Clinical Effectiveness of Influenza Vaccination After Allogeneic Hematopoietic Stem Cell Transplantation: A Cross-sectional, Prospective, Observational Study

Are any specific respiratory viruses more severe than others in recipients of allogeneic stem cell transplantation? A focus on lower respiratory tract disease

In the general population, influenza virus, respiratory syncytial virus, and SARS-CoV-2 are considered the most severe community-acquired respiratory viruses (CARVs). However, allogeneic stem cell transplant (allo-SCT) recipients may also face severe courses from other CARVs. This retrospective study compared outcomes of various CARV lower respiratory tract diseases (LRTD) in 235 adult allo-SCT recipients, excluding co-infection episodes. We included 235 adults allo-SCT recipients experiencing 353 CARV LRTD consecutive episodes (130 rhinovirus, 63 respiratory syncytial virus, 43 influenza, 43 human parainfluenza virus, 23 human metapneumovirus, 19 Omicron SARS-CoV-2, 17 common coronavirus, 10 adenovirus and 5 human bocavirus) between December 2013 and June 2023. Day 100 overall survival ranged from 78% to 90% without significant differences among CARV types. Multivariable analysis of day 100 all-cause mortality identified corticosteroid use of >1 to <30 mg/d [Hazard ratio (HR) 2.45, p = 0.02) and ≥30 mg/d (HR 2.20, p = 0.015) along with absolute lymphocyte count <0.2 × 109/L (HR 5.82, p < 0.001) and number of CARV episodes as a continuous variable per one episode increase (HR 0.48, p = 0.001) as independent risk factors for all-cause mortality. Degree of immunosuppression, rather than intrinsic CARV virulence, has the most significant impact on mortality in allo-SCT recipients with CARV-LRTD.

Clinical manifestations, prognostic factors, and outcomes of adenovirus pneumonia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Severe pneumonia is one of the most important causes of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Adenovirus (ADV) is a significant cause of severe viral pneumonia after allo-HSCT, and we aimed to identify the clinical manifestations, prognostic factors, and outcomes of ADV pneumonia after allo-HSCT.

METHODS

Twenty-nine patients who underwent allo-HSCT at the Peking University Institute of Hematology and who experienced ADV pneumonia after allo-HSCT were enrolled in this study. The Kaplan-Meier method was used to estimate the probability of overall survival (OS). Potential prognostic factors for 100-day OS after ADV pneumonia were evaluated through univariate and multivariate Cox regression analyses.

RESULTS

The incidence rate of ADV pneumonia after allo-HSCT was approximately 0.71%. The median time from allo-HSCT to the occurrence of ADV pneumonia was 99 days (range 17-609 days). The most common clinical manifestations were fever (86.2%), cough (34.5%) and dyspnea (31.0%). The 100-day probabilities of ADV-related mortality and OS were 40.4% (95% CI 21.1%-59.7%) and 40.5% (95% CI 25.2%-64.9%), respectively. Patients with low-level ADV DNAemia had lower ADV-related mortality and better OS than did those with high-level (≥ 106 copies/ml in plasma) ADV DNAemia. According to the multivariate analysis, high-level ADV DNAemia was the only risk factor for intensive care unit admission, invasive mechanical ventilation, ADV-related mortality, and OS after ADV pneumonia.

CONCLUSIONS

We first reported the prognostic factors and confirmed the poor outcomes of patients with ADV pneumonia after allo-HSCT. Patients with high-level ADV DNAemia should receive immediate and intensive therapy.

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.

Outcome of Human Parainfluenza Virus infection in allogeneic stem cell transplantation recipients: possible impact of ribavirin therapy

BACKGROUND

This retrospective study focused on analyzing community-acquired respiratory virus (CARV) infections, in particular human parainfluenza virus (hPIV) after allogeneic stem cell transplant (allo-SCT) in adults recipients. It aimed to assess the impact of ribavirin treatment, clinical characteristics, and risk factors associated with lower respiratory tract disease (LRTD) progression and all-cause mortality.

PATIENTS AND METHODS

The study included 230 allo-SCT recipients diagnosed with hPIV between December 2013 and June 2023. Risk factors for the development of LRTD, disease severity, and mortality were analyzed. Ribavirin treatment was administered at physician discretion in 61 out of 230 cases (27%).

RESULTS

Risk factors for LRTD progression in multivariate analysis were corticosteroids > 30 mg/day (Odds ratio (OR) 3.5, 95% Confidence Interval (C.I.) 1.3-9.4, p = 0.013), fever at the time of hPIV detection (OR 3.89, 95% C.I. 1.84-8.2, p < 0.001), and absolute lymphocyte count (ALC) < 0.2 × 109/L (OR 4.1, 95% C.I. 1.42-11.9, p = 0.009). In addition, the study found that ribavirin therapy significantly reduced progression to LRTD [OR 0.19, 95% C.I. 0.05-0.75, p = 0.018]. Co-infections (OR 5.7, 95% C.I. 1.4-23.5, p = 0.015) and ALC < 0.2 × 109/L (OR 17.7, 95% C.I. 3.6-87.1, p < 0.001) were independently associated with higher day + 100 after hPIV detection all-cause mortality. There were no significant differences in all-cause mortality and infectious mortality at day + 100 between the treated and untreated groups.

CONCLUSION

ALC, corticosteroids, and fever increased the risk for progression to LRTD while ribavirin decreased the risk. However, mortality was associated with ALC and co-infections. This study supports further research of ribavirin therapy for hPIV in the allo-HSCT setting.

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.

Upper and/or Lower Respiratory Tract Infection Caused by Human Metapneumovirus After Allogeneic Hematopoietic Stem Cell Transplantation

BACKGROUND

Human metapneumovirus (hMPV) epidemiology, clinical characteristics and risk factors for poor outcome after allogeneic stem cell transplantation (allo-HCT) remain a poorly investigated area.

METHODS

This retrospective multicenter cohort study examined the epidemiology, clinical characteristics, and risk factors for poor outcomes associated with human metapneumovirus (hMPV) infections in recipients of allo-HCT.

RESULTS

We included 428 allo-HCT recipients who developed 438 hMPV infection episodes between January 2012 and January 2019. Most recipients were adults (93%). hMPV infections were diagnosed at a median of 373 days after allo-HCT. The infections were categorized as upper respiratory tract disease (URTD) or lower respiratory tract disease (LRTD), with 60% and 40% of cases, respectively. Patients with hMPV LRTD experienced the infection earlier in the transplant course and had higher rates of lymphopenia, neutropenia, corticosteroid use, and ribavirin therapy. Multivariate analysis identified lymphopenia and corticosteroid use (>30 mg/d) as independent risk factors for LRTD occurrence. The overall mortality at day 30 after hMPV detection was 2% for URTD, 12% for possible LRTD, and 21% for proven LRTD. Lymphopenia was the only independent risk factor associated with day 30 mortality in LRTD cases.

CONCLUSIONS

These findings highlight the significance of lymphopenia and corticosteroid use in the development and severity of hMPV infections after allo-HCT, with lymphopenia being a predictor of higher mortality in LRTD cases.

Risk factors for severity in seasonal respiratory viral infections and how they guide management in hematopoietic cell transplant recipients

PURPOSE OF REVIEW

Seasonal respiratory virus infections (RVIs) often progress to severe diseases in hematopoietic cell transplant (HCT) recipients. This review summarizes the current evidence on risk factors for the severity of RVIs in this high-risk population and provides clinical management.

RECENT FINDINGS

The likelihood of the respiratory viral disease progression depends on the immune status of the host and the type of virus. Conventional host factors, such as the immunodeficiency scoring index and the severe immunodeficiency criteria, have been utilized to estimate the risk of progression to severe disease, including mortality. Recent reports have suggested nonconventional risk factors, such as hyperglycemia, hypoalbuminemia, prior use of antibiotics with broad anaerobic activity, posttransplant cyclophosphamide, and pulmonary impairment after RVIs. Identifying novel and modifiable risk factors is important with the advances of novel therapeutic and preventive interventions for RVIs.

SUMMARY

Validation of recently identified risk factors for severe RVIs in HCT recipients is required. The development of innovative interventions along with appropriate risk stratification is critical to improve outcomes in this vulnerable population.

Lessons learned from COVID-19 pandemic: outcomes after SARS-CoV-2 infection in hematopoietic cell transplant and cell therapy recipients

We investigated the outcomes after Coronavirus disease 2019 (COVID) in hematopoietic cell transplant (HCT) or chimeric antigen receptor-T cell (CART) therapy recipients in a single-centre study including all (n = 261)HCT/CART recipients (allogeneic-HCT 49%, autologous-HCT 40%, CART 11%). The median age was 60 (22-80) years. COVID severity was mild (74%), moderate (11%), and severe/critical (16%) with a mortality rate of 7% and a median duration of infection of 5.7 weeks. Significant predictors of COVID severe disease or mortality included concurrent infection (HR 14.9, 95% CI 2.2-5.6) and immunosuppressive therapy (OR 4.8, 95% CI 1.2-3.4).HCT/CART recipients have a higher risk of mortality with COVID and warrant vigilant interventions.

Respiratory virus infections after allogeneic stem cell transplantation: Current understanding, knowledge gaps, and recent advances

Before the COVID-19 pandemic, common community-acquired seasonal respiratory viruses (CARVs) were a significant threat to the health and well-being of allogeneic hematopoietic cell transplant (allo-HCT) recipients, often resulting in severe illness and even death. The pandemic has further highlighted the significant risk that immunosuppressed patients, including allo-HCT recipients, face when infected with SARS-CoV-2. As preventive transmission measures are relaxed and CARVs circulate again among the community, including in allo-HSCT recipients, it is crucial to understand the current state of knowledge, gaps, and recent advances regarding CARV infection in allo-HCT recipients. Urgent research is needed to identify seasonal respiratory viruses as potential drivers for future pandemics.

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.

Risk factors for lower respiratory tract disease and outcomes in allogeneic hematopoietic stem cell transplantation recipients with influenza virus infection

INTRODUCTION

Influenza virus infection (IVI) is frequent in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, and reports from several countries indicate high morbidity and mortality from progression to lower respiratory tract disease (LRTD). However, there have been no reports on IVI clinical characteristics, treatment outcomes, and risk factor for progression to LRTD among allo-HSCT recipients in Japan.

METHODS

We retrospectively reviewed the medical charts of allo-HSCT recipients who developed IVI between 2012 and 2019.

RESULTS

Forty-eight cases of IVI following allo-HSCT were identified at our institution. The median age was 42 years, and median time from allo-HSCT to IVI was 25 months. Thirty-seven patients (77.1%) were administered neuraminidase inhibitors (NAIs) as antiviral therapy within 48 h of symptom onset (early therapy), whereas 11 (22.9%) received NAI over 48 h after onset (delayed therapy). Subsequently, 12 patients (25.0%) developed LRTD after IVI. Multivariate analysis identified older age (hazard ratio [HR], 7.65; 95% confidence interval [CI], 2.22-26.3) and bronchiolitis obliterans (HR, 5.74; 95% CI, 1.57-21.0) as independent risk factors for progression to LRTD. Moreover, land-mark analysis showed that early therapy prevented progression to LRTD (11.8% vs. 45.5%, P = 0.013). The IVI-related mortality rate was 2.1%.

CONCLUSIONS

Early NAI treatment is recommended for reducing the risk of LRTD progression due to IVI in allo-HSTC recipients, particularly for older patients and those with bronchiolitis obliterans.

Early Cellular and Humoral Responses Developed in Oncohematological Patients after Vaccination with One Dose against COVID-19

Individuals with oncohematological diseases (OHD) may develop an impaired immune response against vaccines due to the characteristics of the disease or to its treatment. Humoral response against SARS-CoV-2 has been described to be suboptimal in these patients, but the quality and efficiency of the cellular immune response has not been yet completely characterized. In this study, we analyzed the early humoral and cellular immune responses in individuals with different OHD after receiving one dose of an authorized vaccine against SARS-CoV-2. Humoral response, determined by antibodies titers and neutralizing capacity, was overall impaired in individuals with OHD, except for the cohort of chronic myeloid leukemia (CML), which showed higher levels of specific IgGs than healthy donors. Conversely, the specific direct cytotoxic cellular immunity response (DCC) against SARS-CoV-2, appeared to be enhanced, especially in individuals with CML and chronic lymphocytic leukemia (CLL). This increased cellular immune response, developed earlier than in healthy donors, showed a modest cytotoxic activity that was compensated by significantly increased numbers, likely due to the disease or its treatment. The analysis of the immune response through subsequent vaccine doses will help establish the real efficacy of COVID-19 vaccines in individuals with OHD.

SARS-CoV-2 vaccine response and rate of breakthrough infection in patients with hematological disorders

Background

The clinical efficacy of SARS-CoV-2 vaccines according to antibody response in immunosuppressed patients such as hematological patients has not yet been established.

Patients and methods

A prospective multicenter registry-based cohort study conducted from December 2020 to December 2021 by the Spanish transplant and cell therapy group was used to analyze the relationship of antibody response at 3–6 weeks after full vaccination (2 doses) with breakthrough SARS-CoV-2 infection in 1394 patients with hematological disorders.

Results

At a median follow-up of 165 days after complete immunization, 37 out of 1394 (2.6%) developed breakthrough SARS-CoV-2 infection at median of 77 days (range 7–195) after full vaccination. The incidence rate was 6.39 per 100 persons-year. Most patients were asymptomatic (19/37, 51.4%), whereas only 19% developed pneumonia. The mortality rate was 8%. Lack of detectable antibodies at 3–6 weeks after full vaccination was the only variable associated with breakthrough infection in multivariate logistic regression analysis (Odds Ratio 2.35, 95% confidence interval 1.2–4.6, p = 0.012). Median antibody titers were lower in cases than in non-cases [1.83 binding antibody units (BAU)/mL (range 0–4854.93) vs 730.81 BAU/mL (range 0–56,800), respectively (p = 0.007)]. We identified 250 BAU/mL as a cutoff above which incidence and severity of the infection were significantly lower.

Conclusions

Our study highlights the benefit of developing an antibody response in these highly immunosuppressed patients. Level of antibody titers at 3 to 6 weeks after 2-dose vaccination links with protection against both breakthrough infection and severe disease for non-Omicron SARS-CoV-2 variants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-022-01275-7.

SARS-CoV-2-reactive antibody detection after SARS-CoV-2 vaccination in hematopoietic stem cell transplant recipients: Prospective survey from the Spanish Hematopoietic Stem Cell Transplantation and Cell Therapy Group

This is a multicenter prospective observational study that included a large cohort (n = 397) of allogeneic (allo‐HSCT; (n = 311) and autologous (ASCT) hematopoietic stem cell transplant (n = 86) recipients who were monitored for antibody detection within 3–6 weeks after complete severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccination from February 1, 2021, to July 20, 2021. Most patients (n = 387, 97.4%) received mRNA‐based vaccines. Most of the recipients (93%) were vaccinated more than 1 year after transplant. Detectable SARS‐CoV‐2‐reactive antibodies were observed in 242 (78%) of allo‐HSCT and in 73 (85%) of ASCT recipients. Multivariate analysis in allo‐HSCT recipients identified lymphopenia < 1 × 10⁹/ml (odds ratio [OR] 0.33, 95% confidence interval [95% CI] 0.16–0.69, p = .003), active graft versus host disease (GvHD; OR 0.51, 95% CI 0.27–0.98, p = .04) and vaccination within the first year of transplant (OR 0.3, 95% CI 0.15–0.9, p = .04) associated with lower antibody detection whereas. In ASCT, non‐Hodgkin's lymphoma (NHL; OR 0.09, 95% CI 0.02–0.44, p = .003) and active corticosteroid therapy (OR 0.2, 95% CI 0.02–0.87, p = .03) were associated with lower detection rate. We report an encouraging rate of SARS‐CoV‐2‐reactive antibodies detection in these severe immunocompromised patients. Lymphopenia, GvHD, the timing of vaccine, and NHL and corticosteroids therapy should be considered in allo‐HSCT and ASCT, respectively, to identify candidates for SARS‐CoV‐2 antibodies monitoring.

Infectious complications and vaccines

Infections are a major cause of morbidity and can result in mortality in long-term survivors after allogeneic hematopoietic cell transplantation. Chronic graft-versus-host disease and delayed immune reconstitution are recognized risk factors. Different strategies must be utilized depending on the individual patient's situation but include prolonged antimicrobial prophylaxis and vaccination. Some important infections due to pathogens preventable by vaccination are pneumococci, influenza, varicella-zoster virus, and SARS-CoV-2. Despite the fact that such recommendations have been in place for decades, implementation of these recommendations has been reported to be poor.

Spanish Society of Hematology and Hemotherapy expert consensus opinion for SARS-CoV-2 vaccination in onco-hematological patients

In the midst of the COVID-19 pandemic, different vaccines in front of SARS-CoV-2 have been approved and administered in different vulnerable populations. As patients with cancer were excluded from pivotal trials of vaccination, little is known on their immunogenic response to these vaccines, particularly in patients with severely impaired immune system. In response to that uncertainty, the Spanish Society of Hematology and Hemotherapy launched an initiative aimed to provide recommendations for vaccination of the main hematological conditions. This document is based on the available information on COVID-19 outcomes, prior knowledge on vaccination in hematological patients, recent published data on serological response in oncohematological patients and expert opinions. New information about SARS-CoV-2 vaccination will be gathered in the near future, providing new scientific grounds to delineate the most adequate management of vaccination in patients with hematological diseases. The current limited data on SARS-CoV-2 vaccines in hematological patients represents a major limitation of this expert consensus opinion. In fact, the speed in which this field evolves may reduce their validity in the near future.

Impact of SARS-CoV-2 in Hematopoietic Stem Cell Transplantation and Chimeric Antigen Receptor T Cell Therapy Recipients

Coronavirus disease 2019 (COVID-19), a respiratory illness caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic in March 2020, and has caused more than 600,000 deaths in the United States at the time of this report. Hematopoietic stem cell transplantation (HCT) or chimeric antigen receptor T cell (CAR-T) therapy recipients have a higher risk of mortality with COVID-19 owing to profound immune dysregulation. In this study, we investigated the impact of SARS-CoV-2 in HCT/CAR-T therapy recipients. This single-center prospective study included all (n = 58) adult HCT/CAR-T recipients who were diagnosed with COVID-19 at the University of Kansas Medical Center between March 2020 and May 2021. Baseline and disease-related characteristics were ascertained from medical records. Data were analyzed using SPSS version 21 (IBM, Armonk, NY). Bivariate analyses, using the chi-square and t-test, and logistic regression analyses were conducted. The study included 58 HCT/CAR-T patients who acquired SARS-CoV-2 infection, including recipients of allogeneic HCT (n = 32), autologous HCT (n = 23), and CAR-T therapy (n = 3). The median patient age was 58 years (range, 24 to 77 years), and 64% were males. The median time from HCT/CAR-T therapy to SARS-CoV-2 infection was 17.7 months (range, 0.2 to 201.9 months), and 22% of the patients acquired SARS-CoV-2 within the first 100 days post-HCT/CAR-T therapy. The primary hematologic disorders were plasma cell (36%), myeloid (38%), and lymphoid (26%) malignancies. Myeloablative conditioning was performed in 62% of patients. Donors were autologous (45%), matched sibling (15%), matched unrelated (21%), and haploidentical (19%). Prior history of grade II-IV acute graft-versus-host disease (GVHD), active GVHD, and current immunosuppressive therapy (IST) was noted in 22%, 31%, and 36% of patients, respectively. Concurrent infections were observed in 19%. Lymphopenia (P = .049) and high serum ferritin concentration (P = .020) were associated with mortality. COVID-19 severity was mild in 50% of the patients, moderate in 22%, and severe in 28%. Clinical findings included pneumonia or abnormal chest imaging (in 50%), hypoxia (28%), intensive care unit admission (19%), and mechanical ventilation (10%). Therapies included remdesivir (in 41%), convalescent plasma (35%), dexamethasone (22%), monoclonal antibodies (19%), and tocilizumab (3%). The median duration of viral shedding (positive SARS-CoV-2 PCR) was 7.7 weeks (range, 2 to 18.7 weeks), and 2 patients had a persistent infection for >5 months post-CAR-T therapy. After a median follow-up of 6.1 months (range, 0.5-13.6 months), the mortality rate was 16% in all patients and 28% in allogeneic HCT recipients. Among 9 patients who died, the median survival after SARS-CoV-2 infection was 23 days (range, 14 to 140 days). In survivors with moderate-severe COVID-19, the median time to recovery was 4.2 weeks (range, 1.1 to 24.7 weeks). Among allogeneic HCT recipients, 5 (16%) developed subsequent pulmonary chronic GVHD necessitating systemic steroids and additional IST. Significant predictors of COVID-19 severity included allogeneic HCT (odds ratio [OR], 3.6, 95% confidence interval [CI], 1.2 to 10.8; P = .020), history of grade II-IV acute GVHD (OR, 4.6; 95% CI, 1.10 to 18.86; P = .036) and concurrent IST (OR, 5.9; 95% CI, 1.8 to 19.8; P = .004). HCT and CAR-T cell therapy recipients are at an increased risk of moderate-severe COVID-19 pneumonia and higher mortality with SARS-CoV-2 infection. Our findings confirm the need for continuing vigilance with social distancing and masks, vaccination prioritization, close monitoring, and aggressive treatment of HCT/CAR-T therapy recipients.

Preparing for the 2020-2021 influenza season

The COVID-19 pandemic has altered health seeking behaviors and has increased attention to non-pharmaceutical interventions that reduce the risk of transmission of respiratory viruses including SARS-CoV-2 and influenza. While the potential impact of the COVID-19 pandemic on influenza is not fully known, in the Southern hemisphere influenza infection rates appear to be very low. Influenza vaccine efficacy for 2019-2020 season was comparable to prior season and influenza vaccine recommendations for pediatric immunizations remain similar to prior years. Influenza treatments continue to include neuraminidase inhibitors as well as baloxavir for treatment and in some instances prophylaxis.

Seasonal Human Coronavirus Respiratory Tract Infection in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

Background

Little is known about characteristics of seasonal human coronavirus (HCoV) (NL63, 229E, OC43 and HKU1) after allogeneic stem cell transplantation (allo-HCT).

Patients and methods

this is a collaborative Spanish and European bone marrow transplantation groups retrospective multicentre study, which included allo-HCT recipients (adults and children) with upper and/or lower respiratory tract disease (U/LRTD) caused by seasonal HCoV diagnosed through multiplex PCR assays from January 2012 to January 2019.

Results

We included 402 allo-HCT recipients who developed 449 HCoV U/LRTD episodes. Median age of recipients was 46 years (range 0.3-73.8 years). HCoV episodes were diagnosed at a median of 222 days after transplantation. The most common HCoV subtype was OC43 (n=170, 38%). LRTD involvement occurred in 121 episodes (27%). HCoV infection frequently required hospitalization (18%), oxygen administration (13%) and intensive care unit (ICU) admission (3%). Three-month overall mortality after HCoV detection was 7% in the whole cohort and 16% in those with LRTD. We identified 3 conditions associated with higher mortality in recipients with LRTD: absolute lymphocyte count <0.1 x10 ⁹/mL [hazard ratio (HR), 10.8], corticosteroid (HR 4.68) and ICU admission (HR 8.22) (p<0.01).

Conclusions

Seasonal HCoV after allo-HCT may involve the LRTD in many instances, leading to a significant morbidity.

Influenza vaccination in immunocompromised populations: Strategies to improve immunogenicity

Immunocompromised individuals are at high risk of severe illness and complications from influenza infection. For this reason, immunization using inactivated influenza vaccines is recommended for transplant patients, individuals receiving immunosuppressant treatments, and other persons with immunodeficiency. However, these immunocompromised populations are more likely to have lower and non-protective responses to annual vaccination with a standard influenza vaccine. Here, we review strategies aimed to improve the immunogenicity of influenza vaccines in immunocompromised populations. The different strategies employed have included adjuvanted vaccines, high-dose vaccines, booster doses, intradermal vaccination, and temporary discontinuation of immunosuppressant treatment regimens. High-dose trivalent, inactivated, split-virus influenza vaccine (IIV3-HD) is so far one of the leading strategies for improving vaccine responses in HIV patients, transplant patients, and persons receiving immunosuppressant therapies for inflammatory diseases. Several studies in these populations have shown stronger humoral responses with IIV3-HD than existing standard-dose trivalent vaccine, and comparable safety. Accordingly, some scientific societies have stated that high-dose influenza vaccine could be a preferred option for immunocompromised patients. However, larger randomized controlled studies are needed to validate relative immunogenicity and safety of IIV3-HD and other enhanced vaccines and vaccination strategies in immunocompromised individuals.

Common seasonal respiratory virus infections in allogeneic stem cell transplant recipients during the SARS-COV-2 pandemic

The SARS-COV-2 pandemic has led to strict and generalized transmission prevention measures that may have changed the epidemiological landscape of common seasonal respiratory virus (CSRV). Through a prospective CSRV survey program conducted from 2016 onwards in allogeneic stem cell transplant (allo-HSCT) recipients with respiratory symptoms, we aimed to analyze and compare the epidemiology and characteristics of CSRV over three consecutive periods [from February 1 to September 30 of 2018 (P1), 2019 (P2), and 2020 (P3)]. CSRV screening was performed through multiplex PCR assays during the study period. We identified 188 consecutive allo-HSCT recipients with 406 episodes screened for CSRV during the study period, of which 147 developed 300 CSRV. In P1 and P2 we diagnosed 115 (38.3%) and 145 (48.3%) CSRV episodes, respectively, whereas in P3 only 40 (13.3%) episodes were detected (p < 0.001). During P3, we observed a reduction of 80.2% in Ev/Rh, 93.3% in RSV, 80% in hIV, 96.3% HPIV, 68.4% in hMPV, 77.7% in ADV, 100% in HBoV, and 53.6% in HCoV as compared to P1 and P2. Consequently, we also observed a decline in absolute numbers of lower respiratory tract disease (68.1%), co-infections (91.7%), and hospitalizations (72.6%) during P3. We diagnosed SARS-COV-2 in nine allo-HSCT recipients, representing 23% of all CSRV detections in that period. In conclusion, we provide evidence of a significant drop in CSRV circulation during the SARS-COV-2 pandemic in our allo-HSCT recipients, indicating that prevention measures in the general population are highly effective in reducing CSRV prevalence and its complications in immunocompromised patients.

A randomised trial of two 2-dose influenza vaccination strategies for patients following autologous haematopoietic stem cell transplantation

BACKGROUND

Seroprotection and seroconversion rates are not well understood for 2-dose inactivated influenza vaccination (IIV) schedules in autologous haematopoietic stem cell transplantation (autoHCT) patients.

MATERIALS/METHODS

A randomised single-blind controlled trial of IIV in autoHCT patients in their first year post-transplant was conducted. Patients were randomised 1:1 to high dose (HD) IIV followed by standard dose (SD) vaccine (HD-SD arm) or two SD vaccines (SD-SD arm), 4 weeks apart. Haemagglutination inhibition (HI) assay for IIV strains was performed at baseline, 1, 2 and 6 months post-first dose. Evaluable primary outcomes were seroprotection (HI titre ≥40) and seroconversion (4-fold titre rise) rates and secondary outcomes: geometric mean titres (GMT), GMT ratios (GMR), adverse events, influenza-like-illness (ILI) and laboratory-confirmed influenza (LCI) rates and factors associated with seroconversion.

RESULTS

Sixty-eight patients were enrolled (34 per arm) with median age of 61.5 years, majority male (68%) with myeloma (68%). Median time from autoHCT to vaccination was 2.3 months. For HD-SD and SD-SD arms, percentage of patients achieving seroprotection was 75.8% and 79.4% for H1N1, 84.9% and 88.2% for H3N2 (all p>0.05) and 78.8% and 97.1% for influenza-B/Yamagata (p=0.03), respectively. Seroconversion rates, GMT and GMR, number of ILI or LCIs were not significantly different between arms. Adverse event rates were similar. Receipt of concurrent cancer therapy was independently associated with higher odds of seroconversion (OR 4.3, 95% CI 1.2-14.9, p=0.02).

CONCLUSIONS

High seroprotection and seroconversion rates against all influenza strains can be achieved with vaccination as early as 2 months post-autoHCT with either two-dose vaccine schedules.

Recommendations for screening, monitoring, prevention, and prophylaxis of infections in adult and pediatric patients receiving CAR T-cell therapy: a position paper

Chimeric antigen receptor (CAR) T-cell therapy is one of the most promising emerging treatments for B-cell malignancies. Recently, two CAR T-cell products (axicabtagene ciloleucel and tisagenlecleucel) have been approved for patients with aggressive B-cell lymphoma and acute lymphoblastic leukemia; many other CAR-T constructs are in research for both hematological and non-hematological diseases. Most of the patients receiving CAR-T therapy will develop fever at some point after infusion, mainly due to cytokine release syndrome (CRS). The onset of CRS is often indistinguishable from an infection, which makes management of these patients challenging. In addition to the lymphodepleting chemotherapy and CAR T cells, the treatment of complications with corticosteroids and/or tocilizumab increases the risk of infection in these patients. Data regarding incidence, risk factors and prevention of infections in patients receiving CAR-T cell therapy are scarce. To assist in patient care, a multidisciplinary team from hospitals designated by the Spanish Ministry of Health to perform CAR-T therapy prepared these recommendations. We reviewed the literature on the incidence, risk factors, and management of infections in adult and pediatric patients receiving CAR-T cell treatment. Recommendations cover different areas: monitoring and treatment of hypogammaglobulinemia, prevention, prophylaxis, and management of bacterial, viral, and fungal infections as well as vaccination prior and after CAR-T cell therapy.

Immunization Strategies to Span the Spectrum of Immunocompromised Adults

The Advisory Committee on Immunization Practices to the US Centers for Disease Control and Prevention provides annual recommendations for routine adult immunizations. Many recommendations consider patient factors such as age, medical conditions, and medications that increase an individual's risk for infection with a vaccine-preventable disease. These factors, particularly those that lead to immunocompromise, may also alter the risk-benefit ratio for live vaccines, and/or lead to decreased vaccine immunogenicity and effectiveness. The provider may need to consider alternative vaccination strategies, including higher antigen dose vaccines, adjuvanted vaccines, avoidance of live vaccines, and careful timing of vaccination to optimize safety and effectiveness in immunocompromised populations. This thematic review discusses general principles regarding immunization of adults across the spectrum of immunocompromise, examines current guidelines and studies that support them, and outlines future research needs.

Community acquired respiratory virus infections in adult patients undergoing umbilical cord blood transplantation

Characteristics and risk factors (RFs) of community-acquired respiratory virus (CARV) infections after umbilical cord blood transplantation (UCBT) are lacking. We retrospectively analyzed CARV infections in 216 single-unit myeloablative UCBT recipients. One-hundred and fourteen episodes of CARV infections were diagnosed in 62 (29%) patients. Upper respiratory tract disease (URTD) occurred in 61 (54%) whereas lower respiratory tract disease (LRTD) in 53 (46%). The 5-year cumulative incidence of CARV infection was 29%. RFs for developing CARV infections were: prednisone-based graft-versus-host disease (GVHD) prophylaxis and grade II–IV acute GVHD. RFs analysis of CARV progression to LRTD identified 2007–2009 period and absolute lymphocyte count (ALC) < 0.5 × 10⁹/L. ALC < 0.5 × 10⁹/L had a negative impact on day 60 mortality in both overall CARV and those with LRTD, whereas proven LRTD was associated with higher day 60 mortality. CARV infections had a negative effect on non-relapse mortality. Overall survival at day 60 after CARV detection was significantly lower in recipients with LRTD compared with URTD (74% vs. 93%, respectively). In conclusion, CARV infections after UCBT are frequent and may have a negative effect in the outcomes, in particular in the context of lymphocytopenia.

The clinical benefit of instituting a prospective clinical community-acquired respiratory virus surveillance program in allogeneic hematopoietic stem cell transplantation

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Rapid detection methods used as first diagnostic test for CARVs may delayed the start of antiviral therapy in a significant number of influenza and RSV cases.

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Syndromic multiplex RT-PCR-based prospective clinical CARV survey in allo-HCT recipients translates into a lower mortality rate as compared to standard clinical practice based on RSV and influenza virus rapid detection test.

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We found that donor/recipient HLA mismatch, CARV LRTD and high-risk ISI were also associated with higher mortality.

Background

There is a lack of studies comparing clinical outcomes among retrospective versus prospective cohorts of allogeneic stem cell transplant (allo-HCT) recipients with community acquired respiratory virus (CARV) infections.

Methods

We compare outcomes in two consecutive cohorts of allo-HCT recipients with CARV infections. The retrospective cohort included 63 allo-HCT recipients with 108 CARV infections from January 2013 to April 2016 who were screened and managed following standard clinical practice based on influenza and respiratory syncytial virus rapid antigen detection methods. The prospective cohort was comprised of 144 consecutive recipients with 297 CARV episodes included in a prospective interventional clinical surveillance program (ProClinCarvSur-P) based on syndromic multiplex PCR as first-line test from May 2016 to December 2018 at a single transplant center.

Results

CARV infections in the retrospective cohort showed more severe clinical features at the time of diagnosis compared to the prospective cohort (fever 83% vs. 57%, hospital admission 69% vs. 28% and lower respiratory tract 58% vs. 31%, respectively, p ≤ 0.002 for all comparisons). Antiviral therapy was more commonly prescribed in the prospective cohort (69 vs. 43 treated CARV episodes), particularly at the upper respiratory tract disease stage (34 vs. 12 treated CARV episodes). Three-month all-cause mortality was significantly higher in the retrospective cohort (n = 23, 37% vs. n = 10, 7%, p < 0.0001). Multivariate logistic regression analysis showed that recipients included in ProClinCarvSur-P had lower mortality rate [odds ratio 0.31, 95% confidence interval 0.12–0.7, p = 0.01].

Conclusion

This study report on outcome differences when reporting retrospective vs. prospective CARV infections after allo-HCT. Recipients included in a ProClinCarvSur-P had lower mortality.

Vaccination of the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient

Patients with hematologic malignancy or those who undergo hematopoietic stem cell transplantation experience variable degrees of immunosuppression, dependent on underlying disease, therapy received, time since transplant, and complications, such as graft-versus-host disease. Vaccination is an important strategy to mitigate onset and severity of certain vaccine-preventable illnesses, such as influenza, pneumococcal disease, or varicella zoster infection, among others. This article highlights vaccines that should and should not be used in this patient population and includes general guidelines for timing of vaccination administration and special considerations in the context of newer therapies, recent vaccine developments, travel, and considerations for household contacts.

The effect of timing on community acquired respiratory virus infection mortality during the first year after allogeneic hematopoietic stem cell transplantation: a prospective epidemiological survey

The effect of timing of community acquired respiratory virus (CARV) infection after allogeneic hematopoietic stem cell transplant (allo-HCT) is an as yet unsettled issue. We evaluate this issue by including all consecutive allo-HCT recipients with molecularly-documented CARV infection during the first year after transplant. The study cohort was drawn from a prospective longitudinal survey of CARV in allo-HCT recipient having respiratory symptoms conducted from December 2013 to December 2018 at two Spanish transplant centers. Respiratory viruses in upper and/or lower respiratory specimens were tested using multiplex PCR panel assays. The study cohort comprised 233 allo-HCT recipients with 376 CARV infection episodes diagnosed during the first year after allo-HCT. Overall, 60% of CARV episodes occurred within the first 6 months (227 out of 376). Thirty patients (13%) had died at 3 months after CARV detection, of which 25 (83%) were recipients developing CARV within the first 6 months after transplant. Multivariate analysis identified four risk factors for mortality: ATG used as part of conditioning regimen [odds ratio (OR) 2.8, 95% confidence interval (C.I.) 1.21-6.4, p = 0.01], CARV lower respiratory tract disease (OR 3.4, 95% C.I. 1.4-8.4, p = 0.007), CARV infection within the first 6 months of transplant (OR 3.04, 95% C.I. 1.1-8.7, p = 0.03), and absolute lymphocyte count <0.2 × 109/L (OR 2.4, 95% C.I. 1-5.3, p = 0.04). Developing CARV infection within the first 6 months was associated with higher mortality. Our data supports that the timing of CARV development after allo-HCT could be of major interest.

Community-Acquired Respiratory Viruses in Transplant Patients: Diversity, Impact, Unmet Clinical Needs

Patients undergoing solid-organ transplantation (SOT) or allogeneic hematopoietic cell transplantation (HCT) are at increased risk for infectious complications. Community-acquired respiratory viruses (CARVs) pose a particular challenge due to the frequent exposure pre-, peri-, and posttransplantation. Although influenza A and B viruses have a top priority regarding prevention and treatment, recent molecular diagnostic tests detecting an array of other CARVs in real time have dramatically expanded our knowledge about the epidemiology, diversity, and impact of CARV infections in the general population and in allogeneic HCT and SOT patients. These data have demonstrated that non-influenza CARVs independently contribute to morbidity and mortality of transplant patients. However, effective vaccination and antiviral treatment is only emerging for non-influenza CARVs, placing emphasis on infection control and supportive measures. Here, we review the current knowledge about CARVs in SOT and allogeneic HCT patients to better define the magnitude of this unmet clinical need and to discuss some of the lessons learned from human influenza virus, respiratory syncytial virus, parainfluenzavirus, rhinovirus, coronavirus, adenovirus, and bocavirus regarding diagnosis, prevention, and treatment.

Incidence, risk factors, and outcome of pulmonary invasive fungal disease after respiratory virus infection in allogeneic hematopoietic stem cell transplantation recipients

BACKGROUND

There is growing evidence that community-acquired respiratory virus (CARV) increases the risk of pulmonary invasive fungal disease (IFD) in the allogeneic hematopoietic stem cell transplantation (allo-HSCT) setting. To date, there is a lack of knowledge regarding the risk factors (RFs), as well as the most critical period for subsequent onset of IFD after CARV infections in allo-HSCT recipients.

METHODS

In this prospective longitudinal observational CARV survey, we analyzed the effect of CARV on subsequent IFD development in 287 adult allo-HSCT recipients diagnosed with 597 CARV episodes from December 2013 to December 2018. Multiplex PCR panel assays were used to test CARVs in respiratory specimens.

FINDINGS

Twenty-nine out of 287 allo-HSCT recipients (10%) developed IFD after a CARV episode. The median time of IFD onset was 21 days (range, 0-158 days) from day of the first CARV detection. Generalized estimating equation model identified 4 risk factors for IFD: ATG-based conditioning regimen [odds ratio (OR) 2.34, 95% confidence interval (CI) 1.05-5.2, P = .038], CARV lower respiratory tract disease (OR 10.6, 95% CI 3.7-30.8, P < .0001), CARV infection during the first year after transplant (OR 5.34, 95% CI 1.3-21.8, P = .014), and corticosteroids during CARV (OR 2.6, 95% CI 1.1-6.3, P = .03).

CONCLUSION

Allo-HSCT recipients conditioned with ATG and under corticosteroid therapy at the time of CARV LRTD during the first year after transplant may require close monitoring for subsequent IFD.

Respiratory Virus Infections of the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient

Respiratory virus infections in hematologic stem cell transplant recipients and patients with hematologic malignancies are increasingly recognized as a cause of significant morbidity and mortality. The often overlapping clinical presentation makes molecular diagnostic strategies imperative for rapid diagnosis and to inform understanding of the changing epidemiology of each of the respiratory viruses. Most respiratory virus infections are managed with supportive therapy, although there is effective antiviral therapy for influenza. The primary focus should remain on primary prevention infection control procedures and isolation precautions, avoidance of ill contacts, and vaccination for influenza.