Differential loss of humoral immunity against measles, mumps, rubella and varicella-zoster virus in children treated for cancer

A neutralizing antibody prevents postfusion transition of measles virus fusion protein

Measles virus (MeV) presents a public health threat that is escalating as vaccine coverage in the general population declines and as populations of immunocompromised individuals, who cannot be vaccinated, increase. There are no approved therapeutics for MeV. Neutralizing antibodies targeting viral fusion are one potential therapeutic approach but have not yet been structurally characterized or advanced to clinical use. We present cryo-electron microscopy (cryo-EM) structures of prefusion F alone [2.1-angstrom (Å) resolution], F complexed with a fusion-inhibitory peptide (2.3-Å resolution), F complexed with the neutralizing and protective monoclonal antibody (mAb) 77 (2.6-Å resolution), and an additional structure of postfusion F (2.7-Å resolution). In vitro assays and examination of additional EM classes show that mAb 77 binds prefusion F, arrests F in an intermediate state, and prevents transition to the postfusion conformation. These structures shed light on antibody-mediated neutralization that involves arrest of fusion proteins in an intermediate state.

Seroprevalence of Measles (Rubeola) Antibodies in Childhood Cancer Survivors

Background: Measles is reemerging as a public health threat, raising important questions about disease vulnerability among childhood cancer survivors. This secondary analysis assessed the seroprevalence of anti-measles immunoglobulin G (IgG) antibodies as a marker of immune status in survivors of childhood cancer and associated demographic/treatment variables. Method: Participants were childhood cancer survivors who were free of active disease, having routine blood studies drawn, and could provide documentation of having received two doses of measles, mumps, and rubella vaccine before their cancer diagnosis. Patient record review documented demographic and treatment variables. Antimeasles (rubeola) IgG antibody seroprevalence was assessed by enzyme immunoassay for vaccine-specific antibodies. Results: Of 270 survivors evaluated, 110 (42%) were female, 196 (75%) were White, and 159 (61%) were leukemia/lymphoma survivors. Of these 262, 110 (42%) had negative measles seroprevalence, suggesting loss of immunity. Conclusion: Measles antibody surveillance and the need for reimmunization for survivors of childhood cancer survivors outside the transplant setting remains controversial. Our analysis indicates that a substantial proportion of survivors lose vaccine-related immunity to measles. Pediatric oncology nurses play important roles in educating cancer survivors regarding their risk of measles infection, evaluating the need for reimmunization, correcting misinformation about vaccine safety and effectiveness, and working to optimize community herd-based immunity.

Adequate immune responses to vaccines after chemotherapy for leukaemia diagnosed in childhood

AIM

The survival rate after treatment for childhood leukaemia has greatly improved, but could result in protracted immune deficiency. This study examined the immune status of children after chemotherapy and evaluated their responses to immunisation.

METHODS

Subjects who had completed their treatment for acute lymphoblastic leukaemia at The Children's Hospital Reykjavík, Iceland, during 2011-2020 had blood drawn and were then immunised for influenza in October 2021. Blood was drawn again 4 weeks later and their humoral and cellular responses were measured with a haemagglutination inhibition assay and lymphocyte stimulation test. Antibodies to other immunisations were also evaluated.

RESULTS

We studied 18 patients (10 male) who had completed their treatment at 3.7-20.3 years of age (mean 9.1), 11-84 months (mean 36.9) before enrolment. Conventional immunological evaluation did not reveal notable abnormalities. The responses to several childhood vaccinations, including the pneumococcal conjugate vaccination, were adequate in most patients. Humoral responses to the influenza vaccine confirmed adequate reactions in all but one patient. Considerable variations were observed in the lymphocyte stimulations tests.

CONCLUSION

Most patients reacted adequately to immunisation, especially against annual influenza and Streptococcus pneumoniae, reiterating the usefulness of vaccinations. The most appropriate timing for vaccination after treatment still needs to be determined.

Vaccine Immunity in Children After Hematologic Cancer Treatment: A Retrospective Single-center Study

BACKGROUND

Children lose their vaccine-induced protection and are particularly vulnerable to vaccine-preventable diseases after chemotherapy. However, revaccination guidelines are heterogeneous, and there is often a lack of revaccination post-treatment.

AIMS

We conducted a retrospective study of children with hematologic cancer to evaluate vaccine immunity before and after the end of treatment and to determine whether the current institutional revaccination program based on vaccine serology results was followed and effective.

MATERIALS AND METHODS

Data of all children treated by chemotherapy between April 2015 and July 2021 were extracted from hospital medical records for analysis. Serum antibody levels and time of vaccination were evaluated for diphtheria, tetanus, Streptococcus pneumoniae , Haemophilus influenzae type b (Hib), measles, varicella, and hepatitis B.

RESULTS

We included 31 patients (median age, 9 years). At cancer diagnosis, 90% of children were protected against tetanus, diphtheria, and measles; 65% to 67% were protected against pneumococcus and varicella; and 25% against hepatitis B. At the end of chemotherapy, 67% to 71% of patients were protected against tetanus, varicella, and measles; 40% remained protected against hepatitis B; and 27% to 33% against pneumococcus and diphtheria. Patients were revaccinated at various times after the end of treatment but not systematically. During the first-year post-treatment, 20% to 25% of children remained unprotected against pneumococcus, measles, and hepatitis B, one third against diphtheria, but all were protected against tetanus and varicella.

CONCLUSIONS

An effective individualized vaccination program post-cancer based on serology results should be accompanied by an appropriate serology tracking method and follow-up to assess if booster doses are necessary. Our study supports vaccinating all children with a dose of the 13-valent pneumococcal conjugate at cancer diagnosis and at 3 months post-treatment with the combined diphtheria-tetanus-acellular pertussis/poliomyelitis vaccine/hepatitis B virus plus or minus Hib and 13-valent pneumococcal conjugate and meningococcal vaccine, including measles/mumps/rubella-varicella zoster virus vaccine if good immune reconstitution is present.

Loss of humeral immunity in childhood cancer survivors not having undergone hematopoietic stem cell transplantation

BACKGROUND

Data are limited and conflicting regarding loss of immunity in childhood cancer survivors who did not undergo hematopoietic stem cell transplantation. The purpose of this retrospective, single center study is to provide further data to help build unifying revaccination guidelines post-chemotherapy in childhood cancer survivors not having undergone hematopoietic stem cell transplantation.

METHODS

This retrospective study included 28 childhood cancer survivors, 14 males and 14 females, whose treatment consisted of at least 3 months of chemotherapy and with confirmation of completing their primary vaccination series prior to therapy. The rate of vaccine titer seropositivity for cancer survivors was compared with the expected general population, based on long-term studies of anti-body persistence.

RESULTS

Decreased seropositivity for measles, mumps, rubella, varicella, tetanus, and hepatitis B was found in patients across all categories of malignancy compared with the general population. However, tetanus was not statistically significant. Results were more pronounced for those with hematological malignancies.

CONCLUSIONS

This study indicates that pediatric cancer survivors, especially those with hematological malignancies, may have greater loss of protective antibodies from primary vaccinations. Further studies are needed to provide guidelines for revaccination of both hematologic malignancies and solid tumor childhood cancer survivors who did not undergo hematopoietic stem cell transplantation.

Measles, mumps, and rubella revaccination in children after completion of chemotherapy and hematopoietic stem cell transplantation: a single-center prospective efficacy and safety analysis

BACKGROUND

Chemotherapy and hematopoietic stem cell transplantation (HSCT) can damage the immune system, and may result in a loss of protection from infectious diseases. This study aimed to evaluate the impact of these treatments on the decrease in antibody titers of the measles, mumps, and rubella (MMR) vaccine and seroconversion post-revaccination of MMR.

METHODS

After completion of treatment for primary diseases, participants received an MMR revaccination. Antibody titers for MMR before revaccination were analyzed for all 110 children. After revaccination, 68 participants received a follow-up evaluation of  antibody titer and adverse reaction.

RESULTS

Multivariable analysis showed that therapeutic schedules were the only factor correlated with lack of antibody titers for measles after completing treatment (P = 0.008), while for mumps and rubella, no statistically significant difference was observed. Importantly, our study clearly demonstrated positive seroconversion rates for measles (97.5%), mumps (81.0%), and rubella (93.2%), with antibody levels rising across the board and peaking at around 6 months following revaccination. However, 6 months after revaccination, a downtrend of antibody titer levels was observed, which is comparatively earlier than the waning immunity observed in healthy children. Furthermore, we found MMR revaccination to be safe, with only a single adverse reaction (local pain at the injection site) reported.

CONCLUSIONS

MMR revaccination is immunogenic for the population. We suggest periodic monitoring of antibody titers, in addition to a booster vaccination, although the optimal timing of booster vaccination remains to be investigated further.

MMR vaccination timing and long-term immunity among childhood cancer survivors

Long-term seroprotection against the measles and mumps viruses has not been reported in childhood cancer survivor (CCS) who received two-lifetime doses of the measles, mumps, and rubella (MMR) vaccine. We performed a retrospective study of measles and mumps titers among 55 CCS who received standard chemotherapy and two MMR vaccinations at any time. Over 75% of CCS who received at least one MMR prior to their cancer diagnosis had a negative or equivocal titer to measles or mumps. In contrast, all CCS who received the MMR series following their cancer treatment demonstrated long-term seroprotection to both viruses at a mean of 8.2 years after their last vaccination.

Herpes Simplex Virus and Varicella Zoster Virus Infections in Cancer Patients

Herpes simplex virus (HSV) and varicella zoster virus (VZV) are alpha herpesviruses that establish life-long latent infection in neuronal ganglia after primary infection. Periodic reactivation of these viruses results in recurrent infections that can have significant impact on patients' quality of life. HSV commonly causes oral and genital mucocutaneous infections whereas VZV is responsible for varicella/chickenpox and herpes zoster/shingles, but cancer patients are at particularly higher risk of complications including disseminated and visceral infections due to impaired cell-mediated immunity. While diagnosis of more common HSV and/or VZV infections is frequently clinically based, immunocompromised hosts may have atypical skin presentation or visceral involvement. Thus, diagnostic confirmation using virus-specific tests such as polymerase chain reaction or immunohistochemical staining is crucial in some cases. Oral acyclovir, valacyclovir and famciclovir are usually used for mild to moderate infections and intravenous acyclovir is the drug of choice for severe or disseminated infections. Foscarnet can be used when acyclovir-resistance is confirmed or suspected. Pharmaceutical prophylaxis against HSV and/or VZV should be considered in high-risk cancers patients. Currently, there is no commercially available vaccine against HSV, but VZV vaccines are available to prevent varicella and zoster.

Assessment of Humoral Immunity to Measles Virus in Cancer Survivor Children after Chemotherapy: A Case-Control Study

This case-control study was conducted to determine the antibody titer against the measles virus in childhood cancer survivors' post-chemotherapy treatment to determine the patient's immune status against the measles virus. We enrolled 38 children who were in complete remission and whose treatments had been stopped for at least 3 months and 38 age and sex-matched healthy controls. We analyzed the medical records of the cancer survivors, and each study participant's serum sample was analyzed by the ELISA method to determine the antibody titer against measles. The cancer survivors had significantly lower measles antibody titers than the healthy control participants, and 78.9% of cancer survivors were unprotected (seronegative) compared to 7.9% in healthy controls. After multivariate analysis, there was no statistically significant factor associated with loss of protective humoral immunity against measles. These results underline the need for post-chemotherapy measles antibody testing and revaccination of seronegative survivors.

PEPtalk 3: oral aciclovir is equivalent to varicella zoster immunoglobulin as postexposure prophylaxis against chickenpox in children with cancer - results of a multicentre UK evaluation

OBJECTIVE

To compare the occurrence of chickenpox in children with cancer who received varicella immunoglobulin (VZIG) or aciclovir as postexposure prophylaxis (PEP).

DESIGN

Prospective multicentre service evaluation of children with cancer who received either VZIG or aciclovir as PEP following significant exposure to varicella zoster virus (VZV) over a 24-month period from May 2018.

SETTING

Data were collected from 9 UK Paediatric Oncology Primary Treatment Centres.

PATIENTS

Children under 16 years old with a diagnosis of cancer and/or previous haematopoietic stem cell transplant who were VZV seronegative at exposure and/or diagnosis and received PEP following significant VZV exposure.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of breakthrough varicella within 6 weeks of VZV exposure and treatment with PEP.

RESULTS

A total of 105 eligible patients were registered with a median age of 4.9 years (range 1.1-10.5 years). Underlying diagnoses were acute leukaemia (64), solid tumours (22), Langerhans cell histiocytosis (9), central nervous system (CNS) tumours (8) and other (2). Aciclovir was received by 86 patients (81.9%), 18 received VZIG (17.1%) and 1 valaciclovir (0.9%). There were seven reported break-through VZV infections in 103 patients at follow-up (7/103, 6.8%). Clinical VZV developed in 5/84 of the aciclovir group (6.0%, 95% CI 2.0 to 13.3) and 2/18 of VZIG group (11.1%, 95% CI 1.4 to 34.7). All breakthrough infections were either mild (5/7) or moderate (2/7) in severity.

CONCLUSION

Aciclovir is a safe and effective alternative to VZIG as VZV PEP in children with cancer and should be considered as standard of care.

Estimating the number of US children susceptible to measles resulting from COVID-19-related vaccination coverage declines

Measles elimination hinges on vaccination coverage remaining above 95% to retain sufficient community protection. Recent declines in routine measles vaccinations due to the COVID-19 pandemic coupled with prior models indicating the country was close to the 92% herd immunity benchmark are a cause for concern. We evaluated population-level measles susceptibility in the US, including sensitivity analyses accounting for pandemic-related impacts on immunization. We estimated the number of children aged 0–18 currently susceptible to measles and modeled susceptibility proportions in decreased vaccination scenarios. Participants were respondents to the NIS-Teen survey between 2008 and 2017 that also had provider-verified vaccination documentation. The exposure of interest was vaccination with a measles-containing vaccine (MCV), and the age at which they were vaccinated for all doses given. Using age at vaccination, we estimated age-based probabilities of vaccination and modeled population levels of MCV immunization and immunity vs. susceptibility. Currently, 9,145,026 children (13.1%) are estimated to be susceptible to measles. With pandemic level vaccination rates, 15,165,221 children (21.7%) will be susceptible to measles if no attempt at catch-up is made, or 9,454,436 children (13.5%) if catch-up vaccinations mitigate the decline by 2–3%. Models based on increased vaccine hesitancy also show increased susceptibility at national levels, with a 10% increase in hesitancy nationally resulting in 14,925,481 children (21.37%) susceptible to measles, irrespective of pandemic vaccination levels. Current levels of measles immunity remain below herd immunity thresholds. If pandemic-era reductions in childhood immunization are not rectified, population-level immunity to measles is likely to decline further.

Chronic Myeloid Leukemia in Children: Immune Function and Vaccinations

Children with CML need TKI treatment for many years, and the lack of knowledge about immune dysfunction with TKI has hindered routine immunizations. This review attempts to provide an overview of the effects of TKIs licensed for children (e.g., imatinib, dasatinib, and nilotinib) on immune function, as well as its implications on immunizations. We discuss surveillance strategies (e.g., immunoglobulin blood serum levels and hepatitis B reactivation) and immunizations. All inactivated vaccines (e.g., influenza, pneumococcal, and streptococcal) can be given during the treatment of CML in the chronic phase, although their efficacy may be lower. As shown in single cases of children and adults with CML, live vaccines (e.g., varicella, measles, mumps, rubella, and yellow fever) may be administered under defined circumstances with great precautions. We also highlight important aspects of COVID-19 in this patient population (e.g., the outcome of COVID-19 infection in adults with CML and in children with varying hemato-oncological diseases) and discuss the highly dynamic field of presently available different vaccination options. In conclusion, TKI treatment for CML causes humoral and cellular immune dysfunction, which is mild in most patients, and thus infectious complications are rare. Routine immunizations are important for health maintenance of children, but vaccinations for children with CML on TKI therapy should be carefully considered.

A hidden menace? Cytomegalovirus infection is associated with reduced cortical gray matter volume in major depressive disorder

Human cytomegalovirus (HCMV) infection is associated with neuropathology in patients with impaired immunity and/or inflammatory diseases. However, the association between gray matter volume (GMV) and HCMV has never been examined in major depressive disorder (MDD) despite the presence of inflammation and impaired viral immunity in a subset of patients. We tested this relationship in two independent samples consisting of 179 individuals with MDD and 41 healthy controls (HC) (sample 1) and 124 MDD participants and 148 HCs (sample 2). HCMV positive (HCMV+) and HCMV negative (HCMV-) groups within each sample were balanced on up to 11 different clinical/demographic variables using inverse probability of treatment weighting. GMV of 87 regions was measured with FreeSurfer. There was a main effect of HCMV serostatus but not diagnosis that replicated across samples. Relative to HCMV- subjects, HCMV+ subjects in sample 1 showed a significant reduction of volume in six regions (p_uncorrected < 0.05). The reductions in GMV of the right supramarginal gyrus (standardized beta coefficient (SBC) = -0.26) and left fusiform gyrus (SBC = -0.25) in sample 1 were replicated in sample 2: right supramarginal gyrus (p_uncorrected < 0.05, SBC = -0.32), left fusiform gyrus (P_FDR < 0.01, SBC = -0.51). Posthoc tests revealed that the effect of HCMV was driven by differences between the HCMV+ and HCMV- MDD subgroups. HCMV IgG level, a surrogate marker of viral activity, was correlated with GMV in the left fusiform gyrus (r = -0.19, P_uncorrected = 0.049) and right supramarginal gyrus (r = -0.19, p_uncorrected = 0.043) in the HCMV+ group of sample 1. Conceivably, HCMV infection may be a treatable source of neuropathology in vulnerable MDD patients.

Seroprevalence of Measles and Mumps Antibodies Among Individuals With Cancer

Importance

Although patients with cancer are at an increased risk of infection-related complications, few studies have characterized their vulnerability to measles and mumps. Given the recent outbreaks and increased community vaccine hesitancy, understanding measles and mumps immunity within this population is vital.

Objectives

To identify a point prevalence estimate of protective measles and mumps antibodies among ambulatory patients with cancer.

Design, Setting, and Participants

In this cross-sectional study, residual clinical plasma samples were obtained from consecutive patients with cancer at Seattle Cancer Care Alliance/Fred Hutchinson Cancer Research Center in Seattle, Washington, in August 2019. These samples were tested for measles and mumps IgG using a commercial enzyme-linked immunosorbent assay. Patients without cancer were excluded from the analysis.

Exposures

Patient age, sex, self-reported race and ethnicity, primary disease, receipt of chemotherapy in the past 30 days before sample collection, hematopoietic cell transplant (HCT) history, and date of most recent intravenous immunoglobulin treatment were abstracted from electronic medical records.

Main Outcomes and Measures

Measles and mumps IgG seroprevalence, defined as the proportion of patients with positive antibody test results, was measured overall and among the subgroups.

Results

Of the 959 patients included in the analysis, 510 (53%) were male individuals and the mean (SD) age at sample collection was 60 (15) years. Most patients (576 [60%]) had a malignant solid tumor, and 383 patients (40%) had a hematologic malignant neoplasm; 146 patients (15%) had an HCT history. Overall, the seroprevalence of measles antibodies was 0.75 (95% CI, 0.72-0.78), and the seroprevalence of mumps antibodies was 0.62 (95% CI, 0.59-0.65). The lowest seroprevalences were among patients with a hematologic malignant neoplasm (0.63 for measles and 0.48 for mumps), those with a history of HCT (0.46 for measles and 0.29 for mumps), and those aged 30 to 59 years (0.49-0.63 for measles and 0.41-0.58 for mumps).

Conclusions and Relevance

In this study, 25% of ambulatory patients with cancer lacked protective antibodies for measles and 38% lacked protective antibodies for mumps. Deficits in protective antibodies underscore patients' increased risk during outbreaks and emphasize the need for community-based efforts to increase herd immunity to protect this population.

Waning Vaccine Immunity and Vaccination Responses in Children Treated for Acute Lymphoblastic Leukemia: A Canadian Immunization Research Network Study

BACKGROUND

There is no uniform guideline for postchemotherapy vaccination of children with acute lymphoblastic leukemia (ALL). We evaluated waning immunity to 14 pneumococcal serotypes, pertussis toxin (PT), tetanus toxoid (TT) and varicella, and immunogenicity of postchemotherapy diphtheria, tetanus, pertussis, hepatitis B, polio, and Haemophilus influenzae type b (DTaP-IPV-Hib) and pneumococcal vaccination among previously vaccinated children treated for ALL.

METHODS

This was a multicenter trial of children with ALL enrolled 4-12 months postchemotherapy completion. Exclusion criteria included: infant ALL, relapsed ALL, and stem cell transplant recipients. Immunocompetent children were recruited as controls. Postchemotherapy participants received DTaP-IPV-Hib and 13-valent pneumococcal conjugate vaccine (PCV13) concurrently, followed by 23-valent pneumococcal polysaccharide vaccine (PPV23) 2 months later. Serology was measured at baseline, 2 and 12 months postvaccination. Adverse events were captured via surveys.

RESULTS

At enrollment, postchemotherapy participants (n = 74) were less likely than controls (n = 78) to be age-appropriately immunized with DTaP (41% vs 89%, P < .001) and PCV (59% vs 79%, P = .008). Geometric mean concentrations (GMCs) to TT, PT, PCV serotypes, and varicella were lower in postchemotherapy participants than controls after adjusting for previous vaccine doses (P < .001). Two months postvaccination, GMCs to TT, PT, and PCV serotypes increased from baseline (P < .001 for all antigens) and remained elevated at 12 months postvaccination. Antibody levels to PPV23 serotypes also increased postvaccination (P < .001). No serious adverse events were reported.

CONCLUSIONS

Children treated for ALL had lower antibody levels than controls against pneumococcal serotypes, tetanus, pertussis, and varicella despite previous vaccination. Postchemotherapy vaccination with DTaP-IPV-Hib, PCV13, and PPV23 was immunogenic and well tolerated. Children with ALL would benefit from systematic revaccination postchemotherapy.

CLINICAL TRIALS REGISTRATION

NCT02447718.

Immune function in childhood cancer survivors: a Children's Oncology Group review

Childhood cancer and its treatment often impact the haematopoietic and lymphatic systems, with immunological consequences. Immunological assessments are not routinely included in surveillance guidelines for most survivors of childhood cancer, although a robust body of literature describes immunological outcomes, testing recommendations, and revaccination guidelines after allogeneic haematopoietic cell transplantation. Survivorship care providers might not fully consider the impaired recovery of a child's immune system after cancer treatment if the child has not undergone haematopoietic cell transplantation. We did a scoping review to collate the existing literature describing immune function after childhood cancer therapy, including both standard-dose chemotherapy and high-dose chemotherapy with haematopoietic cell rescue. This Review aims to summarise: the principles of immunology and testing of immune function; the body of literature describing immunological outcomes after childhood cancer therapy, with an emphasis on the risk of infection, when is testing indicated, and preventive strategies; and knowledge gaps and opportunities for future research.

Vaccination in pediatric cancer survivors: Vaccination rates, immune status, and knowledge regarding compliance

BACKGROUND

Vaccination recommendations for childhood cancer survivors are ambiguous. Limited data exist on vaccination rates and patient/caregiver knowledge of vaccination postchemotherapy.

PROCEDURE

A single-institution study of childhood cancer survivors treated from 1996 to 2018. Study included a retrospective chart review assessing patient's vaccination status, survey of patient's/caregiver's knowledge/beliefs regarding vaccination postchemotherapy, and assessment of immunoglobulin titers.

RESULTS

A total of 120 patient charts were included. Vaccination records were available for 82% (98/120) of patients, 57% (56/98) were up to date with vaccinations before chemotherapy, and 83% (81/98) received vaccinations after chemotherapy. Children who resumed vaccination postchemotherapy were younger at cancer diagnosis compared to those who did not resume vaccination (2 vs 4 years, P < .02). Median time since chemotherapy was higher in vaccinated versus unvaccinated patients (107 vs 60 months, P < .02). Immunoglobulin titers were assessed in 27 patients, and 74% (20/27) were not immune to one or more infections tested. Lack of immunity to pneumococcal strains was the most common. There was no difference in median age at diagnosis or time since chemotherapy completion in immune versus nonimmune patients. In 33 surveyed patients/caregivers, 33% (11/33) were not advised about resuming vaccinations postchemotherapy. Over one-third (12/33) of respondents were concerned about vaccination safety after chemotherapy, although 88% (29/33) agreed they would vaccinate if recommended by their pediatrician/pediatric oncologist.

CONCLUSIONS

Most childhood cancer survivors resume vaccinations postchemotherapy. Considerable variability exists in vaccination timing after chemotherapy. Pediatric oncologists play a central role in educating patients/pediatricians about vaccination recommendations postchemotherapy.

Severe infections following treatment for childhood cancer: a report from CYP-C

Little is known about infections occurring after childhood cancer treatment. We assessed the risk of severe infection postcancer therapy in survivors of leukemia compared to other cancer types. We performed a population-based cohort study of children <15 years of age diagnosed with cancer (2001-2016), alive and relapse-free 30 days after treatment completion. The risk of severe infection in both groups was estimated using subdistribution proportional hazard regression. We identified 6148 survivors (1960 with leukemia). The cumulative incidence (95% confidence interval) of severe infections at 3 years was 0.70% (0.40-1.2%) in leukemia and 0.51% (0.32-0.79%) in other cancers. The risk of severe infection was not statistically different in leukemia survivors compared to other cancer types in univariate and multivariate analysis (adjusted hazard ratio: 1.40, 95% CI: 0.69-2.85). No significant association was found between a history of leukemia and an increased risk of severe infection after treatment, compared to other cancer types.

Post-Chemotherapy Titer Status and Need for Revaccination After Treatment for Childhood Cancer

Objectives. To evaluate the strategy of checking vaccine titers after completion of chemotherapy. Study Design. Retrospective review of pediatric oncology patients who completed chemotherapy. Demographics, post-chemotherapy titers, and absolute lymphocyte counts (ALCs) were analyzed. Results. Ninety patients met inclusion criteria, and 87% of patients had at least one titer checked. Comparing patients <7 years and those ≥7 years at diagnosis, there was no difference in incidence of negative titers except mumps; those <7 years old were more likely to have negative titers (58% vs 20%, P = .003). Comparing those <13 years old to ≥13 years old, there was no difference in negative titers except mumps (45% vs 19%, P = .02) and tetanus (44% vs 0%, P = .002). No patient maintained all protective titers after completion of chemotherapy. Time to ALC recovery was not predictive of positive titers. Conclusion. Checking titers after chemotherapy is not recommended. Providers should assume loss of immunity.

The Impact of Chemotherapy after Pediatric Malignancy on Humoral Immunity to Vaccine-Preventable Diseases

Background/Aim

The antibody titer of vaccine-preventable diseases in pediatric patients who underwent chemotherapy was assessed in order to evaluate the seroprotection after treatment and the feasibility and the efficacy of a policy of revaccination.

Methods

Serum antibody titers of 55 patients for hepatitis B (HBV), rubella, varicella-zoster (VZV), measles, mumps, polio viruses, Clostridium tetani (C. tetani) and Streptococcus pneumoniae (S. pneumoniae) were analysed.

Results: After chemotherapy, a lack of protective antibody titers against HBV, rubella, VZV, measles, mumps, polio viruses, C. tetani, and S. pneumoniae was found in 53%, 45%, 46%, 46%, 43%, 21–26%, 88% and 55% of patients, respectively. In 49 of 55 patients who were tested both before and after chemotherapy for at least a pathogen, the loss of immunity for HBV, rubella, VZV, measles, mumps, polio viruses and C. tetani was respectively 39%, 43%, 38%, 42%, 32%, 33%, and 80%. A low number of B-lymphocytes was associated with the loss of immunity against measles (p=0.04) whereas a high number of CD8+ T-lymphocytes was associated with the loss of immunity against VZV (p=0.03). A single booster of vaccine dose resulted in a seroprotection for HBV, rubella, VZV, measles, mumps, polio viruses, C. tetani and S. pneumoniae in 67%, 83%, 80%, 67%, 33%, 100%, 88% and 67% of patients, respectively.

Conclusions

We confirm that seroprotection for vaccine-preventable diseases is affected by treatment for pediatric malignancy. A single booster dose of vaccine might be a practical way to restore vaccine immunity in patients after chemotherapy.

Simultaneous parotitis and ipsilateral herpes zoster ophthalmicus: coincidence?

A 43-year-old previously healthy man presented to the primary care clinic with concurrent ipsilateral viral parotitis and herpes zoster ophthalmicus. The patient experienced painful swelling below the right ear as well as painful vesicles on the right forehead, eyelid and cheek in the V1 dermatomal region. There were no lesions in the oral cavity or nose. Antibody titres confirmed active varicella zoster virus in the absence of mumps or herpes simplex virus 1 and 2 and unilateral parotitis were confirmed to be non-suppurative by the patient's primary care physician and the neurologist. Both conditions resolved within 3 weeks with appropriate treatment.

Vaccination of patients with haematological malignancies who did not have transplantations: guidelines from the 2017 European Conference on Infections in Leukaemia (ECIL 7)

Patients with haematological malignancies are at high risk of infection because of various mechanisms of humoral and cell-mediated immune deficiencies, which mainly depend on underlying disease and specific therapies. Some of these infections are vaccine preventable. However, these malignancies are different from each other, and the treatment approaches are diverse and rapidly evolving, so it is difficult to have a common programme for vaccination in a haematology ward. Additionally, because of insufficient training about the topic, vaccination is an area often neglected by haematologists, and influenced by cultural differences, even among health-care workers, in compliance to vaccines. Several issues are encountered when addressing vaccination in haematology: the small size of the cohorts that makes it difficult to show the clinical benefits of vaccination, the subsequent need to rely on biological parameters, their clinical pertinence not being established in immunocompromised patients, scarcity of clarity on the optimal timing of vaccination in complex treatment schedules, and the scarcity of data on long-term protection in patients receiving treatments. Moreover, the risk of vaccine-induced disease with live-attenuated vaccines strongly limits their use. Here we summarise guidelines for patients without transplantations, and address the issue by the haematological group-myeloid and lymphoid-of diseases, with a special consideration for children with acute leukaemia.

Determinants of low measles vaccination coverage in children living in an endemic area

Measles outbreaks were recently reported in Europe due to low immunization rates. In this scenario, identifying the reasons of no vaccination is crucial to set up strategies to improve immunization rate. A cross-sectional study was conducted to investigate the determinants of missed vaccination in children living in Southern Italy, during the 2016 outbreak. A standardized face-to-face questionnaire was used to record demographic data, immunization status, and reasons for missed vaccination. A total of 1141 children (median age 86 months, male 47.2%) was enrolled, 77.8% of the children were adequately vaccinated for age, 6.3% were incompletely vaccinated for age, and 15.9% did not receive any vaccine dose. Vaccination rate and reasons for not vaccinating significantly varied according to age, with children ≤ 24 months showing the lowest rate (67.8%). Reasons for not vaccinating included fear for side effects (51%), presence of underlying chronic conditions (12.2%), skip scheduled appointment (12.2%), refusal of vaccination (10.3%), acute illnesses (7.2%), and allergy to eggs (4.6%). The presence of underlying condition was a risk factor for inadequate immunization (p < 0.0001). Only 4.7% of conditions were true contraindications to vaccine administration.Conclusion: We reported inadequate measles immunization rate in Southern Italy, with lowest rates in children ≤ 2 years or with underlying conditions. Only a minority had true contraindications to vaccine uptake. Implementation strategies addressed to health-care professionals and families should focus on the reported determinants to increase measles vaccination coverage. What is Known: • Measles is a viral, highly communicable disease, preventable by vaccine. • Measles elimination in Europe failed as demonstrated by outbreaks in several countries, due to low immunization rates. What is New: • Inadequate measles immunization rate due to false contraindications in Southern Italy, with lowest rates in children ≤ 2 years. • The presence of underlying disease is a risk factor for inadequate immunization.

PEPtalk2: results of a pilot randomised controlled trial to compare VZIG and aciclovir as postexposure prophylaxis (PEP) against chickenpox in children with cancer

OBJECTIVE

To determine the likely rate of patient randomisation and to facilitate sample size calculation for a full-scale phase III trial of varicella zoster immunoglobulin (VZIG) and aciclovir as postexposure prophylaxis against chickenpox in children with cancer.

DESIGN

Multicentre pilot randomised controlled trial of VZIG and oral aciclovir.

SETTING

England, UK.

PATIENTS

Children under 16 years of age with a diagnosis of cancer: currently or within 6 months of receiving cancer treatment and with negative varicella zoster virus (VZV) serostatus at diagnosis or within the last 3 months.

INTERVENTIONS

Study participants who have a significant VZV exposure were randomised to receive PEP in the form of VZIG or aciclovir after the exposure.

MAIN OUTCOME MEASURES

Number of patients registered and randomised within 12 months of the trial opening to recruitment and incidence of breakthrough varicella.

RESULTS

The study opened in six sites over a 13-month period. 482 patients were screened for eligibility, 32 patients were registered and 3 patients were randomised following VZV exposure. All three were randomised to receive aciclovir and there were no cases of breakthrough varicella.

CONCLUSIONS

Given the limited recruitment to the PEPtalk2 pilot, it is unlikely that the necessary sample size would be achievable using this strategy in a full-scale trial. The study identified factors that could be used to modify the design of a definitive trial but other options for defining the best means to protect such children against VZV should be explored.

TRIAL REGISTRATION NUMBER

ISRCTN48257441, EudraCT number: 2013-001332-22, sponsor: University of Birmingham.

Reduced immunity to measles in adults with major depressive disorder

BACKGROUND

Depression can impair the immunogenicity of vaccine administration in adults. Whereas many vaccinations are administered in childhood, it is not known whether adolescent or adult onset depression is associated with impairments in the maintenance of protection of childhood vaccines. This study tested the hypothesis that individuals with adolescent or adult onset mood disorders would display compromised immunity to measles, a target of childhood vaccination.

METHODS

IgG antibodies to measles were quantified using a solid phase immunoassay in volunteers with bipolar disorder (BD, n = 64, mean age of onset = 16.6 ± 5.6), currently depressed individuals with major depressive disorder (cMDD, n = 85, mean age of onset = 17.9 ± 7.0), remitted individuals with a history of MDD (rMDD, n = 82, mean age of onset = 19.2 ± 8.6), and non-depressed comparison controls (HC, n = 202), all born after the introduction of the measles vaccine in the USA in 1963.

RESULTS

Relative to HC, both the cMDD group (p = 0.021, adjusted odds ratios (OR) = 0.47, confidence interval (CI) = 0.24-0.90), and the rMDD group (p = 0.038, adjusted OR = 0.50, CI = 0.26-0.97) were less likely to test seropositive for measles. Compared with unmedicated MDD participants, currently medicated MDD participants had a longer lifetime duration of illness and were less likely to test seropositive for measles.

CONCLUSIONS

Individuals with adolescent or adult onset MDD are less likely to test seropositive for measles. Because lower IgG titers are associated with increased risk of measles infection, MDD may increase the risk and severity of infection possibly because of impaired maintenance of vaccine-related protection from measles.

"My son can not attend the school because 5 classmates are unvaccinated". On the question of compulsory vaccinations and the risk for immune-compromised children into the schools: the case of paediatric cancer patients

Since 2017, 10 vaccines are compulsory for newborns in Italy and unvaccinated children are not admitted to kindergartens. Recently the Italian Government announced the perspective of reforming the law about the compulsory vaccination. A debated started about the presence, in the same class of the schools, of unvaccinated and immunocompromised children. Cancer is the one of the most important cause of immunodepression among children: after the chemoterapy, there is a period of 13–23 months in which the cancer survivors have to come back at the school and at to the “normal life” (even for psychological exigency) but remain at risk of infectious disease for the immunodepression. The most important chance to protect this subgroup of patients remains the herd immunity.

Managing varicella zoster virus contact and infection in patients on anti-rheumatic therapy

Chickenpox and shingles can be more severe and occasionally life threatening in immunosuppressed patients. As such, some groups warrant a more detailed history, serological testing and consideration of prophylaxis following contact with the virus. Active disease may also require more aggressive treatment with antivirals. Guidance for the use of varicella zoster immunoglobulin has recently been updated by Public Health England with important implications for rheumatology patients.

Late Infection-Related Mortality in Asplenic Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study

Purpose Infection-related outcomes associated with asplenia or impaired splenic function in survivors of childhood cancer remains understudied. Methods Late infection-related mortality was evaluated in 20,026 5-year survivors of childhood cancer (diagnosed < 21 years of age from 1970 to 1999; median age at diagnosis, 7.0 years [range, 0 to 20 years]; median follow-up, 26 years [range, 5 to 44 years]) using cumulative incidence and piecewise-exponential regression models to estimate adjusted relative rates (RRs). Splenic radiation was approximated using average dose (direct and/or indirect) to the left upper quadrant of the abdomen (hereafter, referred to as splenic radiation). Results Within 5 years of diagnosis, 1,354 survivors (6.8%) had a splenectomy and 9,442 (46%) had splenic radiation without splenectomy. With 62 deaths, the cumulative incidence of infection-related late mortality was 1.5% (95% CI, 0.7% to 2.2%) at 35 years after splenectomy and 0.6% (95% CI, 0.4% to 0.8%) after splenic radiation. Splenectomy (RR, 7.7; 95% CI, 3.1 to 19.1) was independently associated with late infection-related mortality. Splenic radiation was associated with increasing risk for late infection-related mortality in a dose-response relationship (0.1 to 9.9 Gy: RR, 2.0; 95% CI, 0.9 to 4.5; 10 to 19.9 Gy: RR, 5.5; 95% CI, 1.9 to 15.4; ≥ 20 Gy: RR, 6.0; 95% CI, 1.8 to 20.2). High-dose alkylator chemotherapy exposure was also independently associated with an increased risk of infection-related mortality (RR, 1.9; 95% CI, 1.1 to 3.4). Conclusion Splenectomy and splenic radiation significantly increase risk for late infection-related mortality. Even low- to intermediate-dose radiation exposure confers increased risk, suggesting that the spleen is highly radiosensitive. These findings should inform long-term follow-up guidelines for survivors of childhood cancer and should lead clinicians to avoid or reduce radiation exposure involving the spleen whenever possible.

Humoral immune response of childhood acute lymphoblastic leukemia survivors against the measles, mumps, and rubella vaccination

BACKGROUND

There is a great risk of infection with viral-vaccine-preventable diseases like measles, mumps, and rubella (MMR) infections after the end of chemotherapy treatment of children with acute lymphoblastic leukemia (ALL), which could have been prevented with MMR vaccination. Previous studies reported widely variable rates of seropositivity (seroprotection) for MMR after ALL treatment ends. Also, few studies evaluated the response to MMR booster vaccinations after the end of ALL treatment and reported unclear and difficult to interpret results.

MATERIAL AND METHODS

This retrospective cross-sectional study evaluated the prevalence of seropositive (protection) antibody titer levels for MMR among ALL childhood survivors who were followed-up at Jeddah Oncology Center, Saudi Arabia. The aim of the study was also to investigate and analyze the response of seronegative patients to a booster MMR vaccination.

RESULTS

Fifty-seven ALL children were evaluated. Thirty-five patients (61.4%) were seropositive/seroprotected and the remaining 22 patients (38.6%) were seronegative for MMR. ALL Children under the age of 5 years had a higher prevalence of seronegative titers. Interestingly, the prevalence of seroprotection decreased as the time interval increased post-treatment, while seroconversion rates after administering a booster MMR vaccine were 57.1%, 87.5%, and 78.6%, respectively for MMR.

CONCLUSION

We suggest the need for booster MMR vaccination, especially for ALL children under the age of 5 years and those who experienced a protracted time interval post-treatment.

Assessment of Humoral Immunity to Hepatitis B, Measles, Rubella, and Mumps in Children After Chemotherapy

BACKGROUND

Cancer survival rates and longevity of patients after therapy have significantly improved during the last few decades. Therefore, lasting protection against infections should be provided.

PROCEDURE

A total of 162 children diagnosed with acute lymphoblastic leukemia, acute myelogenous leukemia, solid tumors, non-Hodgkin lymphoma, and Hodgkin lymphoma were enrolled in the study. Antibody levels against hepatitis B virus was assessed both at the time of diagnosis and within 6 months after completion of chemotherapy. However, measles, mumps, and rubella (MMR) antibodies levels were measured just within 6 months after completion of chemotherapy.

RESULTS

Anti-HBs antibody titers had decreased below the protective level after treatment in 25 of 96 patients having protective antibody levels for hepatitis B virus before therapy. In 66 patients without pretreatment protective levels of antibody, in spite of the immunization during chemotherapy, only 6 of them were found to be anti-HBS positive after treatment. In 153 patients previously vaccinated with MMR, 19 had protective antibody titers after treatment. MMR seropositivities were negatively correlated to age as expected.

CONCLUSIONS

Our data demonstrate that a significant number of children lose preexisting humoral immunity against MMR and hepatitis B after completion of chemotherapy.

Measles Outbreak in Pediatric Hematology and Oncology Patients in Shanghai, 2015

Background:

Despite substantial progress toward measles control are making in China, measles outbreaks in immunocompromised population still pose a challenge to interrupt endemic transmission. This study aimed to investigate the features of measles in pediatric hematology and oncology patients and explore the reasons behind the outbreak.

Methods:

We collected demographic, epidemiological, and clinical data of immunocompromised measles children. All suspected measles cases were laboratory-confirmed based on the presence of measles IgM and/or identification of measles RNA. The clinical data were statistically analyzed by t-test for continuous variables and Fisher's exact test for categorical variables.

Results:

From March 9 to July 25 in 2015, a total of 23 children with malignancies and post hematopoietic stem cell transplantation (post-HSCT) were notified to develop measles in Shanghai. Of these 23 patients with the median age of 5.5 years (range: 11 months–14 years), 20 (87.0%) had received 1–3 doses of measles vaccine previously; all patients had fever with the median fever duration of 8 days; 21 (91.3%) had cough; 18 (78.3%) had rash; 13 (56.5%) had Koplik's spot; 13 (56.5%) had complications including pneumonia and acute liver failure; and five (21.7%) vaccinated patients died from severe pneumonia or acute liver failure. Except the first patient, all patients had hospital visits within 7–21 days before measles onset and 20 patients were likely to be exposed to each other.

Conclusions:

The outcome of measles outbreak in previously vaccinated oncology and post-HSCT pediatric patients during chemotherapy and immunosuppressant medication was severe. Complete loss of protective immunity induced by measles vaccine during chemotherapy was the potential reason. Improved infection control practice was critical for the prevention of measles in malignancy patients and transplant recipients.

Immunization status in childhood cancer survivors: A hidden risk which could be prevented

BACKGROUND

A limited number of studies have examined the vaccine-specific antibody status of children with cancer. There are disagreements over the guidelines for postcancer immunization strategy.

METHODS

Our study was an observational, cross-sectional retrospective review of data collected on children who were seen in the outpatient clinic at King Abdullah Medical City, Oncology Center, Jeddah, the Kingdom of Saudi Arabia. Our aim was to evaluate the seropositive status to vaccine-preventable diseases: measles, mumps, rubella, diphtheria, tetanus, polio, and Haemophilus influenzae type B (HIB) in childhood cancer survivors at our center in order to plan future vaccination for these children and establish a simple revaccination schedule.

RESULTS

Forty-seven patients (21 boys and 26 girls) were included in the study. Age at the time of cancer diagnosis (mean±standard deviation) was 5.68±3.79 years and age at test sampling was 10.68±3.79 years. Acute leukemia was the most common cancer (49% of patients), followed by lymphoma (28%), brain tumors (13%), and solid tumors (10%). Treatment intensities (according to the Treatment Intensity Rating Scale, version 3.0; ITR-3) were 2, 3, and 4 for 26 patients (55%), 20 patients (43%), and one patient (2.1%), respectively. We found that 93% of our patients were considered seronegative (unprotected) for at least one vaccine-preventable disease. The seronegative rates for measles, mumps, rubella, diphtheria, tetanus, polio, and HIB were 46.8%, 36.2%, 36.2%, 46.8%, 61.7%, 17.1%, and 42.6%, respectively. Criteria including age at diagnosis, age at sampling, type of malignancy, and treatment intensity were not significantly different between seropositive and seronegative patients.

CONCLUSION

Seronegative rates for vaccine-preventable diseases were very high in childhood cancer survivors, which represented a subpopulation of high-risk patients who could benefit from revaccination. We suggest a universal revaccination approach for all childhood cancer survivors, which is easily applicable and of low cost.

Clinical indicators for nursing diagnosis Ineffective protection in adolescents with cancer

ABSTRACT Objective: To investigate scientific evidence related to the term protection and clinical indicators and etiologic factors for nursing diagnosis Ineffective protection in adolescents with cancer. Method: Integrative literature review in the databases of Scopus, Web of Science, National Library of Medicine and National Institutes of Health (PubMed) and Cochrane; by intersection of the descriptors protection and childhood cancer, which resulted in seven articles. These were insufficient for a comprehension of the term protection and aspects related to its impairment, therefore it was necessary to include a further three reference books. Results: Five clinical indicators and three etiologic factors associated to Ineffective protection were identified some of which were not cited in NANDA-International. Conclusions: There are clinical and etiologic factors important for the identification of ineffective protection in adolescents with cancer.

Protection against vaccine preventable diseases in children treated for acute lymphoblastic leukemia

BACKGROUND

The objective of this retrospective study was to assess protection against vaccine preventable diseases (VPDs) in children treated for acute lymphoblastic leukemia (ALL).

PROCEDURE

Clinical characteristics and vaccination records were collected. Antibodies against VPDs were measured after completion of chemotherapy and after a booster dose of vaccine. Immunization status of household members was evaluated.

RESULTS

Sixty children were included. Median interval between the end of chemotherapy and enrolment in the study was 13 months (range 1-145). At ALL diagnosis, 81.3% of the children were up to date with their vaccination schedule. This proportion decreased to 52.9% at enrolment. Among the parents, 21% were up to date with their immunization schedule and 42% had received seasonal influenza vaccination. After chemotherapy, less than 50% of the patients were seroprotected against tetanus, diphtheria, polio 3, Haemophilus influenzae type b (Hib), and mumps and no more than 80% were seroprotected against polio 1 and 2, measles, rubella, and varicella. After a booster dose of vaccine, the rate of protection increased to over 90% for each of the following antigens: TT, DT, polio 1, Hib, measles, and rubella. Nevertheless, polio 3, mumps, and varicella-zoster virus antibodies titers/concentrations remained below seroprotective thresholds in over 20% of the patients.

CONCLUSIONS

After chemotherapy for ALL, most of the children were not protected against VPDs. As the majority mounted a robust response to booster vaccines, efforts need to be done to improve protection against VPDs by implementing a systematic vaccine booster schedule. This could also be helped by reinforcing household members' immunization.

In Vivo Efficacy of Measles Virus Fusion Protein-Derived Peptides Is Modulated by the Properties of Self-Assembly and Membrane Residence

Measles virus (MV) infection is undergoing resurgence and remains one of the leading causes of death among young children worldwide despite the availability of an effective measles vaccine. MV infects its target cells by coordinated action of the MV hemagglutinin (H) and fusion (F) envelope glycoproteins; upon receptor engagement by H, the prefusion F undergoes a structural transition, extending and inserting into the target cell membrane and then refolding into a postfusion structure that fuses the viral and cell membranes. By interfering with this structural transition of F, peptides derived from the heptad repeat (HR) regions of F can inhibit MV infection at the entry stage. In previous work, we have generated potent MV fusion inhibitors by dimerizing the F-derived peptides and conjugating them to cholesterol. We have shown that prophylactic intranasal administration of our lead fusion inhibitor efficiently protects from MV infection in vivo We show here that peptides tagged with lipophilic moieties self-assemble into nanoparticles until they reach the target cells, where they are integrated into cell membranes. The self-assembly feature enhances biodistribution and the half-life of the peptides, while integration into the target cell membrane increases fusion inhibitor potency. These factors together modulate in vivo efficacy. The results suggest a new framework for developing effective fusion inhibitory peptides.

IMPORTANCE

Measles virus (MV) infection causes an acute illness that may be associated with infection of the central nervous system (CNS) and severe neurological disease. No specific treatment is available. We have shown that fusion-inhibitory peptides delivered intranasally provide effective prophylaxis against MV infection. We show here that specific biophysical properties regulate the in vivo efficacy of MV F-derived peptides.

Varicella in pediatric oncology patients in the post-vaccine era-Analysis of routine hospital data from Bavaria (Germany), 2005-2011

Varicella in oncology patients can result in serious complications. We analyzed trends in hospitalization rates and characteristics of pediatric oncology and non-oncology patients hospitalized with varicella during the first 7 years after introduction of routine varicella vaccination. Our data included children <17 years of age with an International Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) main or secondary discharge diagnosis of varicella identified by annual database queries in 22-29 pediatric hospitals in Bavaria (Germany) in 2005-2011. Of a total of 1,245 varicella-associated hospitalizations, 42 children (median age 4 years, interquartile range 3-5) had an underlying malignancy (67% with acute lymphoblastic leukemia). Overall, additional diagnoses potentially associated with varicella were reported less often in oncology than in non-oncology varicella patients (62% vs. 77%, p = 0.041), suggesting earlier hospitalization of high-risk patients. Acute hematological diagnoses (29% vs. 3%, p < 0.001) and coinfections (invasive 12% vs. 2%, p = 0.001; noninvasive 19% vs. 8%, p = 0.019) were more frequent, whereas neurological (5% vs. 19%, p = 0.023) and upper respiratory tract diagnoses (2% vs. 16%, p = 0.014) were less frequent in oncology compared to non-oncology varicella patients. Oncology varicella patients showed a longer hospital stay (median 5 vs. 3 days, p < 0.001). Hospitalization rates in non-oncology varicella patients declined constantly since 2006, from 114.8 (2006) to 30.5 (2011) per 1,000 pediatric beds. The rates of varicella-associated hospitalizations in oncology patients indicated an overall decreasing trend (3.8, 1.9, 4.6, 3.5, 0.4, 2.1 and 0.6 cases per 1,000 pediatric beds in 2005-2011). Thus, pediatric oncology patients potentially profit from herd protection effects, resulting from increasing vaccine coverage in the general population.

Estimating the Number of Measles-Susceptible Children and Adolescents in the United States Using Data From the National Immunization Survey-Teen (NIS-Teen)

Despite high measles vaccination rates in the United States, imported measles cases have led to outbreaks in the United States. These outbreaks have not led to sustained measles transmission; however, with each birth cohort of children not fully vaccinated against measles, measles-susceptible individuals accumulate in the population. The total number of measles-susceptible children and adolescents in the United States is unknown. We used age-specific measles vaccination data from the National Immunization Survey-Teen (2008-2013) to estimate the number of measles-susceptible children aged 17 years or younger, accounting for vaccine effectiveness, infant protection from maternal antibodies, and loss of immunity following childhood cancer treatment. Approximately 12.5% of US children and adolescents are susceptible to measles, with the highest levels of susceptibility being observed in children aged 3 years or younger (24.7% are susceptible to measles). In sensitivity analyses, we found that a sustained decrease in measles vaccination coverage from 91.9% (2013 level) to 90.0% (2009 level) would add nearly 1.2 million susceptible children and adolescents (thus making 14.2% of those aged 17 years or younger susceptible to measles). This reemphasizes the need for high measles vaccination coverage to support population-level immunity and prevent reestablishment of indigenous measles transmission in the United States.

Progress in Treatment of Viral Infections in Children with Acute Lymphoblastic Leukemia

In children, the most commonly encountered type of leukemia is acute lymphoblastic leukemia (ALL). An important source of morbidity and mortality in ALL are viral infections. Even though allogeneic transplantations, which are often applied also in ALL, carry a recognized risk for viral infections, there are multiple factors that make ALL patients susceptible to viral infections. The presence of those factors has an influence in the type and severity of infections. Currently available treatment options do not guarantee a positive outcome for every case of viral infection in ALL, without significant side effects. Side effects can have very serious consequences for the ALL patients, which include nephrotoxicity. For this reason a number of strategies for personalized intervention have been already clinically tested, and experimental approaches are being developed. Adoptive immunotherapy, which entails administration of ex vivo grown immune cells to a patient, is a promising approach in general, and for transplant recipients in particular. The ex vivo grown cells are aimed to strengthen the immune response to the virus that has been identified in the patients' blood and tissue samples. Even though many patients with weakened immune system can benefit from progress in novel approaches, a viral infection still poses a very significant risk for many patients. Therefore, preventive measures and supportive care are very important for ALL patients.

The European Hematology Association Roadmap for European Hematology Research: a consensus document

The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap.The EHA Roadmap identifies nine 'sections' in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders.The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients.

Vaccine-Derived Immunity in Children With Cancer-Analysis of Anti-Tetanus and Anti-Diphtheria Antibodies Changes after Completion of Antineoplastic Therapy

BACKGROUND

Cancer survival rates and longevity of patients after therapy have significantly improved during the last decades. Thus durable protection against infections should be provided. The aim of the study was to compare the levels of vaccine-derived antibodies in children with cancer compared to those of healthy children and to investigate how therapy influences the levels of specific antibodies.

PROCEDURE

A group of 40 children, diagnosed with acute lymphoblastic leukemia (ALL) or solid tumor (ST), followed in Poznan University of Medical Sciences Department of Pediatric Hematology, Oncology and Bone Marrow Transplantation, were recruited for evaluation of humoral immunity. Antibody levels were checked before treatment and 3, 6, and 12 months after treatment.

RESULTS

In patients with ALL or ST, levels of IgG against tetanus and diphtheria were significantly lower than in the control group. Among ALL patients, 9% remained negative for tetanus and diphtheria antibodies 12 months after therapy. Among patients with ST 3 months after chemotherapy, there were no protective antibodies in 12% against tetanus, and in 18% against diphtheria. All patients reconstituted immunity 6 and 12 months after therapy.

CONCLUSIONS

Our data show that a considerable number of cancer patients lose immunity against diphtheria and tetanus after therapy. Compared to ST, patients with ALL lose protective antibody levels more often. Patients with ST reconstituted antibodies after the treatment cessation, while levels in ALL patients remained low.

Failure of a Single Varicella Vaccination to Protect Children With Cancer From Life-Threatening Breakthrough Varicella

We report 2 children with life-threatening breakthrough varicella. Both had received 1 varicella vaccination before onset of cancer. Despite treatment with intravenous acyclovir, 1 child died of disseminated varicella. Because similar fatal cases have been reported, high-risk immunocompromised children with 1 varicella vaccination may warrant the same varicella prophylaxis as immunocompromised children who have never been vaccinated.

Vaccination in patients with primary immune deficiency, secondary immune deficiency and autoimmunity with immune regulatory abnormalities

Vaccination has been an important healthcare measure in preventing infectious diseases. The response to vaccination is reduced in immunocompromised patients, primary immune deficiency (PID) and secondary immune deficiency (SID), but vaccination studies still demonstrated a protective effect resulting in reducing complications, hospitalization, treatment costs and even mortality. The primary physician and the specialist directing patient care are responsible for vaccination. Live vaccines are contraindicated in patients with severe immune impairment, killed vaccines are highly recommended in PID and SID. Criteria have been defined to distinguish high- or low-level immune impairment in the different disease entities among PID and SID patients. For patients who do not respond to diagnostic vaccination as characterized by antibody failure immunoglobulin replacement is the mainstay of therapy.