 antibodies and their functional activity and assessment of functional T-cell responses were performed. Sixty percent (18/30) of patients demonstrated serologic responses to SARS-CoV-2 vaccination, appearing more frequent among treatment-naïve patients (72%). Among treatment-naïve patients, an absolute lymphocyte count ≤24,000/uL was associated with serologic response (94% vs 14%, p&lt;0.001). On interferon gamma release assays, 80% (16/20) of patients had functional spike-specific T-cell responses, including 78% (7/9) with a negative RBD-immunoassay, a group enriched for prior B-cell depleting therapies. A bead-based multiplex immunoassay identified antibodies against wildtype and variant SARS-CoV-2 (alpha, beta, gamma, and delta) in all tested patients, and confirmed Fc-receptor binding and effector functions of these antibodies. Of 11 patients with negative RBD-immunoassay post-vaccination, 6 (55%) responded to an additional mRNA-based vaccine dose. The PCV13 serologic response rate was 29% (8/28). Our data demonstrate that SARS-CoV-2 vaccination induces functional T-cell and antibody responses in CLL patients and provides the framework for investigating the molecular mechanisms and clinical benefit of these responses. This trial is registered at www.clinicaltrials.gov as NCT05007860.

State of the CAR-T: Risk of Infections with Chimeric Antigen Receptor T-Cell Therapy and Determinants of SARS-CoV-2 Vaccine Responses

Chimeric antigen receptor T cell (CAR-T) therapy has shown unprecedented response rates in patients with relapsed/refractory (R/R) hematologic malignancies. Although CAR-T therapy gives hope to heavily pretreated patients, the rapid commercialization and cumulative immunosuppression of this therapy predispose patients to infections for a prolonged period. CAR-T therapy poses distinctive short- and long-term toxicities and infection risks among patients who receive CAR T-cells after multiple prior treatments, often including hematopoietic cell transplantation. The acute toxicities include cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. The long-term B cell depletion, hypogammaglobulinemia, and cytopenia further predispose patients to severe infections and abrogate the remission success achieved by the living drug. These on-target-off-tumor toxicities deplete B-cells across the entire lineage and further diminish immune responses to vaccines. Early observational data suggest that patients with hematologic malignancies may not mount adequate humoral and cellular responses to SARS-CoV-2 vaccines. In this review, we summarize the immune compromising factors indigenous to CAR-T recipients. We discuss the immunogenic potential of different SARS-CoV-2 vaccines for CAR-T recipients based on the differences in vaccine manufacturing platforms. Given the lack of data related to the safety and efficacy of SARS-CoV-2 vaccines in this distinctively immunosuppressed cohort, we summarize the infection risks associated with Food and Drug Administration-approved CAR-T constructs and the potential determinants of vaccine responses. The review further highlights the potential need for booster vaccine dosing and the promise for heterologous prime-boosting and other novel vaccine strategies in CAR-T recipients. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Poor neutralizing antibody responses in 106 patients with WM after vaccination against SARS-CoV-2: a prospective study

Anti–SARS-CoV-2 vaccination leads to lower production of antibodies in WM patients.

Treatment with rituximab or BTK inhibitors was an independent prognostic factor for suboptimal antibody response after vaccination.

Immunocompromised patients with hematologic malignancies are more susceptible to COVID-19 and at higher risk of severe complications and worse outcomes compared with the 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 Waldenström macroglobulinemia (WM) after vaccination with the BNT162b2 or AZD1222 vaccine. A US Food and Drug Administration–approved enzyme-linked immunosorbent assay–based methodology was implemented to evaluate NAbs on the day of the first vaccine shot, as well as on days 22 and 50 afterward. A total of 106 patients with WM (43% men; median age, 73 years) and 212 healthy controls (46% men; 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 on days 22 and 50 (P < .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 after vaccination. In conclusion, patients with WM have low humoral response after COVID-19 vaccination, which underlines the need for timely vaccination ideally during a treatment-free period and for continuous vigilance on infection control measures.

Reasons and consequences of COVID-19 vaccine failure in patients with chronic lymphocytic leukemia

People with hematologic malignancies are at a high risk of morbidity and mortality from COVID-19. The response to vaccination is highly limited in patients with chronic lymphocytic leukemia. Less than half of the patients develop antibody response, suggesting that they remain at risk of SARS-CoV-2 infection even after the vaccination. Reasons for inadequate response to COVID-19 vaccination in chronic lymphocytic leukemia are multifactorial and attributed to disease-related immune dysregulation and patient- and therapy-related factors. The negative predictors of response to vaccination include hypogammaglobulinemia, advanced age, current active treatment, and past treatment anti-CD20 monoclonal antibodies. Despite using booster doses and heterologous immunization to improve humoral and cellular immunity, some patients with chronic lymphocytic leukemia will fail to respond. Active treatment at the time of vaccination and a recent history of anti-CD20 monoclonal antibodies use are the strongest predictors of the non-response. Current data support informing patients with chronic lymphocytic leukemia and other hematologic malignancies about the risk of infection regardless of vaccination. These individuals and members of their households should continue extreme preventive actions despite relaxed local regulations. Other emerging non-vaccine preventive strategies include passive and post-exposure prevention with monoclonal antibodies.

Subcutaneous immunoglobulin replacement for treatment of humoral immune dysfunction in patients with chronic lymphocytic leukemia

Background

Patients with chronic lymphocytic leukemia (CLL) experience hypogammaglobinemia and non-neutropenic infections. In this exploratory proof of concept study, our objective was to determine the prevalence of humoral immunodeficiency in patients with CLL and serum IgG ≥ 400 mg/dL, and to evaluate the efficacy of subcutaneous immunoglobulin (SCIG) in this population.

Patients and methods

Patients with CLL with serum IgG ≥ 400 mg/dL were evaluated for serum IgG, IgM, IgA, along with pre/post vaccine IgG titers to diphtheria, tetanus, and Streptococcus pneumoniae. Patients with evidence of humoral dysfunction were treated with SCIG with Hizentra every 7±2 days for 24 weeks.

Results

Fifteen patients enrolled with median IgG = 782 mg/dL [IQR: 570 to 827], and 6/15 (40%) responded to vaccination with Td, while 5/15 (33%) responded to vaccination with PPV23. 14/15 (93.3%) demonstrated humoral immunodeficiency as evidenced by suboptimal vaccine responses, and were treated with SCIG. In patients treated with SCIG, serum IgG increased from 670 mg/dL [IQR: 565 to 819] to 1054 mg/dL [IQR: 1040 to 1166] after 24 weeks (95% CI: 271–540). For streptococcus pneumoniae, the median protective serotypes at baseline was 8 [IQR: 4 to 9] and increased to 17 [IQR: 17 to 19] after 24 weeks (95% CI: 6.93–13.72). Non-neutropenic infections (NNI) decreased from 14 to 5 during treatment with SCIG.

Conclusions

Patients with CLL demonstrate humoral immunodeficiency despite IgG > 400 mg/dL. For these patients, SCIG is well tolerated and efficacious in improving serum IgG, specific IgG to streptococcus pneumoniae, and may decrease reliance on antibiotics for the treatment of NNIs.

Clinical trials registration

NCT 03730129.

[Vaccines against COVID-19]

Die anhaltende COVID-19-Pandemie stellt eine Notlage verheerenden Ausmaßes dar. Um ihr entgegenzuwirken, wurden in kürzester Zeit mehrere sichere und wirksame Impfstoffe entwickelt. Aktuell sind 4 Impfstoffe durch die Europäische Arzneimittel-Agentur (EMA) zugelassen und werden in Deutschland verwendet. Hierzu zählen 2 mRNA-Impfstoffe und 2 vektorbasierte Impfstoffe. Alle zeigen eine sehr gute Schutzwirkung, insbesondere vor schweren Krankheitsverläufen, und können die Pandemie durch die Reduktion der Virustransmission maßgeblich eindämmen. Im Fokus des vorliegenden Beitrags stehen der Entwicklungsprozess und Wirkmechanismus der Impfstoffe, ihr Sicherheits- und Wirkungsprofil sowie Impfindikationen und aktuelle Empfehlungen zur Anwendung der Impfstoffe bei besonderen Personengruppen wie rekonvaleszenten und immunsupprimierten Patient:innen sowie Schwangeren. Aktuell offene Fragen werden aus wissenschaftlicher Sicht thematisiert.

Poor Neutralizing Antibody Responses in 132 Patients with CLL, NHL and HL after Vaccination against SARS-CoV-2: A Prospective Study

Emerging data suggest suboptimal antibody responses to COVID-19 vaccination in patients with hematological malignancies. We evaluated the humoral response following the BNT162b2 vaccine in patients with chronic lymphocytic leukemia (CLL), non-Hodgkin's lymphoma (NHL), and Hodgkin's lymphoma (HL). An FDA-approved, ELISA-based methodology was implemented to evaluate the titers of neutralizing antibodies (NAbs) against SARS-CoV-2 on day 1 of the first vaccine, and afterwards on day 22 and 50. One hundred and thirty-two patients with CLL/lymphomas and 214 healthy matched controls vaccinated during the same period, at the same center were enrolled in the study (NCT04743388). Vaccination with two doses of the BNT162b2 vaccine led to lower production of NAbs against SARS-CoV-2 in patients with CLL/lymphomas 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 Rituximab, Bruton's tyrosine kinase inhibitors, or chemotherapy was an independent prognostic factor for suboptimal antibody response. Patients with HL showed superior humoral responses to the NHL/CLL subgroups. In conclusion, patients with CLL/lymphomas have low humoral response following COVID-19 vaccination, underlining the need for timely vaccination ideally during a treatment-free period and for continuous vigilance on infection control measures.

COVID-19 and Chronic Lymphocytic Leukemia: Where We Stand Now

ABSTRACT

Coronavirus disease 2019 (COVID-19) has markedly impacted on the management of patients with chronic lymphocytic leukemia (CLL) and their outcome in the last year. The cumulative incidence of COVID-19 in patients with CLL in 1 year was approximately 3% in the recent Italian CAMPUS CLL survey; large retrospective studies have documented a higher mortality in patients with CLL hospitalized for severe COVID-19 compared with the general population. Controversial results for CLL-directed treatment have been reported, with some studies suggesting a potential benefit for BTK inhibitors. Reducing the number of hospital visits, delaying treatment whenever possible, and using oral therapy have become the mainstay of management in these patients. Available results with severe acute respiratory syndrome coronavirus 2 vaccines indicate an immune serological response in 40% of patients only, with a detrimental effect of recent therapy with or without anti-CD20 therapy, older age, and hypogammaglobulinemia. Further studies are needed to determine the best strategies in patients with CLL regarding (i) management of concomitant COVID-19, (ii) identification of patients in whom CLL therapy can be safely postponed, (iii) CLL treatment algorithms, and (iv) optimal severe acute respiratory syndrome coronavirus 2 vaccination strategies.

Serological SARS-CoV-2 antibody response, potential predictive markers and safety of BNT162b2 mRNA COVID-19 vaccine in haematological and oncological patients

Haemato‐oncological patients are at risk in case of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection. Currently, vaccination is the best‐evaluated preventive strategy. In the present study, we aimed to assess serological response, predictive markers, and safety of BNT162b2 in haemato‐oncological patients. A total of 259 haemato‐oncological patients were vaccinated with two 30 µg doses of BNT162b2 administered 21 days apart. Serological response was assessed by ELECSYS^® Anti‐SARS‐CoV‐2‐S immunoassay before vaccination, and at 3 and 7 weeks after the first dose (T1, T2). Safety assessment was performed. At T2 spike protein receptor binding domain (S/RBD) antibodies were detected in 71·4% of haematological and in 94·5% of oncological patients (P < 0·001). Haematological patients receiving systemic treatment had a 14·2‐fold increased risk of non‐responding (95% confidence interval 3·2–63·3, P = 0·001). Subgroups of patients with lymphoma or chronic lymphocytic leukaemia were at highest risk of serological non‐response. Low immunoglobulin G (IgG) level, lymphocyte‐ and natural killer (NK)‐cell counts were significantly associated with poor serological response (P < 0·05). Vaccination was well tolerated with only 2·7% of patients reporting severe side‐effects. Patients with side‐effects developed a higher S/RBD‐antibody titre compared to patients without side‐effects (P = 0·038). Haematological patients under treatment were at highest risk of serological non‐response. Low lymphocytes, NK cells and IgG levels were found to be associated with serological non‐response. Serological response in oncological patients was encouraging. The use of BNT162b2 is safe in haemato‐oncological patients.

BTK Inhibitors in Chronic Lymphocytic Leukemia: Biological Activity and Immune Effects

Bruton´s tyrosine kinase (BTK) inhibitor (BTKi)s block the B-cell receptor (BCR) signaling cascade by binding to the BTK enzyme preventing the proliferation and survival of malignant and normal B cells. During the past decade, the clinical use of BTKis for the treatment of B-cell malignancies has exponentially grown, changing the treatment landscape for chronic lymphocytic leukemia (CLL) in particular. At present, three different covalent BTKis, ibrutinib, acalabrutinib and zanubrutinib, are FDA-approved and many new inhibitors are under development. Despite having remarkable selectivity for BTK, the first-in-class BTKi ibrutinib can also bind, with various affinities, to other kinases. The combined inhibition of BTK (“on-target” effect) and other kinases (“off-target” effect) can have additive or synergistic anti-tumor effects but also induce undesired side effects which might be treatment-limiting. Such “off-target” effects are expected to be more limited for second-generation BTKis. Moreover, the blockade of BCR signaling also indirectly affects the tumor microenvironment in CLL. Treatment with BTKis potentially impacts on both innate and adaptive immunity. Whether this affects infection susceptibility and vaccination efficacy requires further investigation. Here, we summarize the available knowledge on the impact of BTKis on the immune system and discuss the possible clinical implications. Indeed, a deeper knowledge on this topic could guide clinicians in the management and prevention of infections in patients with CLL treated with BTKis.

Efficacy of the BNT162b2 mRNA COVID-19 vaccine in patients with chronic lymphocytic leukemia

Patients with chronic lymphocytic leukemia (CLL) have an increased risk for severe COVID-19 disease and mortality. The goal of this study was to determine the efficacy of COVID-19 vaccine in patients with CLL. We evaluated humoral immune responses to the BNT162b2 messenger RNA (mRNA) COVID-19 vaccine in patients with CLL and compared responses with those obtained in age-matched healthy control subjects. Patients received 2 vaccine doses, 21 days apart, and antibody titers were measured by using the Elecsys Anti-SARS-CoV-2 S assay after administration of the second dose. In a total of 167 patients with CLL, the antibody response rate was 39.5%. A comparison between 52 patients with CLL and 52 sex- and aged-matched healthy control subjects revealed a significantly reduced response rate among patients (52% vs 100%, respectively; adjusted odds ratio, 0.010; 95% confidence interval, 0.001-0.162; P < .001). The response rate was highest in patients who obtained clinical remission after treatment (79.2%), followed by 55.2% in treatment-naive patients and 16.0% in patients under treatment at the time of vaccination. In patients treated with either Bruton's tyrosine kinase inhibitors or venetoclax ± anti-CD20 antibody, response rates were considerably low (16.0% and 13.6%). None of the patients exposed to anti-CD20 antibodies <12 months before vaccination responded. In a multivariate analysis, the independent predictors of response were younger age, female sex, lack of currently active treatment, immunoglobulin G levels ≥550 mg/dL, and immunoglobulin M levels ≥40 mg/dL. In conclusion, antibody-mediated response to the BNT162b2 mRNA COVID-19 vaccine in patients with CLL is markedly impaired and affected by disease activity and treatment. This trial was registered at www.clinicaltrials.gov as #NCT04746092.

Can Immunocompetence Be Restored in Chronic Lymphocytic Leukemia?

Reversing or preventing immunodeficiency in patients with chronic lymphocytic leukemia (CLL) is of the highest priority. The past decade of research has met the challenge of treating CLL for most patients. Patients continue to struggle, however, with infections and second primary malignancies related to immunodeficiency. Strategies addressing this need currently are limited to vaccinations, with suboptimal efficacy, and immunoglobulin replacement. Correlative studies have provided insights into immunologic alterations on treatment. Understanding vulnerabilities in the immune system may help identify potential interventions to boost immunity. An emphasis on systematically testing such interventions is required to restore immunocompetence in patients with CLL.

Safety of vaccines used for routine immunization in the United States: An updated systematic review and meta-analysis

BACKGROUND

Understanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines recommended for children, adults, and pregnant women in the United States.

METHODS

We searched the literature in November 2020 to update a 2014 Agency for Healthcare Research and Quality review by integrating newly available data. Studies of vaccines that used a comparator and reported the presence or absence of key adverse events were eligible. Adhering to Evidence-based Practice Center methodology, we assessed the strength of evidence (SoE) for all evidence statements. The systematic review is registered in PROSPERO (CRD42020180089).

RESULTS

Of 56,603 reviewed citations, 338 studies reported in 518 publications met inclusion criteria. For children, SoE was high for no increased risk of autism following measles, mumps, and rubella (MMR) vaccine. SoE was high for increased risk of febrile seizures with MMR. There was no evidence of increased risk of  intussusception with rotavirus vaccine at the latest follow-up (moderate SoE), nor of diabetes (high SoE). There was no evidence of increased risk or insufficient evidence for key adverse events for newer vaccines such as 9-valent human papillomavirus and meningococcal B vaccines. For adults, there was no evidence of increased risk (varied SoE) or insufficient evidence for key adverse events for the new adjuvanted inactivated influenza vaccine and recombinant adjuvanted zoster vaccine. We found no evidence of increased risk (varied SoE) for key adverse events among pregnant women following tetanus, diphtheria, and acellular pertussis vaccine, including stillbirth (moderate SoE).

CONCLUSIONS

Across a large body of research we found few associations of vaccines and serious key adverse events; however, rare events are challenging to study. Any adverse events should be weighed against the protective benefits that vaccines provide.

Effect of Bruton tyrosine kinase inhibitor on efficacy of adjuvanted recombinant hepatitis B and zoster vaccines

Vaccinations are effective in preventing infections; however, it is unknown if patients with chronic lymphocytic leukemia (CLL) who are treatment naïve (TN) or receiving Bruton tyrosine kinase inhibitors (BTKi's) respond to novel adjuvanted vaccines. Understanding the effect of BTKi's on humoral immunity is timely because BTKi's are widely used and vaccination against coronavirus disease 2019 is urgently needed. In 2 open-label, single-arm clinical trials, we measured the effect of BTKi's on de novo immune response against recombinant hepatitis B vaccine (HepB-CpG) and recall response against recombinant zoster vaccine (RZV) in CLL patients who were TN or on BTKi. The primary end point was serologic response to HepB-CpG (anti-hepatitis B surface antibodies ≥10 mIU/mL) and RZV (≥fourfold increase in anti-glycoprotein E). The response rate to HepB-CpG was lower in patients on BTKi (3.8%; 95% confidence interval [CI], 0.7-18.9) than patients who were TN (28.1%; 95% CI, 15.6-45.4; P = .017). In contrast, the response rate to RZV did not differ significantly between the BTKi (41.5%; 95% CI, 27.8-56.6) and TN cohorts (59.1%; 95% CI, 38.7-76.7; P = .2). BTKi's were associated with a decreased de novo immune response following HepB-CpG, whereas recall immune response following RZV was not significantly affected by BTKi therapy. These trials were registered at www.clinicaltrials.gov as #NCT03685708 (Hep-CpG) and #NCT03702231 (RZV).

Casting a wider protective net: Anti-infective vaccine strategies for patients with hematologic malignancy and blood and marrow transplantation

Patients who have hematologic malignancies are at high risk for infections but vaccinations may be effective prophylaxis. The increased infection risk derives from immune defects secondary to malignancy, the classic example being CLL, and chemotherapies and immunotherapy used to treat the malignancies. Therapy of hematologic malignancies is being revolutionized by introduction of novel targeted agents and immunomodulatory medications, improving the survival of patients. At the same time those agents uniquely change the infection risk and response to immunizations. This review will summarize current vaccine recommendations for patients with hematologic malignancies including patients who undergo hematopoietic cell transplant.

Secondary immunodeficiencies with predominant antibody deficiency: multidisciplinary perspectives of Polish experts

At present, secondary immune deficiencies have become a clinical problem, recognized in different specialties. The aim of this paper was to increase awareness and support the need for screening at-risk populations. Secondary immune deficiencies result in variety of conditions, but not all of them require immunoglobulin replacement therapy, as specific antibody response might be preserved. Moreover, the management of secondary immune deficiencies vary between countries and different medical disciplines. This literature review presents the most common causes and clinical presentation of secondary immunodeficiencies with predominant impaired antibody production. We present diagnostic guidelines for patients at-risk, with an emphasis on the role of prophylactic vaccination as a treatment and diagnostic tool. This review considers the specificity and disparities of the Polish healthcare system and ultimately, suggests that management teams should include a clinical immunologist experienced in the treatment of humoral immunodeficiencies.

Early Intervention with Lenalidomide in Patients with High-risk Chronic Lymphocytic Leukemia

PURPOSE

Infectious complications constitute a leading cause of morbidity and mortality in chronic lymphocytic leukemia (CLL). Patients respond poorly to vaccines, particularly pneumococcal polysaccharide and influenza vaccines. In addition, patients with genetically high-risk disease are at increased risk for early disease progression and death. Lenalidomide, an oral immunomodulatory agent with demonstrated clinical activity in CLL, can potentially restore immune system dysfunction associated with CLL while improving disease outcomes.

PATIENTS AND METHODS

Phase II study randomized 49 patients with genetically high-risk CLL or small lymphocytic lymphoma [SLL; defined as unmutated Ig heavy chain variable region, deletion(17p) or (11q), and/or complex abnormal karyotype], to receive lenalidomide either concurrent (arm A) or sequential to (arm B) two doses of 13-valent protein-conjugated pneumococcal vaccine (PCV13) administered 2 months apart, in patients not meeting International Workshop on Chronic Lymphocytic Leukemia treatment criteria.

RESULTS

Four serotypes (3, 4, 5, 6B) achieved the additional seroprotection definition of a fourfold increase in arm A, and six serotypes (3, 4, 5, 6B, 19A, 19F) in arm B. All patients achieved the defined concentration of 0.35 μg/mL for at least one serotype tested. No significant difference was observed with the addition of lenalidomide. At median time on treatment of 3.6 years, median progression-free survival (PFS) was 5.8 years [95% confidence interval (CI), 3.1-not reached]. PFS at 1, 2, and 3 years was 85% (95% CI, 72-93), 79% (95% CI, 64-88), and 72% (95% CI, 57-83), respectively.

CONCLUSIONS

Lenalidomide is efficacious with manageable toxicities as an early intervention strategy in patients with high-risk CLL, but did not enhance humoral response to PCV13 vaccine.

Response to the conjugate pneumococcal vaccine (PCV13) in patients with chronic lymphocytic leukemia (CLL)

Pneumococcal (PC) vaccination is recommended for patients with chronic lymphocytic leukemia (CLL). However, response to vaccines has been investigated in a small series of CLL patients. We analyzed the antibody response and outcomes of 112 CLL patients who received the 13-valent pneumococcal conjugate vaccine (PCV13). An immune response was defined by a twofold increase in the PC-IgG levels assessed by ELISA. The median age of patients was 68 years, 23.2% showed IgG levels ≤ 400 mg/L, 6.3% progressive disease, 52% unmutated IGHV. Twenty-two (19.6%) patients were treatment-naïve and 90 (80.4%) previously treated (40.2% front-line chemoimmunotherapy; ibrutinib first/advanced-line, 9.8%/21.4%; idelalisib advanced-line, 8.9%). Nine (8%) patients developed an immune response, eight treatment-naive, and one on front-line ibrutinib. No responses were observed in patients previously treated with chemoimmunotherapy. Age ≥ 60 years (p = 0.007), IgG levels < 400 mg/L (p < 0.0001), prior treatment (p < 0.0001), and signs of disease progression (p = 0.04) were associated with a lower response rate. Pneumonia-free survival was significantly shorter in patients with clinical signs of progressive disease (HR, 8.39), prior pneumonia (HR, 7.03), and TP53 disruption (HR, 2.91). In conclusion, our results suggest that vaccination should be offered at diagnosis to CLL patients with early stage and stable disease who have better resources for an effective immune response.

Immunogenicity and safety of the 13-valent pneumococcal conjugate vaccine in patients with immunocompromising conditions: a review of available evidence

Immunocompromising conditions increase the risk of invasive pneumococcal disease (IPD). Vaccine uptake in patients with these conditions may be low in part because of concerns about decreased immunogenicity and safety in these high-risk groups. We conducted a literature search to identify publications describing antibody responses to 13-valent pneumococcal conjugate vaccine (PCV13) in immunocompromised individuals recommended for PCV13 vaccination by the US Advisory Committee on Immunization Practices (ACIP). This review summarizes immunogenicity data from 30 publications regarding the use of PCV13 comprising 2406 individuals considered at high risk for IPD by the ACIP. Although antibody responses to PCV13 in individuals with immunocompromising and high-risk conditions were variable and generally lower compared with healthy controls, the vaccine was immunogenic and was largely well tolerated. Based on these findings, concerns regarding immunogenicity and safety of PCV13 are not supported and should not be barriers to vaccination in high-risk populations.

Cost Effectiveness of Elderly Pneumococcal Vaccination in Presence of Higher-Valent Pneumococcal Conjugate Childhood Vaccination: Systematic Literature Review with Focus on Methods and Assumptions

BACKGROUND

Previous systematic reviews concluded that pneumococcal vaccination in the elderly was cost effective. However, recently published economic evaluations state that it may not be cost effective when children are vaccinated with higher-valent pneumococcal conjugate vaccines. The literature suggests that the outcomes of vaccination in the elderly are strongly influenced by the vaccine effectiveness (VE) against the vaccine-type pneumococcal diseases (PD) and the impact of childhood vaccination on the vaccine-type PD incidence in the elderly, but the extent remains unclear.

METHODS

We conducted a systematic literature search of cost-effectiveness studies on vaccination in the elderly in the PubMed database starting from 2006. We included studies that consider the presence of a childhood vaccination with pneumococcal conjugate vaccine (PCV) 10 and PCV13. We focus on methods and assumptions used in modeling VE and epidemiology of PD over time.

RESULTS

Twenty-eight economic evaluations underwent full-text review and data extraction. Thirteen were selected for quality assessment. The studies with a higher quality score provide evidence that vaccinating the elderly with PCV13 is not cost effective, when an ongoing rapid decline in the incidence of PCV13-type PD is modeled. A moderate persistence of PCV13 serotypes, in particular due to PCV10 childhood vaccination, makes vaccination of the elderly with PCV13 more attractive. There is no agreement that combining PCV13 with polysaccharide vaccine PPSV23 is cost effective. PPSV23 is attractive when it is effective against non-invasive PD.

CONCLUSION

Methodological approaches and assumptions in modeling VE and the indirect effects of childhood vaccination have a major impact on outcomes of decision-analytic models and cost-effectiveness estimates. Considering recently observed trends in the epidemiology of pneumococcal serotypes, there is currently inconclusive evidence regarding the cost effectiveness of pneumococcal vaccination of the elderly due to lack of studies that model key serotypes such as serotype 3 separately from other groups of serotypes.

Antibody response to the 23-valent pneumococcal polysaccharide vaccine after conjugate vaccine in patients with chronic lymphocytic leukemia

The 23-valent pneumococcal polysaccharide vaccine (PPV23) given alone is ineffective in patients with chronic lymphocytic leukemia (CLL) and better antibody response is achieved with pneumococcal conjugate vaccines (PCVs). In this study, we determine whether CLL patients would achieve a significant antibody response and broaden their serotype coverage against invasive pneumococcal disease (IPD) with PPV23 given five years after the 7-valent conjugate vaccine (PCV7). A total of 24 patients with CLL and eight controls were vaccinated with PPV23 five years after PCV7. Blood samples for evaluation of antibody response to PCV7 serotypes and PPV23 serotypes 5 and 7 were taken before vaccination and one month after it. Post-vaccination samples were available from 20 patients. IgG antibodies were measured with ELISA. Antibody concentrations after PPV23 were significantly lower in CLL patients for six of the PCV7 serotypes and for both PPV23 serotypes. Only 10% to 15% of CLL patients achieved an antibody response suggested to be protective against IPD. Hence, PCV7 given five years before PPV23 did not improve antibody response in patients with CLL. Based on our results, PPV23 given after a PCV primer is not useful against IPD in CLL patients.

Epidemiology of bloodstream infections in patients with chronic lymphocytic leukemia: a longitudinal nation-wide cohort study

Patients with chronic lymphocytic leukemia (CLL) have a high risk of bloodstream infections (BSI). BSI cause significant morbidity and mortality among CLL patients; approximately one-third of fatalities in CLL list infections as cause of death. All CLL patients in Denmark diagnosed between 2008 and 2016 were followed through registries for the event of a BSI. Patient characteristics and bacterial findings were analyzed separately for treatment-naive and treated patients. A total of 3677 and 1020 patients with CLL were followed as treatment-naive and treated patients, respectively. We identified 145 cases of Gram-positive bacteremia. Streptococcus pneumoniae accounted for 32 (22%) cases, while Staphylococcus aureus was found 30 times (21%). Gram-negative microorganisms were found in 166 (46%) cases. Escherichia coli accounted for 77 (46%) cases. Lastly, we identified six episodes of candidemia of which five (83%) were fatal within 30 days of the infection. Based on increased frequency of S. pneumoniae and Pseudomonas aeruginosa and the high mortality of candidemia in CLL, empirical antibiotics with double coverage for S. pneumoniae and P. aeruginosa is recommended; upon suspected or proven candidemia, treatment with broad-spectrum fungicidal agents are recommended.