Vaccination of haemopoietic stem cell transplant recipients: guidelines of the 2017 European Conference on Infections in Leukaemia (ECIL 7)

Adoptive transfer of donor B lymphocytes: a phase 1/2a study for patients after allogeneic stem cell transplantation

ABSTRACT

Immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is slow and patients carry a high and prolonged risk of opportunistic infections. We hypothesized that the adoptive transfer of donor B cells can foster after HSCT immuno-reconstitution. Here, we report, to our knowledge, the results of a first-in-human phase 1/2a study aimed to evaluate the feasibility and safety of adoptively transferred donor B cells and to test their activity upon recall vaccination. Good manufactoring practice (GMP) B-cell products were generated from donor apheresis products using 2-step magnetic cell separation. Fifteen patients who had undergone allo-HSCT were enrolled and treated after taper of immunosuppression (median, day +148; range, 130-160). Patients received 4 different doses of B cells (0.5 × 106 to 4.0 × 106 B cells per kg body weight). To test the activity of infused donor memory B cells in vivo, patients were vaccinated with a pentavalent vaccine 7 days after B-cell transfer. We observed the mobilization of plasmablasts and an increase in serum titers against vaccine antigens, with a stronger response in patients receiving higher B-cell numbers. Analysis of immunoglobulin VH-sequences by next-generation sequencing revealed that plasmablasts responding to vaccination originated from memory B-cell clones from the donor. Donor B-cell transfer was safe, as no Epstein-Barr virus (EBV) reactivation was observed, and only low-grade graft-versus-host disease (GVHD) occurred in 4 out of 15 patients. This pilot trial may pave the way for further studies exploring the adoptive transfer of memory B cells to reduce the frequency of infections after allo-HSCT. This trial was registered at ClinicalTrial.gov as #NCT02007811.

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.

Immunophenotypic predictors of influenza vaccine immunogenicity in pediatric hematopoietic cell transplant recipients

ABSTRACT

Pediatric hematopoietic cell transplant (HCT) recipients exhibit poor serologic responses to influenza vaccination early after transplant. To facilitate the optimization of influenza vaccination timing, we sought to identify B- and T-cell subpopulations associated with influenza vaccine immunogenicity in this population. We used mass cytometry to phenotype peripheral blood mononuclear cells collected from pediatric HCT recipients enrolled in a multicenter influenza vaccine trial comparing high- and standard-dose formulations over 3 influenza seasons (2016-2019). We fit linear regression models to estimate relationships between immune cell subpopulation numbers before vaccination and prevaccination to postvaccination geometric mean fold rises in antigen-specific (A/H3N2, A/H1N1, and B/Victoria) serum hemagglutination inhibition antibody titers (28-42 days, and ∼6 months after 2 doses). For cell subpopulations identified as predictive of a response to all 3 antigens, we conducted a sensitivity analysis including time after transplant as an additional covariate. Among 156 HCT recipients, we identified 33 distinct immune cell subpopulations; 7 significantly predicted responses to all 3 antigens 28 to 42 days after a 2-dose vaccine series, irrespective of vaccine dose. We also found evidence that baseline absolute numbers of naïve B cells, naïve CD4+ T cells, and circulating T follicular helper cells predicted peak and sustained vaccine-induced titers irrespective of dose or timing of posttransplant vaccine administration. In conclusion, several B- and T-cell subpopulations predicted influenza vaccine immunogenicity in pediatric HCT recipients. This study provides insights into the immune determinants of vaccine responses and may help guide the development of tailored vaccination strategies for this vulnerable population.

Monitoring Humoral Response Following BNT162b2 mRNA Vaccination against SARS-CoV-2 in Hematopoietic Stem-Cell Transplantation Patients: A Single-Center Prospective Study along with a Brief Review of Current Literature

Data on antibody response (AR) after vaccination against SARS-CoV2 in hematopoietic stem-cell transplantation setting (HSCT) were initially scarce, mainly due to the exclusion of such patients from approval studies. Shortly after the worldwide application of vaccination against SARS-CoV-2 in vulnerable populations such as patients with hematologic malignancies, limited single-center trials, including HSCT patients, were published. However, there was a great heterogeneity between them regarding the type of underlying malignancy, co-current treatment, type of vaccine, method of AR measurement, and time point of AR measurement. Herein, we present the results of a prospective study on AR after vaccination for SARS-CoV-2 using the BNT162b2 vaccine in a cohort of 54 HSCT recipients-mostly autologous from a single Unit-along with a broad review of the current literature. In our cohort, the AR positivity rate at 1 month was 80.8% and remained positive in 85.7% of patients at 3 months after vaccination. There were only nine non-responders, who were more heavily pretreated and more frequently hypogammaglobulinemic compared to responders. High antibody titers (AT), [AT ≥ 1000 U/mL], were detected in 38.5% and 30.6% of the patients at m1 and m3, respectively. A significant decline in AT between m1 and m3 was demonstrated-p < 0.0001; median AT1 and AT3 were 480.5 and 293 U/mL, respectively. A novel finding of our study was the negative impact of IgA hypogammaglobulinemia on response to vaccination. Other negative significant factors were treatment with anti-CD20 antibody at vaccination and vaccination within 18 months from HSCT. Our data indicate that HSCT recipients elicit a positive response to the BNT162b2 vaccine against SARS-CoV-2 when vaccinated at 6 months post-transplant, and vaccination should be offered to this patient population even within the post-pandemic COVID-19 era.

Invasive pneumococcal serotype 3 infection following pneumococcal vaccination in a hematopoietic stem cell transplant patient: A case report

Given the high mortality rate of invasive pneumococcal disease (IPD) in hematopoietic stem cell transplant (HSCT) recipients, vaccination is recommended. These recipients respond to most vaccines; however, their immune response is typically weaker during the first months or years after transplantation, compared with that of healthy individuals. Here, we report a case of IPD with serotype 3 pneumonia and empyema in an HSCT recipient who had received three doses of the 13-valent pneumococcal conjugate vaccine (PCV) and one dose of the 23-valent pneumococcal polysaccharide vaccine; furthermore, the recipient had no relapse, graft-versus-host disease, or use of immunosuppressive agents after allogeneic HSCT for acute myeloid leukemia. Moreover, we discussed the characteristics of serotype 3 Streptococcus pneumoniae, a case series of breakthrough infections with S. pneumoniae in HSCT recipients who received pneumococcal vaccines, and the potential implications for the upcoming PCV15 and PCV20 vaccines for serotype 3.

International Recommendations for Screening and Preventative Practices for Long-Term Survivors of Transplantation and Cellular Therapy: A 2023 Update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the number of HCTs performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pretransplantation, peritransplantation, and post-transplantation exposures and other underlying risk factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and then updated in 2012. An international group of experts was convened to review the contemporary literature and update the recommendations while considering the changing practices of HCT and cellular therapy. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed, but cGVHD management is not covered in detail. These guidelines emphasize the special needs of patients with distinct underlying HCT indications or comorbidities (eg, hemoglobinopathies, older adults) but do not replace more detailed group-, disease-, or condition-specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

Spike-Specific Memory B Cell Response in Hematopoietic Cell Transplantation Recipients following Multiple mRNA-1273 Vaccinations: A Longitudinal Observational Study

Preventing SARS-CoV-2 infection is of utmost importance in allogeneic hematopoietic cell transplantation patients (allo-HCT), given their heightened susceptibility to adverse outcomes associated with SARS-CoV-2 infection. However, limited data are available regarding the immune response to COVID-19 vaccines in these subjects, particularly concerning the generation and persistence of spike-specific memory response. Here, we analyzed the spike-specific memory B cells in a cohort of allo-HCT recipients vaccinated with multiple doses of the mRNA-1273 vaccine and monitored the spike-specific antibody response from baseline up to one month after the fourth dose. After the primary vaccine series, the frequency of spike-specific B cells, detected within the pool of Ig-switched CD19+ cells, significantly increased. The booster dose further induced a significant expansion, reaching up to 0.28% of spike-specific B cells. The kinetics of this expansion were slower in the allo-HCT recipients compared to healthy controls. Spike-specific IgG and ACE2/RBD binding inhibition activity were observed in 80% of the allo-HCT recipients after the first two doses, with a significant increase after the third and fourth booster doses, including in the subjects who did not respond to the primary vaccine series. Additionally, 87% of the allo-HCT recipients exhibited positive cross-inhibition activity against the BA.1 variant. Our findings provide evidence that allo-HCT recipients need repeated doses of the mRNA-1273 vaccine to induceSARS-CoV-2 specific immune response similar to that observed in healthy individuals. This is particularly crucial for vulnerable individuals who may exhibit a limited response to the primary series of SARS-CoV-2 vaccination.

Facilitators and Barriers to Successful Revaccination after Hematopoietic Stem Cell Transplantation among Adult Survivors: A Scoping Review

Post-transplantation revaccination uptake of childhood vaccines in adult hematopoietic stem cell transplantation (HSCT) survivors is suboptimal, increasing the risk of infectious morbidity and mortality within this population. We systematically reviewed the literature for factors related to revaccination uptake, as well as the barriers and facilitators that affect successful revaccination. We conducted a scoping review searching PubMed, CINAHL, Embase, and Web of Science in March 2023. Two independent reviewers performed study selection using the complete dual review process. Data were extracted using a standard form. Factors were characterized as demographic, clinical, or social determinants of health that affected revaccination uptake. Barriers and facilitators were categorized using the constructs from the World Health Organization Behavioural and Social Drivers Framework. Our searches yielded 914 sources, from which 15 publications were selected (5 original research and 10 quality improvement initiatives). More than one-half of the reports listed factors associated with poorer uptake, predominately clinical factors, followed by social determinants of health, then demographic factors. Nearly all the reports described barriers to successful revaccination uptake, with most of these falling into the "practical issues" construct. Most of the reports described facilitators, nearly all related to health care system improvements associated with improved revaccination uptake. Although this review provides a good starting point for understanding impediments to successful revaccination after HSCT, this review reveals that we lack sufficient evidence to drive targeted interventions to improve uptake. More research is needed, focusing on survivors' voices to inform our knowledge of barriers and facilitators to complete revaccination after HSCT, exploring behavioral and social drivers within this population, and examining the care delivery models that may complicate vaccine delivery in this population.

ERS/EBMT clinical practice guidelines on treatment of pulmonary chronic graft-versus-host disease in adults

Chronic graft-versus-host disease (cGvHD) is a common complication after allogeneic haematopoietic stem cell transplantation, characterised by a broad disease spectrum that can affect virtually any organ. Although pulmonary cGvHD is a less common manifestation, it is of great concern due to its severity and poor prognosis. Optimal management of patients with pulmonary cGvHD is complicated and no standardised approach is available. The purpose of this joint European Respiratory Society (ERS) and European Society for Blood and Marrow Transplantation task force was to develop evidence-based recommendations regarding the treatment of pulmonary cGvHD phenotype bronchiolitis obliterans syndrome in adults. A multidisciplinary group representing specialists in haematology, respiratory medicine and methodology, as well as patient advocates, formulated eight PICO (patient, intervention, comparison, outcome) and two narrative questions. Following the ERS standardised methodology, we conducted systematic reviews to address these questions and used the Grading of Recommendations Assessment, Development and Evaluation approach to develop recommendations. The resulting guideline addresses common therapeutic options (inhalation therapy, fluticasone-azithromycin-montelukast, imatinib, ibrutinib, ruxolitinib, belumosudil, extracorporeal photopheresis and lung transplantation), as well as other aspects of general management, such as lung functional and radiological follow-up and pulmonary rehabilitation, for adults with pulmonary cGvHD phenotype bronchiolitis obliterans syndrome. These recommendations include important advancements that could be incorporated in the management of adults with pulmonary cGvHD, primarily aimed at improving and standardising treatment and improving outcomes.

Comparable CD8+ T-cell responses to SARS-CoV-2 vaccination in single-cell transcriptomics of recently allogeneic transplanted patients and healthy individuals

Despite extensive research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination responses in healthy individuals, there is comparatively little known beyond antibody titers and T-cell responses in the vulnerable cohort of patients after allogeneic hematopoietic stem cell transplantation (ASCT). In this study, we assessed the serological response and performed longitudinal multimodal analyses including T-cell functionality and single-cell RNA sequencing combined with T cell receptor (TCR)/B cell receptor (BCR) profiling in the context of BNT162b2 vaccination in ASCT patients. In addition, these data were compared to publicly available data sets of healthy vaccinees. Protective antibody titers were achieved in 40% of patients. We identified a distorted B- and T-cell distribution, a reduced TCR diversity, and increased levels of exhaustion marker expression as possible causes for the poorer vaccine response rates in ASCT patients. Immunoglobulin heavy chain gene rearrangement after vaccination proved to be highly variable in ASCT patients. Changes in TCRα and TCRβ gene rearrangement after vaccination differed from patterns observed in healthy vaccinees. Crucially, ASCT patients elicited comparable proportions of SARS-CoV-2 vaccine-induced (VI) CD8+ T-cells, characterized by a distinct gene expression pattern that is associated with SARS-CoV-2 specificity in healthy individuals. Our study underlines the impaired immune system and thus the lower vaccine response rates in ASCT patients. However, since protective vaccine responses and VI CD8+ T-cells can be induced in part of ASCT patients, our data advocate early posttransplant vaccination due to the high risk of infection in this vulnerable group.

Pre-Transplantation Strategies for Infectious Disease Mitigation and Prevention

Pediatric Infectious Disease (ID) clinicians play a critical role in helping prevent and mitigate infectious risks in children peri- and post-transplantation. Prevention starts during the pre-transplant evaluation and persists throughout the solid organ transplant and hematopoietic cell transplant continuum. The pre-transplant evaluation is an opportunity to screen for latent infections, plan preventative strategies, optimize immunizations, and discuss risk mitigation practices. An ideal pre-transplant evaluation establishes a relationship with the family that further promotes post-transplant infectious risk reduction. This manuscript builds on shared pediatric ID prevention strategies, introduces updated ID testing recommendations for transplant donors/candidates, highlights emerging data, and identifies ongoing knowledge gaps that are potential areas of research.

International recommendations for screening and preventative practices for long-term survivors of transplantation and cellular therapy: a 2023 update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the volume of HCT performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long-term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pre-, peri- and post-transplant exposures and other underlying risk-factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and updated in 2012. To review contemporary literature and update the recommendations while considering the changing practice of HCT and cellular therapy, an international group of experts was again convened. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed but cGVHD management is not covered in detail. These guidelines emphasize special needs of patients with distinct underlying HCT indications or comorbidities (e.g., hemoglobinopathies, older adults) but do not replace more detailed group, disease, or condition specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

French protocol for the diagnosis and management of hematopoietic stem cell transplantation in autoimmune diseases

Hematopoietic stem cell transplantation (HSCT) for severe ADs was developed over the past 25years and is now validated by national and international medical societies for severe early systemic sclerosis (SSc) and relapsing-remitting multiple sclerosis (MS) and available as part of routine care in accredited center. HSCT is also recommended, with varying levels of evidence, as an alternative treatment for several ADs, when refractory to conventional therapy, including specific cases of connective tissue diseases or vasculitis, inflammatory neurological diseases, and more rarely severe refractory Crohn's disease. The aim of this document was to provide guidelines for the current indications, procedures and follow-up of HSCT in ADs. Patient safety considerations are central to guidance on patient selection and conditioning, always validated at the national MATHEC multidisciplinary team meeting (MDTM) based on recent (less than 3months) thorough patient evaluation. HSCT procedural aspects and follow-up are then carried out within appropriately experienced and Joint Accreditation Committee of International Society for Cellular Therapy and SFGM-TC accredited centres in close collaboration with the ADs specialist. These French recommendations were performed according to HAS/FAI2R standard operating procedures and coordinated by the Île-de-France MATHEC Reference Centre for Rare Systemic Autoimmune Diseases (CRMR MATHEC) within the Filière FAI2R and in association with the Filière MaRIH. The task force consisted of 3 patients and 64 clinical experts from various specialties and French centres. These data-derived and consensus-derived recommendations will help clinicians to propose HSCT for their severe ADs patients in an evidence-based way. These recommendations also give directions for future clinical research in this area. These recommendations will be updated according to newly emerging data. Of note, other cell therapies that have not yet been approved for clinical practice or are the subject of ongoing clinical research will not be addressed in this document.

[Vaccination of allogeneic haematopoietic stem cell transplant recipients: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

During immune reconstitution following allogeneic haematopoietic stem cell transplantation (allo-HSCT), (re)vaccination of allo-HSCT recipients is recommended. Herein, we propose an update of practical recommendations regarding vaccination of allo-HSCT recipients. These recommendations, based on data from the literature, national and international guidelines and the consensus of the participants when no formally proven data are available, were elaborated during the workshop of practice harmonization organized by the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) in Lille in September 2022.

Vaccine response after pneumococcal vaccination in allogeneic hematopoietic stem cell transplant recipients

Current guidelines for vaccination in allogeneic hematopoietic stem cell transplant (HCT) recipients recommend initiation of pneumococcal vaccination series three to six months post-HCT, with most data supporting initiation at six months due to a more robust immune response. This single-center, retrospective, observational chart review aimed to evaluate the impact of initiating the pneumococcal vaccine series at three months post-HCT compared to six months post-HCT. The primary endpoints were defined as a percentage of patients with a serologic response of >1 and >1.3 µg/mL for over 50% of the defined serotypes. Outcomes showed no difference in immunologic response between the two groups.

Consensus document of the Spanish Society of Paediatric Infectious Diseases and the Advisory Committee on Vaccines of the Spanish Association of Pediatrics for vaccination of immunosuppressed individuals

The number of people with immunosuppression is increasing considerably due to their greater survival and the use of new immunosuppressive treatments for various chronic diseases. This is a heterogeneous group of patients in whom vaccination as a preventive measure is one of the basic pillars of their wellbeing, given their increased risk of contracting infections. This consensus, developed jointly by the Sociedad Española de Infectología Pediátrica (Spanish Society of Pediatric Infectious Diseases) and the Advisory Committee on Vaccines of the Asociación Española de Pediatría (Spanish Association of Paediatrics), provides guidelines for the development of a personalised vaccination schedule for patients in special situations, including general recommendations and specific recommendations for vaccination of bone marrow and solid organ transplant recipients, children with inborn errors of immunity, oncologic patients, patients with chronic or systemic diseases and immunosuppressed travellers.

Vaccination practices in pediatric transplantation: A survey among member centers of the European reference network TransplantChild

BACKGROUND

There is considerable variation in vaccination practices between pediatric transplant centers. This study aims to evaluate active immunization attitudes and practices among ERN-TransplantChild centers and identify potential areas of improvement that could be addressed by shared evidence-based protocols.

METHODS

A cross-sectional questionnaire of attitudes and practices toward immunization of pediatric SOT and HSCT candidates and recipients was sent to a representative member of multidisciplinary teams from 27 European centers belonging to the ERN-TransplantChild.

RESULTS

A total of 28/62 SOT programs and 6/12 HSCT programs across 21 European centers participated. A quarter of centers did not have an on-site protocol for the immunizations. At the time of transplantation, pediatric candidates were fully immunized (80%-100%) in 57% and 33% of the SOT and HSCT programs. Variations in the time between vaccine administration and admission to the waiting list were reported between the centers, with 2 weeks for inactivated vaccines and variable time (2-4 weeks) for live-attenuated vaccines (LAVs). Almost all sites recommended immunization in the post-transplant period, with a time window of 4-8 months for the inactivated vaccines and 16-24 months for MMR and Varicella vaccines. Only five sites administer LAVs after transplantation, with seroconversion evaluated in 80% of cases.

CONCLUSIONS

The immunization coverage of European pediatric transplant recipients is still inconsistent and far from adequate. This survey is a starting point for developing shared evidence-based immunization protocols for safe vaccination among pediatric transplant centers and generating new research studies.

Targeting enhanced neutralizing antibody responses via increased germinal center activity: early-phase vaccine trials with novel clinical designs

PURPOSE OF REVIEW

Recent advances in the understanding of the difficult immunologic requirements for the induction of broadly neutralizing antibodies for HIV have spurred interest in optimizing vaccine approaches intended to stimulate a robust germinal center reaction. In preclinical models, techniques to optimize the germinal center response have included alterations in the timing, dose, and delivery method of immunogens and have resulted in substantially enhanced germinal center responses in lymph nodes and neutralizing antibodies in serum. One of the most promising approaches involves splitting the initial dose of vaccine into a series of gradual escalating doses administration ("fractional escalating doses"). In principle, these techniques may have broad implications for vaccines targeting a robust antibody response.

RECENT FINDINGS

We review the upcoming vaccine trials that will test these concepts in clinical practice. The trials include both HIV and non-HIV immunogens, and will involve testing these concepts in both healthy adults and immunocompromised persons.

SUMMARY

There are multiple trials that will test whether techniques to alter vaccine delivery such as fractional escalating doses enhances immunologic outcomes.

A Phase 3, Randomized, Double-Blind, Comparator-Controlled Study to Evaluate Safety, Tolerability, and Immunogenicity of V114, a 15-Valent Pneumococcal Conjugate Vaccine, in Allogeneic Hematopoietic Cell Transplant Recipients (PNEU-STEM)

BACKGROUND

Individuals who receive allogeneic hematopoietic cell transplant (allo-HCT) are immunocompromised and at high risk of pneumococcal infections, especially in the months following transplant. This study evaluated the safety and immunogenicity of V114 (VAXNEUVANCE; Merck, Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA), a 15-valent pneumococcal conjugate vaccine (PCV), when given to allo-HCT recipients.

METHODS

Participants received 3 doses of V114 or PCV13 (Prevnar 13; Wyeth LLC) in 1-month intervals starting 3-6 months after allo-HCT. Twelve months after HCT, participants received either PNEUMOVAX 23 or a fourth dose of PCV (if they experienced chronic graft vs host disease). Safety was evaluated as the proportion of participants with adverse events (AEs). Immunogenicity was evaluated by measuring serotype-specific immunoglobulin G (IgG) geometric mean concentrations (GMCs) and opsonophagocytic activity (OPA) geometric mean titers (GMTs) for all V114 serotypes in each vaccination group.

RESULTS

A total of 274 participants were enrolled and vaccinated in the study. The proportions of participants with AEs and serious AEs were generally comparable between intervention groups, and the majority of AEs in both groups were of short duration and mild-to-moderate intensity. For both IgG GMCs and OPA GMTs, V114 was generally comparable to PCV13 for the 13 shared serotypes, and higher for serotypes 22F and 33F at day 90.

CONCLUSIONS

V114 was well tolerated in allo-HCT recipients, with a generally comparable safety profile to PCV13. V114 induced comparable immune responses to PCV13 for the 13 shared serotypes, and was higher for V114 serotypes 22F and 33F. Study results support the use of V114 in allo-HCT recipients. Clinical Trials Registration. clinicaltrials.gov (NCT03565900) and European Union at EudraCT 2018-000066-11.

Self-care guidelines for patients in the post-hematopoietic stem cell transplantation period: a scoping review

OBJECTIVE

To map the evidence on self-care guidelines for patients in the post-hematopoietic stem cell transplantation (HSCT) period.

METHOD

Scoping review supported by Joanna Briggs Institute recommendations, with searches conducted between March and April 2022 in national and international databases and repositories of theses and dissertations.

RESULTS

Of the 11 studies that composed the final sample, the guidelines had a social and personal aspect, as post-transplant patients need to follow numerous essential recommendations for the prevention of infections and complications for successful treatment and improved quality of life.

CONCLUSION

Knowing the self-care guidelines that must be performed by post-HSCT patients is fundamental for the nursing team to provide the necessary information for care outside the controlled environment of the hospital, in addition to minimizing episodes of infection, death, and increasing the survival and quality of life of transplant recipients.

High Rates of Seroprotection and Seroconversion to Vaccine-Preventable Infections in the Early Post-Autologous Stem Cell Transplant Period

In patients early post-autologous stem cell transplant, seroprotection rates were high for Hemophilus influenzae type B and tetanus toxoid (70%-90%) but lower for Streptococcus pneumoniae (30%-50%) including after revaccination. There were high rates of seropositivity (67%-86%) to measles, mumps, and rubella and varicella zoster virus. Durability of protection requires assessment.

Attenuated immunogenicity of SARS-CoV-2 vaccines and risk factors in stem cell transplant recipients: a meta-analysis

Immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is diminished in hematopoietic stem cell transplant (HSCT) recipients. To summarize current evidence and identify risk factors for attenuated responses, 5 electronic databases were searched since database inceptions through 12 January 2023 for studies reporting humoral and/or cellular immunogenicity of SARS-CoV-2 vaccination in the HSCT population. Using descriptive statistics and random-effects models, extracted numbers of responders and pooled odds ratios (pORs) with 95% confidence intervals (CIs) for risk factors of negative immune responses were analyzed (PROSPERO: CRD42021277109). From 61 studies with 5906 HSCT recipients, after 1, 2, and 3 doses of messenger RNA (mRNA) SARS-CoV-2 vaccines, the mean antispike antibody seropositivity rates (95% CI) were 38% (19-62), 81% (77-84), and 80% (75-84); neutralizing antibody seropositivity rates were 52% (40-64), 71% (54-83), and 78% (61-89); and cellular immune response rates were 52% (39-64), 66% (51-79), and 72% (52-86). After 2 vaccine doses, risk factors (pOR; 95% CI) associated with antispike seronegativity were male recipients (0.63; 0.49-0.83), recent rituximab exposure (0.09; 0.03-0.21), haploidentical allografts (0.46; 0.22-0.95), <24 months from HSCT (0.25; 0.07-0.89), lymphopenia (0.18; 0.13-0.24), hypogammaglobulinemia (0.23; 0.10-0.55), concomitant chemotherapy (0.48; 0.29-0.78) and immunosuppression (0.18; 0.13-0.25). Complete remission of underlying hematologic malignancy (2.55; 1.05-6.17) and myeloablative conditioning (1.72; 1.30-2.28) compared with reduced-intensity conditioning were associated with antispike seropositivity. Ongoing immunosuppression (0.31; 0.10-0.99) was associated with poor cellular immunogenicity. In conclusion, attenuated humoral and cellular immune responses to mRNA SARS-CoV-2 vaccination are associated with several risk factors among HSCT recipients. Optimizing individualized vaccination and developing alternative COVID-19 prevention strategies are warranted.

Real-world challenges in eligibility for MMR vaccination two years after autologous and allogeneic HSCT

Measles outbreaks have raised concerns of fatal infections in immunocompromised patients. Canadian guidelines advise administration of live vaccines, such as measles, mumps, and rubella (MMR), two yearsafter hematopoietic stem cell transplant (HSCT) yet studies have not assessed eligibility based on medication contraindications. We retrospectively reviewed the charts of 72 autologous (auto-HSCT) and 68 allogeneic (allo-HSCT) recipients at the Windsor Regional Cancer Center to determine MMR reactivity and eligibility based on administration of contraindicated medications two years post-HSCT. Reactivity to measles, mumps, and rubella in auto-HSCT recipients was 49.1 %, 28.8 %, and 52.3 %, respectively, and in allo-HSCT recipients was 75.6 %, 57.8 %, and 64.4 %, respectively. Immunity to all three components was significantly different between transplant types (p = 0.0002). Nearly 80 % of auto-HSCT patients were on a contraindicated medication at two years compared to 45 % of allo-HSCT recipients. Auto-HSCT recipients require MMR revaccination, but it is contraindicated in a large proportion of patients.

Acute exacerbation of ocular graft-versus-host disease and anterior uveitis after COVID-19 vaccination

BACKGROUND

To report a case of simultaneous occurrence of acute exacerbation of ocular graft-versus-host disease (GVHD) and anterior uveitis following coronavirus disease 2019 (COVID-19) vaccination.

CASE PRESENTATION

A 60-year-old man with primary myelofibrosis and GVHD after receiving allogeneic hematopoietic stem cell transplantation (HSCT), developed acute exacerbation of ocular GVHD and anterior uveitis after receiving first dose of COVID-19 vaccine. The patient developed erythema of the eyelids, conjunctival hyperemia, superficial punctate keratopathy, and prominent anterior chamber inflammation in both eyes. The ocular GVHD and anterior uveitis were managed with mainly topical corticosteroids, antibiotics, lubricants, and systemic corticosteroids, but were difficult to control. Intravitreal injection of dexamethasone was administered, and the inflammation gradually subsided 6 months after the onset of initial symptoms.

CONCLUSIONS

Clinicians should be aware of rare refractory anterior uveitis and acute exacerbation of ocular GVHD after COVID-19 vaccination in patients undergoing HSCT. Early diagnosis and aggressive treatment should be considered to reduce the likelihood of severe complications.

Compliance with yellow fever and measles vaccines in the revaccination program post-hematopoietic cell transplantation

INTRODUCTION

Measles, mumps, rubella, and even poliomyelitis outbreaks have recently perplexed infectious disease clinicians and epidemiologists globally due to the decline in vaccination coverage rates in children and adults. Measles and yellow fever (YF) have represented an increasing burden on the Brazilian public health system in recent decades. Both diseases are preventable by live-attenuated viral vaccines (LAVV), which have restricted use in hematopoietic cell transplant (HCT) recipients.

METHODS

Autologous and allogeneic HCT recipients returning for regular appointments at the outpatient clinic were invited to participate in the study. Patients transplanted for at least 2 years and with a printed copy of the vaccination record were included.

RESULTS

We assessed the vaccination records of 273 HCT recipients after the second year of HCT (193 allogeneic and 80 autologous) and observed lower compliance with the YF vaccine (58 patients, 21.2%) than with the measles vaccine (138 patients, 50.5%, p ≤ .0001). This is the largest published series of YF vaccination in HCT recipients so far. No severe adverse events occurred. Although expected, chronic graft-versus-host disease (GVHD) did not affect the compliance with measles (p = .08) or YF vaccination (p = .7). Indeed, more allogeneic recipients received measles vaccine in comparison with autologous patients (p < .0001), suggesting that chronic GVHD was not the main reason for not being vaccinated. Children and allogeneic HCT were more likely to receive measles vaccine. Time elapsed from HCT >5 years favored both measles and YF vaccination.

CONCLUSION

A better understanding of the reasons for low compliance with LAVV is necessary to overcome this problem.

ECTRIMS/EAN consensus on vaccination in people with multiple sclerosis: Improving immunization strategies in the era of highly active immunotherapeutic drugs

BACKGROUND

With the new highly active drugs available for people with multiple sclerosis (pwMS), vaccination becomes an essential part of the risk management strategy.

OBJECTIVE

To develop a European evidence-based consensus for the vaccination strategy of pwMS who are candidates for disease-modifying therapies (DMTs).

METHODS

This work was conducted by a multidisciplinary working group using formal consensus methodology. Clinical questions (defined as population, interventions, and outcomes) considered all authorized DMTs and vaccines. A systematic literature search was conducted and quality of evidence was defined according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence. The recommendations were formulated based on the quality of evidence and the risk-benefit balance.

RESULTS

Seven questions, encompassing vaccine safety, vaccine effectiveness, global vaccination strategy and vaccination in sub-populations (pediatric, pregnant women, elderly and international travelers) were considered. A narrative description of the evidence considering published studies, guidelines, and position statements is presented. A total of 53 recommendations were agreed by the working group after three rounds of consensus.

CONCLUSION

This first European consensus on vaccination in pwMS proposes the best vaccination strategy according to current evidence and expert knowledge, with the goal of homogenizing the immunization practices in pwMS.

Pediatric cancer care management during the COVID-19 pandemic: a review of the literature and a single-centre real-life experience of an Italian pediatric oncology unit

INTRODUCTION

The severe acute respiratory syndrome coronavirus-2 pandemic significantly affected clinical practice, also in pediatric oncology units. Cancer patients needed to be treated with an adequate dose density despite the SARS-CoV-2 infection, balancing risks of developing severe COVID-19 disease.

AREAS COVERED

Although the pandemic spread worldwide, the prevalence of affected children was low. The percentage of children with severe illness was approximately 1-6%. Pediatric cancer patients represent a prototype of a previously healthy immune system that is hampered by the tumor itself and treatments, such as chemotherapy and steroids. Through a review of the literature, we reported the immunological basis of the response to SARS-CoV-2 infection, the existing antiviral treatments used in pediatric cancer patients, and the importance of vaccination. In conclusion, we reported the real-life experience of our pediatric oncology unit during the pandemic period.

EXPERT OPINION

Starting from the data available in literature, and our experience, showing the rarity of severe COVID-19 disease in pediatric patients with solid tumors, we recommend carefully tailoring all the oncological treatments (chemotherapy/targeted therapy/stem cell transplantation/radiotherapy). The aim is the preservation of the treatment's timing, balanced with an evaluation of possible severe COVID-19 disease.

Acute graft-versus-host disease

Acute graft-versus-host disease (GVHD) is a common immune complication that can occur after allogeneic haematopoietic cell transplantation (alloHCT). Acute GVHD is a major health problem in these patients, and is associated with high morbidity and mortality. Acute GVHD is caused by the recognition and the destruction of the recipient tissues and organs by the donor immune effector cells. This condition usually occurs within the first 3 months after alloHCT, but later onset is possible. Targeted organs include the skin, the lower and upper gastrointestinal tract and the liver. Diagnosis is mainly based on clinical examination, and complementary examinations are performed to exclude differential diagnoses. Preventive treatment for acute GVHD is administered to all patients who receive alloHCT, although it is not always effective. Steroids are used for first-line treatment, and the Janus kinase 2 (JAK2) inhibitor ruxolitinib is second-line treatment. No validated treatments are available for acute GVHD that is refractory to steroids and ruxolitinib, and therefore it remains an unmet medical need.

Spotlight on the impact of viral infections on Hematopoietic Stem Cells (HSCs) with a focus on COVID-19 effects

Hematopoietic stem cells (HSCs) are known for their significant capability to reconstitute and preserve a functional hematopoietic system in long-term periods after transplantation into conditioned hosts. HSCs are thus crucial cellular targets for the continual repair of inherited hematologic, metabolic, and immunologic disorders. In addition, HSCs can undergo various fates, such as apoptosis, quiescence, migration, differentiation, and self-renewal. Viruses continuously pose a remarkable health risk and request an appropriate, balanced reaction from our immune system, which as well as affects the bone marrow (BM). Therefore, disruption of the hematopoietic system due to viral infection is essential. In addition, patients for whom the risk-to-benefit ratio of HSC transplantation (HSCT) is acceptable have seen an increase in the use of HSCT in recent years. Hematopoietic suppression, BM failure, and HSC exhaustion are all linked to chronic viral infections. Virus infections continue to be a leading cause of morbidity and mortality in HSCT recipients, despite recent advancements in the field. Furthermore, whereas COVID-19 manifests initially as an infection of the respiratory tract, it is now understood to be a systemic illness that significantly impacts the hematological system. Patients with advanced COVID-19 often have thrombocytopenia and blood hypercoagulability. In the era of COVID-19, Hematological manifestations of COVID-19 (i.e., thrombocytopenia and lymphopenia), the immune response, and HSCT may all be affected by the SARS-CoV-2 virus in various ways. Therefore, it is important to determine whether exposure to viral infections may affect HSCs used for HSCT, as this, in turn, may affect engraftment efficiency. In this article, we reviewed the features of HSCs, and the effects of viral infections on HSCs and HSCT, such as SARS-CoV-2, HIV, cytomegalovirus, Epstein-Barr virus, HIV, etc. Video Abstract.

SARS-CoV-2 vaccination in the first year after allogeneic hematopoietic cell transplant: a prospective, multicentre, observational study

Background

The optimal timing for SARS-CoV-2 vaccines within the first year after allogeneic hematopoietic cell transplant (HCT) is poorly understood.

Methods

We conducted a prospective, multicentre, observational study of allogeneic HCT recipients who initiated SARS-CoV-2 vaccinations within 12 months of HCT. Participants were enrolled at 22 academic cancer centers across the United States. Participants of any age who were planning to receive a first post-HCT SARS-CoV-2 vaccine within 12 months of HCT were eligible. We obtained blood prior to and after each vaccine dose for up to four vaccine doses, with an end-of-study sample seven to nine months after enrollment. We tested for SARS-CoV-2 spike protein (anti-S) IgG; nucleocapsid protein (anti-N) IgG; neutralizing antibodies for Wuhan D614G, Delta B.1.617.2, and Omicron B.1.1.529 strains; and SARS-CoV-2-specific T-cell receptors (TCRs). The primary outcome was a comparison of anti-S IgG titers at the post-V2 time point in participants initiating vaccinations <4 months versus 4-12 months after HCT using a propensity-adjusted analysis. We also evaluated factors associated with high-level anti-S IgG titers (≥2403 U/mL) in logistic regression models.

Findings

Between April 22, 2021 and November 17, 2021, 175 allogeneic HCT recipients were enrolled in the study, of whom all but one received mRNA SARS-CoV-2 vaccines. SARS-CoV-2 anti-S IgG titers, neutralizing antibody titers, and TCR breadth and depth did not significantly differ at all tested time points following the second vaccination among those initiating vaccinations <4 months versus 4-12 months after HCT. Anti-S IgG ≥2403 U/mL correlated with neutralizing antibody levels similar to those observed in a prior study of non-immunocompromised individuals, and 57% of participants achieved anti-S IgG ≥2403 U/mL at the end-of-study time point. In models adjusted for SARS-CoV-2 infection pre-enrollment, SARS-CoV-2 vaccination pre-HCT, CD19+ B-cell count, CD4+ T-cell count, and age (as applicable to the model), vaccine initiation timing was not associated with high-level anti-S IgG titers at the post-V2, post-V3, or end-of-study time points. Notably, prior graft-versus-host-disease (GVHD) or use of immunosuppressive medications were not associated with high-level anti-S IgG titers. Grade ≥3 vaccine-associated adverse events were infrequent.

Interpretation

These data support starting mRNA SARS-CoV-2 vaccination three months after HCT, irrespective of concurrent GVHD or use of immunosuppressive medications. This is one of the largest prospective analyses of vaccination for any pathogen within the first year after allogeneic HCT and supports current guidelines for SARS-CoV-2 vaccination starting three months post-HCT. Additionally, there are few studies of mRNA vaccine formulations for other pathogens in HCT recipients, and these data provide encouraging proof-of-concept for the utility of early vaccination targeting additional pathogens with mRNA vaccine platforms.

Funding

National Marrow Donor Program, Leukemia and Lymphoma Society, Multiple Myeloma Research Foundation, Novartis, LabCorp, American Society for Transplantation and Cellular Therapy, Adaptive Biotechnologies, and the National Institutes of Health.

Persistent Immunity against SARS-CoV-2 in Individuals with Oncohematological Diseases Who Underwent Autologous or Allogeneic Stem Cell Transplantation after Vaccination

The high morbimortality due to SARS-CoV-2 infection in oncohematological diseases (OHD) and hematopoietic stem cell transplant (HSCT) recipients in the pre-vaccine era has made vaccination a priority in this group. After HSCT, the immune responses against common vaccines such as tetanus, varicella, rubella, and polio may be lost. However, the loss of immunity developed by COVID-19 vaccination after HSCT has not been completely defined. In this study, both humoral and cellular immunity against SARS-CoV-2 were analyzed in 29 individuals with OHD who were vaccinated before receiving allogeneic (n = 11) or autologous (n = 18) HSCT. All participants had low but protective levels of neutralizing IgGs against SARS-CoV-2 after HSCT despite B-cell lymphopenia and immaturity. Although antibody-dependent cellular cytotoxicity was impaired, direct cellular cytotoxicity was similar to healthy donors in participants with autologous-HSCT, in contrast to individuals with allogeneic-HSCT, which severely deteriorated. No significant changes were observed in the immune response before and after HSCT. During follow-up, all reported post-HSCT SARS-CoV-2 infections were mild. This data emphasizes that COVID-19 vaccination is effective, necessary, and safe for individuals with OHD and also supports the persistence of some degree of immune protection after HSCT, at least in the short term, when patients cannot yet be revaccinated.

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.

COVID-19 in Adult Patients with Hematological Malignancies-Lessons Learned after Three Years of Pandemic

The COVID-19 pandemic is undoubtedly the most difficult health challenge of the 21st century with more than 600 million laboratory-confirmed SARS-CoV-2 infections and over 6.5 million deaths worldwide. The coronavirus pandemic contributed to rapid development of mRNA vaccines, which, along with new antiviral drugs, have been the subject of extensive research for many decades. Nevertheless, elderly, multi-morbid and immunocompromised patients continue to face a more severe clinical course and a higher risk of death from COVID-19, even now that the risk of COVID-19 in the general population is significantly reduced due to the introduction of global vaccination strategies. In this paper, we present the mechanisms of increased susceptibility to infectious complications and the evolution of the clinical course of COVID-19 in patients with hematological malignancies, taking into account the mutation of the virus and the introduction of vaccines and new antiviral drugs. We also present current recommendations for prophylactic and therapeutic management in patients with hematological malignancies.

Pneumococcal Conjugate Vaccine Does Not Induce Humoral Response When Administrated Within the Six Months After CD19 CAR T-Cell Therapy

CD19 targeted chimeric antigen receptor-modified T cell therapy (CAR-T) leads to B cell aplasia and low serum immunoglobulin levels. Long-lived CD19-negative plasma cells may persist through the therapy and generate antibodies. There is a paucity of data describing how CAR-T impacts the persistence of antibodies against vaccine-related antigens and the degree to which CAR-T recipients may respond to vaccines. We characterized the effect of CAR-T on pneumococcal immunoglobulin G (IgG) titers and determine whether pneumococcal conjugate vaccine (PCV13) administered after CAR-T develops long-term humoral protection against pneumococcus. A retrospective chart review was performed to identify CAR-T recipients who had serum pneumococcal IgG titers drawn before (baseline) or at days +90, +180, +270, +360, or +540 after CAR-T. We then determined whether they received PCV13 vaccination at these timepoints. IgG concentration ≥1.3 μg/mL was considered protective for that serotype, and patients with ≥6/11 tested vaccine-specific serotypes meeting this threshold were deemed to have humoral protection against pneumococcus. Absolute pneumococcal IgG titers and the proportion of patients with humoral protection, stratified by serotype, and vaccination status were compared by paired nonparametric t-tests. Absolute counts for lymphocyte, CD4 T-cell, and CD19 cell and total IgG level, along with the rate of invasive pneumococcal infections, were measured at these timepoints. A total of 148 CAR-T recipients with pneumococcal IgG titers measured for at least one of the defined time points were identified. At baseline, 25% (19/76) patients with evaluable pneumococcal IgG titers met the definition of humoral protection. Among 44 patients with paired pneumococcal IgG titers at baseline and day+90, absolute IgG titers of all serotypes decreased (geometric mean = 0.41 and 0.32 µg/mL, respectively; P < .001). Thirteen patients were vaccinated following the titer blood draw at day+90 and had paired pneumococcal IgG titers at day+90 and day180. Absolute IgG titers of all vaccine specific serotypes in these vaccinated patients decreased from day+90 to day+180 (geometric mean = 0.36 and 0.29 µg/mL, respectively; P = .03). The proportion of patients meeting the criteria of humoral protection remained the same at day+180 despite vaccination at day+90. The results were similar among 8 patients vaccinated at day+180, as well as 7 patients consecutively vaccinated at day+90 and day+180 with corresponding pneumococcal IgG titers. When all vaccine-specific pneumococcal IgG titers were pooled together by timepoint regardless of vaccination status, the proportion of patients with humoral protection decreased until day+540. Some patients developed humoral protection after vaccination at day+360, maintained seroprotective IgG titers from baseline, or developed protection after receiving intravenous immunoglobulin treatment secondary to recurrent infections. Our study demonstrated that few large B cell lymphoma patients had humoral protection against pneumococcus at baseline, and existing IgG titers decreased after CAR-T. PCV13 vaccination at day+90 or day+180 after CAR-T did not increase humoral protection against pneumococcus. Only at day+540 was there evidence of humoral protection against pneumococcus in a modest proportion of patients. Clinical trials are needed to determine the optimal timing of vaccination, before or after CAR-T, to develop protective immunity against Streptococcus pneumoniae infections.

Vaccine Adherence and Postvaccination Serological Status of Pediatric Allogeneic Hematopoietic Stem Cell Transplant Recipients: A Single-center Experience

Despite developing consensus guidelines addressing immunization after hematopoietic stem cell transplantation (HSCT), studies showed deviations from recommended immunization practices commonly occur. Difference between the ideal scenario presented in guidelines and real-life scenarios is one of the most recognized barriers to implementing recommended practices. Therefore, this study aimed to evaluate pediatric allogeneic HSCT recipients' adherence to revaccination schedule and evaluate the serological status after immunization. Transplant and vaccination records of children who were followed up at least 2 years after HSCT, postvaccination antibody results of vaccine-preventable diseases were evaluated retrospectively. Total of 173 patients have enrolled in this study. Median revaccination onset time was post-transplant 15 months. Adherence to revaccination program was 30% for inactive and 11.4% for live vaccines. Oral polio vaccine was given to 22 patients, and Bacille-Calmette-Guerin vaccine was applied to 3. Seropositivity after revaccination was >90% for Hepatitis B, Hepatitis A, pertussis, and measles, and it was 88.5% for rubella, 80% for mumps and varicella. Measles seropositivity was low in children with hemoglobinopathy. In subgroup assessments of pertussis, patients vaccinated with low antigen-containing pertussis vaccine (Tdap) had higher seropositivity of adenylate cyclase toxin. Our findings revealed the importance of careful monitoring of current practices in pediatric HSCT recipients.

Long-Term Immunity Against Tetanus and Diphtheria after Vaccination of Allogeneic Stem Cell Transplantation Recipients

Revaccination against tetanus and diphtheria after allogeneic hematopoietic stem cell transplantation (HCT) is usually effective, but the duration of the immunity is unknown. We conducted this study to evaluate humoral immunity to tetanus and diphtheria in long-term survivors and to provide knowledge regarding the need for boosters. The median time from HCT to blood sampling was 14 years (range, 8 to 40 years). All patients had received at least 3 doses of vaccines against both tetanus and diphtheria, either monovalent or combination vaccines containing a full dose of the diphtheria toxoid component. In addition, 1 or more booster doses were administered to 21 of the 146 patients (14%). On enzyme-linked immunosorbent assay, levels <.1 IU/mL for diphtheria and <.01 IU/mL for tetanus were considered low or seronegative. Values between .01 and .5 IU/mL for tetanus and between .1 and 1.0 IU/mL for diphtheria were considered to represent partial protection, and levels >.5 and >1.0 IU/mL were considered high and protective, respectively. In all, 39% of patients were seronegative against diphtheria, 52% had some protection, and 9% had a high titer. In contrast, no patient had become seronegative to tetanus, 32% had "partial protection" against tetanus and 68% had a high titer. In multivariate analysis, active graft-versus-host-disease, sex, or time from sampling did not affect the probability of becoming seronegative or seropositive. Younger age was associated with lower antibody levels to tetanus toxoid, but age was not correlated with antibody levels against diphtheria toxoid. Tetanus immunity was maintained after vaccination in most long-term survivors, but immunity against diphtheria was poor, and boosters should be considered.

Adoptive immune transfer from donors offers Anti-HBV protection to HBsAb-negative patients after Allo-HSCT

Adoptive transfer of hepatitis B virus (HBV) immunity may occur following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here, we investigated the adoptive transfer of HBV immunity in 112 patients without HBV surface antibody (HBsAb) (HBsAb-) at the time of their first allo-HSCT. After allo-HSCT, HBV-DNA（87.5%） and HBsAg（11.1%%）cleared in HBsAg+ patients. All HBsAg- patients acquired HBsAb immediately. Nevertheless, HBsAb titers subsequently declined, and 39/67 (58.2%) patients lost HBsAb during follow-up. The 5-year overall survival (OS) was better in patients who lost HBsAb. Multivariate analysis showed that the independent risk factors for OS were lack of cytomegalovirus (CMV) clearance, acute graft-versus-host disease (aGVHD), and no HBsAb loss. Overall, adoptive immune transfer offers anti-HBV protection to patients without HBsAb, as they acquire HBsAb and clear HBV-DNA and HBsAg, while HBsAb loss after allo-HSCT predicts better survival.

Influence of Acute and Chronic Graft-Versus-Host Disease on Persistence of Antibodies against Measles, Mumps, Rubella and Varicella in the First Year after Autologous or Allogeneic Hematopoietic Stem Cell Transplantation

Patients after hematopoietic stem cell transplantation (HSCT) are vulnerable to infections due to severe immunosuppression. Live-attenuated vaccines are contraindicated for two years after HSCT. The aim of this study was to assess the persistence of antibodies against measles, mumps, rubella and varicella in the first year after HSCT. Forty patients undergoing autologous (n = 12) or allogeneic (n = 28) HSCT were included in this study. Specific IgG antibodies to measles, mumps, rubella and varicella virus in serum samples were assessed by the LIAISON XL, a fully automated chemiluminescence analyzer, at seven different time points starting one week before HSCT and up to 12 months after HSCT. At baseline, before HSCT, most patients showed antibodies against measles (100%), mumps (80%), rubella (97.5%) and varicella (92.5%). Although titers declined over time, most patients retained antibodies against measles (92.5%), mumps (62.5%), rubella (87.5%) and varicella (85%) up to 12 months after HSCT. There was no significant difference between patients with and without GvHD concerning persistence of antibody titers. Significantly higher varicella titers were detected in autologous patients compared to patients with chronic GvHD. Considering that live-attenuated vaccines should not be administered during the first year after HSCT, the persistence of antibodies against these diseases is relevant.

Use of live viral vaccines after HCT: Still a lot to learn

Revaccination program after HCT is necessary due to the loss of lifelong immunity acquired by previous vaccination or infections. The program is complex and even in a favourable scenario, it takes more than 2 years to be completed. As the complexity of HCT increases (alternative donors, diversity of monoclonal antibodies), studies evaluating the response to vaccination in this population are welcome, especially those that evaluate live attenuated vaccines given their scarcity. Furthermore, measles, mumps, rubella and even yellow fever, and poliomyelitis outbreaks have perplexed infectious diseases clinicians and epidemiologists globally, most of them due to the decline in vaccination coverage rates in children and adults, because of the growth of antivaccine movements around the world. The study of Lin et al. adds important information about measles, mumps and rubella vaccination after HCT.

Humoral response and safety of the BNT162b2 and mRNA-1273 COVID-19 vaccines in allogeneic hematopoietic stem cell transplant recipients: An observational study

BACKGROUND

The effectiveness of mRNA COVID-19 vaccines and the optimal timing of vaccine administration in allogeneic hematopoietic stem cell transplantation (Allo-HSCT) recipients remains inadequately investigated. We examine the effectiveness and safety of mRNA COVID-19 vaccines in allo-HSCT recipients.

METHOD

This prospective observational study included 44 allo-HSCT recipients and 38 healthy volunteers. The proportion of subjects acquiring anti-S1 IgG antibodies were considered as the primary endpoint. The occurrence of adverse events after vaccination and objective deterioration of chronic graft-versus-host disease (GVHD) were defined as secondary endpoints. In addition, we compared the geometric mean titers (GMT) of anti-S1 antibody titers in subgroups based on time interval between transplantation and vaccination.

RESULTS

A humoral response to the vaccine was evident in 40 (91%) patients and all 38 healthy controls. The GMT of anti-S1 titers in patients and healthy controls were 277 (95% confidence interval [CI]: 120-643) BAU/mL and 532 (95% CI 400-708) BAU/mL, respectively. (p = 0.603). A short time interval between transplantation and vaccination (≤6 months) was associated with low anti-S1 IgG antibody titers. No serious adverse events and deterioration of chronic GVHD were observed. Only one case of new development of mild chronic GVHD was recorded.

CONCLUSION

Messenger RNA COVID-19 vaccines induce humoral responses in allo-HSCT recipients and can be administered safely.

Lessons learnt from influenza vaccination in immunocompromised children undergoing treatment for cancer

Influenza infection contributes substantially to global morbidity and mortality, with children undergoing treatment for cancer among the most vulnerable due to immunosuppression associated with disease and treatment. However, influenza remains one of the most common vaccine-preventable diseases. Despite international guidelines recommending inactivated influenza vaccination on the basis of data supporting efficacy and an excellent safety profile in this population, uptake has often been suboptimal due to persisting hesitancy among both patients and oncologists regarding the ability of the vaccine to mount a sufficient immune response, the optimal vaccine schedule and timing, and the best method to assess response in immunocompromised populations. In this Review, we discuss the evidence regarding influenza vaccination in children with cancer, factors that influence response, and highlight strategies to optimise vaccination. Host immune factors play a substantial role, thus principles learnt from influenza vaccination can be broadly applied for the use of inactivated vaccines in children with cancer.

SARS-CoV-2-Specific T Cell Responses in Immunocompromised Individuals with Cancer, HIV or Solid Organ Transplants

Adaptive immune responses play an important role in the clinical course of SARS-CoV-2 infection. While evaluations of the virus-specific defense often focus on the humoral response, cellular immunity is crucial for the successful control of infection, with the early development of cytotoxic T cells being linked to efficient viral clearance. Vaccination against SARS-CoV-2 induces both CD4+ and CD8+ T cell responses and permits protection from severe COVID-19, including infection with the currently circulating variants of concern. Nevertheless, in immunocompromised individuals, first data imply significantly impaired SARS-CoV-2-specific immune responses after both natural infection and vaccination. Hence, these high-risk groups require particular consideration, not only in routine clinical practice, but also in the development of future vaccination strategies. In order to assist physicians in the guidance of immunocompromised patients, concerning the management of infection or the benefit of (booster) vaccinations, this review aims to provide a concise overview of the current knowledge about SARS-CoV-2-specific cellular immune responses in the vulnerable cohorts of cancer patients, people living with HIV (PLWH), and solid organ transplant recipients (SOT). Recent findings regarding the virus-specific cellular immunity in these differently immunocompromised populations might influence clinical decision-making in the future.

[Vaccination before and after autologous hematopoietic cell transplantation for autoimmune diseases: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (MATHEC-SFGM-TC)]

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organized the 12th workshop on hematopoietic stem cell transplantation clinical practices harmonization procedures on September 2021 in Lille, France. In the absence of specific national or international recommendation, the French working group for autologous stem Cell transplantation in Auto-immune Diseases (MATHEC) proposed guidances for vaccinations of patients undergoing autologous hematopoietic stem cell transplantation for autoimmune disease, including in the context of SARS-Cov-2 pandemic.

Antibody Response against Vaccine Antigens in Children after TCRαβ-Depleted Haploidentical Stem Cell Transplantation: Is It Similar to That in Recipients with Fully Matched Donors?

Recipients of hematopoietic stem cell transplantation (HSCT) with HLA-mismatched donors are more immune suppressed than those with fully matched donors. The immunologic response to vaccines also may differ in HLA-mismatched haploidentical HSCT recipients. In this study, we aimed to evaluate the antibody response to vaccines in pediatric TCRαβ-depleted haploidentical HSCT recipients. This longitudinal study included a study group of 21 children who underwent haploidentical HSCT without CD19 depletion and with TCRαβ depletion and a control group of 38 children who underwent fully matched donor HSCT. Antibody levels were quantified by serologic tests before vaccination and after each dose against tetanus, diphtheria, pneumococcus, hepatitis B, hepatitis A, measles, rubella, mumps, and varicella. The median recipient age was significantly lower (P = .037) and the median donor age was significantly higher (P = .000) in the haploidentical group compared with the fully matched group. At the months 1, 3, 6, 9 and 12 post-transplantation, the median CD4, CD8, and CD19 cell counts and lymphocyte counts were similar in the haploidentical and fully matched groups. The median natural killer cell count was higher in the haploidentical group at the months 1, 3, and 6 post-transplantation (P = .001, .006, and .004, respectively). The median time to first vaccination was similar in the 2 groups (12.5 [range, 11 to 14] months for the haploidentical group and 11 [range, 9 to 13] months for the fully matched group; P = .441). Seroprotection rates were 100% in both groups after the second and third doses of diphtheria vaccine, the third dose of tetanus vaccine, the third dose of hepatitis B vaccine, the second and third doses of pneumococcal conjugate vaccines (PCV13), and pneumococcal polysaccharide vaccine (PSPV23), although lower after the initial doses and before vaccination. Seroprotection for hepatitis A, rubella, and varicella was >90% in the fully matched group and 100% for the haploidentical group after the second doses. Measles and mumps seroprotection rates were >80% in the haploidentical group and approximately 70% for the fully matched group after the second dose. Antibody response and seroprotection rates against vaccine antigens were similar in the haploidentical group and the fully matched when revaccination was started at 12 months post-transplantation. These findings support the idea that TCRαβ-depleted haploidentical HSCT recipients can be revaccinated according to the same vaccination schedule as fully matched HSCT recipients. Revaccination earlier after transplantation and vaccine responses for recipients of different types of HSCT should be evaluated in future studies.

Distinct Immune Reconstitution Profiles Captured by Immune Functional Assays at 6 Months Post Allogeneic Hematopoietic Stem Cell Transplantation

Immune reconstitution after allogeneic-hematopoietic-stem-cell transplantation (allo-HSCT) is a complex and individual process. In this cross-sectional study, whole-blood (WB) immune functional assay (IFA) was used to characterize immune function by assessing immune-related gene/pathway alterations. The usefulness of this tool in the context of infection, 6 months after transplantation, was evaluated. Sixty allo-HSCT recipients at 6 months after transplantation and 10 healthy volunteers (HV) were included. WB was stimulated in standardized TruCulture tubes using lipopolysaccharides and Staphylococcal enterotoxin B. Gene expression was quantified using a custom 144-gene panel using NanoString nCounter technology and analyzed using Ingenuity Pathway Analysis. The relationships between immune function and clinical characteristics, immune cell counts, and post-transplantation infections were assessed. Allo-HSCT recipients were able to activate similar networks of the innate and adaptive immune response compared to HV, with, nevertheless, a lower intensity. A reduced number and a lower expression of genes associated with immunoregulatory and inflammatory processes were observed in allo-HSCT recipients. The use of immunosuppressive treatments was associated with a protracted immune reconstitution revealed by transcriptomic immunoprofiling. No difference in immune cell counts was observed among patients receiving or not receiving immunosuppressive treatments using a large immunophenotyping panel. Moreover, the expression of a set of genes, including CCL3/CCL4, was significantly lower in patients with Herpesviridae reactivation (32%, 19/60), which once again was not identified using classical immune cell counts. Transcriptional IFA revealed the heterogeneity among allo-HSCT recipients with a reduced immune function, a result that could not be captured by circulating immune cell counts. This highlights the potential added value of this tool for the personalized care of immunocompromised patients.

T Cell and Cytokine Dynamics in the Blood of Patients after Hematopoietic Stem Cell Transplantation and Multipotent Mesenchymal Stromal Cell Administration

Multipotent mesenchymal stromal cells (MSCs) are currently under intensive investigation for the treatment and prevention of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), owing to their substantial immunomodulatory properties. The responses of recipients to MSC infusion following allo-HSCT are not yet well understood. T cells are central to the adaptive immune system, protecting the organism from infection and malignant cells. Memory T cells with different phenotypes, gene expression profiles, and functional properties are critical for immune processes regulation. The aim of this study was to study the dynamics of memory T cell subpopulations and cytokines in the blood of allo-HSCT recipients after MSC administration. In clinical trial NCT01941394, patients after allo-HSCT were randomized into 2 groups, one receiving standard GVHD prophylaxis and the other also receiving MSC infusion on the day of leukocyte recovery to 1000 cells/μL (engraftment, day E0). Blood samples of patients from both groups were analyzed on days E0, E+3, and E+30. T cell subpopulations were studied by flow cytometry, and cytokine concentrations were evaluated by the Bio-Plex Pro Human Cytokine Panel. Administration of MSCs to patients on day E0 did not affect the overall dynamics of restoration of absolute numbers and proportions of T and B lymphocytes after 3 and 30 days. At 3 days after MSC injection, only the numbers of CD8⁺ effector cells (CD8⁺_TE, CD8⁺_TM, and CD8⁺_EM) were found to increase significantly. A significant increase in the number of CD4⁺ cells after 30 days compared to day E0 was observed only in patients who received MSCs, indicating faster recovery of the CD4⁺ cell population following MSC injection. An increase in CD8⁺ cell number by day E+30 was significant regardless of MSC administration. To characterize the immune status of patients following allo-HSCT in more detail, changes in the cytokine concentration in the peripheral blood of patients on days E0, E+3, and E+30 after MSC administration were investigated. On day E+30, significant increases in the numbers of CD4⁺_CM and activated CD4⁺CD25⁺ cells were observed. The concentrations of proinflammatory and anti-inflammatory cytokines IL-6, IL-8, IL-17, TNF-α, and IFN-γ were increased significantly in patients injected with MSCs. Analysis of growth factor levels showed that in the group of patients who received MSCs, the concentrations of G-CSF, GM-CSF, PDGFbb, FGFb, and IL-5 increased by day E+30. Among the cytokines involved in regulation of the immune response, concentrations of IL-9, eotaxin, IP-10, MCP-1, and MIP-1a were increased after 30 days irrespective of MSC administration. The administration of MSCs exerts a positive effect on the restoration of T cell subpopulations and immune system recovery in patients after allo-HSCT.

Observational Study on Antibody Response to COVID-19 Vaccines in PAtients with Gastro-Entero-PanCreatic Cancers and NeuroendocrIne NeoplAsms on Systemic TreatmEnts (VACCINATE)

The coronavirus disease-19 (COVID-19) pandemic dramatically impacted oncological patients' care. Since the introduction of vaccines and the demonstration of their benefit on frail patients, COVID-19 vaccinations were indicated to also be beneficial to oncological population. However, data about the impact of anticancer-treatments and the timing between vaccinations and systemic therapy delivery were not available. We aimed to evaluate potential factors influencing the outcome of the COVID-19 vaccination in cancer patients. We prospectively collected data of patients undergoing the COVID-19 vaccination with gastro-entero-pancreatic and neuroendocrine neoplasms, treated at our institute, between 03/2021 and 12/2021. We enrolled 46 patients, 63.1% males; at the time of data collection, 86.9% had received two-doses of Pfizer-BioNTech and the rest had received the Moderna vaccine. All patients obtained a subsequent immune-response. Chemotherapy seems to determinate a significantly lower antibody response after vaccination compared to the other anti-cancer agents (p = 0.004). No significant effect on immune-response was reported for both vaccinations performed ≤7 vs. >7 days from the last systemic treatment (p = 0.77) and lymphocytes count (p = 0.11). The findings suggest that the optimal timing for COVID-19 vaccination and lymphocytes count are not the issue, but rather that the quality of the subset of lymphocytes before the vaccination determine the efficacy level of immune-response in this population.

Evaluation of Safety and Immunogenicity of a Recombinant Receptor-Binding Domain (RBD)-Tetanus Toxoid (TT) Conjugated SARS-CoV-2 Vaccine (PastoCovac) in Recipients of Autologous Hematopoietic Stem Cell Transplantation Compared to the Healthy Controls; A Prospective, Open-Label Clinical Trial

Background: The urgent need for prompt SARS-CoV-2 immunization of hematopoietic stem cell transplant (HSCT) recipients in an endemic area raises many challenges regarding selecting a vaccine platform appropriate for HSCT recipients being economical for widespread use in developing countries. Methods: The trial is a prospective, single-group, open-label study to investigate the safety and serologic response of two doses of the recombinant receptor-binding domain (RBD)-Tetanus Toxoid (TT) conjugated SARS-CoV-2 vaccine (PastoCovac) early after autologous (auto) HSCT. For this reason, a total of 38 patients who completed the two-dose SARS-CoV-2 RBD-based vaccine between three to nine months after auto-HSCT and had an available anti-spike serologic test at three predefined time points of baseline and after the first and second doses and 50 healthy control individuals were included in the analysis. The primary outcome was defined as an increase in IgG Immune status ratio (ISR) to the cut-off value for the positive result (≥1.1) in the semiquantitative test. Findings: The median time between auto-HSCT and vaccination was 127 days. No participant reported any significant adverse effects (Grade 3). Pain at the injection site was the most common adverse event. The ISR increased significantly (p < 0.001) during the three-time point sampling for both patients and healthy control groups. In patients, the mean ISR increased from 1.39 (95% CI: 1.13−1.65) at baseline to 2.48 (1.93−3.03) and 3.73 (3.13−4.38) following the first and second dosages, respectively. In multivariate analysis, the higher count of lymphocytes [OR: 8.57 (95% CI: 1.51−48.75); p = 0.02] and history of obtaining COVID-19 infection before transplantation [OR: 6.24 (95% CI: 1.17−33.15); p = 0.03] remained the predictors of the stronger immune response following two doses of the RBD-TT conjugated vaccine. Moreover, we found that the immunogenicity of the COVID-19 vaccine shortly after transplantation could be influenced by pre-transplant COVID-19 vaccination. Interpretation: The RBD-TT conjugated SARS-CoV-2 vaccine was safe, highly immunogenic, and affordable early after autologous transplants. Funding: This work was mainly financed by the Hematology-Oncology-Stem Cell Transplantation Research Center (HORCSCT) of Tehran University and the Pasteur Institute of Iran.