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

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.

Human Papillomavirus Vaccination in Pediatric, Adolescent, and Young Adult Cancer Survivors-Opportunity to Address Gaps in Cancer Prevention and Survivorship

The risks of secondary cancers associated with human papillomavirus (HPV) infection are as much as three times higher for survivors of pediatric, adolescent, and young adult cancer (PYAC) compared to the general population. Despite this, HPV vaccination rates among PYAC survivors remain low. Whereas pediatric oncology providers endorse HPV vaccination of PYAC survivors, many lack the resources or opportunities to intervene. The responsibility of HPV vaccination, therefore, falls to primary care providers and practices. This article provides an overview of the challenges with HPV vaccination that are distinct to PYAC survivors and discusses potential strategies to increase HPV vaccine coverage in this population.

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.

Risk Factors for Pediatric Sepsis in the Emergency Department: A Machine Learning Pilot Study

OBJECTIVE

To identify underappreciated sepsis risk factors among children presenting to a pediatric emergency department (ED).

METHODS

A retrospective observational study (2017-2019) of children aged 18 years and younger presenting to a pediatric ED at a tertiary care children's hospital with fever, hypotension, or an infectious disease International Classification of Diseases (ICD)-10 diagnosis. Structured patient data including demographics, problem list, and vital signs were extracted for 35,074 qualifying ED encounters. According to the Improving Pediatric Sepsis Outcomes Classification, confirmed by expert review, 191 patients met clinical sepsis criteria. Five machine learning models were trained to predict sepsis/nonsepsis outcomes. Top features enabling model performance (N = 20) were then extracted to identify patient risk factors.

RESULTS

Machine learning methods reached a performance of up to 93% sensitivity and 84% specificity in identifying patients who received a hospital diagnosis of sepsis. A random forest classifier performed the best, followed by a classification and regression tree. Maximum documented heart rate was the top feature in these models, with importance coefficients (ICs) of 0.09 and 0.21, which represent how much an individual feature contributes to the model. Maximum mean arterial pressure was the second most important feature (IC 0.05, 0.13). Immunization status (IC 0.02), age (IC 0.03), and patient zip code (IC 0.02) were also among the top features enabling models to predict sepsis from ED visit data. Stratified analysis revealed changes in the predictive importance of risk factors by race, ethnicity, oncologic history, and insurance status.

CONCLUSIONS

Machine learning models trained to identify pediatric sepsis using ED clinical and sociodemographic variables confirmed well-established predictors, including heart rate and mean arterial pressure, and identified underappreciated relationships between sepsis and patient age, immunization status, and demographics.

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.

Promotion Media for Children’s Health: Applicable Study of Management Child Illness

BACKGROUND: Public understanding of immunization problems, pneumonia cases, and nutrition in children is important to improve children’s health status. Provision of attractive and illustrated media is one option to increase public knowledge in supporting the success of government programs in the health sector. AIM: The purpose of this study is as a form of promotion effort to support an increase in the immunization movement in infants, a decrease in cases of malnutrition and malnutrition, and a decrease in pneumonia cases in infants. METHODS: The research method used is qualitative and quantitative study. Researchers analyzed the promoting media and the value of benefits in the community. Qualitative analyze used content analysis to get an assessment of media from cadres and parents of children. Quantitative study used univariable analysis to see understanding of illness prevention effort. Interesting picture books for immunization, pneumonia, and malnutrition are used as the promoting media. The number of samples was 20 cadres and 20 parents of children under five, done by simple random sampling technique. RESULTS: The results showed that the media used for learning nutrition, immunization, and pneumonia material was effective for cadres and the community about easy to understand, completeness, attractive, assistance, easy to use, and practically. This is evidenced by a positive assessment of the media and increased understanding of the material from 50% to 90%. CONCLUSION: Thus, it can be said that it is necessary to provide educational media to increase public knowledge and understanding of cases that often arise in the community as a problem.

Immunization status and re-immunization of childhood acute lymphoblastic leukemia survivors

Intensive chemotherapy can cause long-lasting immunosuppression in children who survived cancer. The immunosuppression varies according to the type of cancer, intensity of chemotherapy and age of the patient. A sufficient immune reconstruction when has been completed in childhood cancer survivors, the re-vaccination program can achieve sufficient antibody levels for some of the life-threatening vaccine-preventable infectious diseases. This study evaluates the serological status of pediatric acute lymphoblastic leukemia (ALL) cases before and after the intensive chemotherapy treatment. Antibodies against measles, mumps, rubella, varicella, hepatitis A and B were tested with the enzyme-linked immunosorbent assay (ELISA) method. Antibody titers were measured firstly at the leukemia diagnosis time when the chemotherapy was not started. The second evaluation of antibody titers was studied at 6 months after the cessation of chemotherapy for all patients. Forty-six patients with the mean age of 6.1 ± 4.5 years were participated in this study. Changing to seronegative after treatment was significantly different in measles, rubella, hepatitis A and hepatitis B (p < .05). Seventy-eight (28%) antibody levels in the patients were non-protective for all diseases. Only three (7%) patients had protective antibody levels for all diseases in the sixth month of chemotherapy cessation. There was a negative correlation between patient's age and losing protective antibody levels for any vaccine-preventable disease (p < .05). Antibody levels against vaccine-preventable diseases have evident that reduced after ALL treatment at childhood. Pediatric ALL survivors must be re-vaccinated for vaccine-preventable diseases after achieving immune reconstruction.

Influence of provider recommendations to restart vaccines after childhood cancer on caregiver intention to vaccinate

PURPOSE

We studied the influence of oncology and primary care provider (PCP) recommendations on caregiver intentions to restart vaccines (e.g., catch-up or boosters) after cancer treatment.

METHODS

We surveyed primary caregivers ages 18 or older with a child who had completed cancer treatment 3-36 months prior (N = 145) about demographics, child's vaccination status, and healthcare factors (e.g., provider recommendations, barriers, preferences for vaccination). We compared these factors by caregiver's intention to restart vaccines ("vaccine intention" vs. "no intent to vaccinate") using bivariate and multivariable analyses.

RESULTS

Caregivers were primarily ages 30-39 years (54.9%), mothers (80.6%), college graduates (44.4%), non-Hispanic (89.2%), and married (88.2%). Overall, 34.5% of caregivers did not know which vaccines their child needed. However, 65.5% of caregivers reported vaccine intention. Fewer caregivers with no intention to vaccinate believed that vaccinating their child helps protect others (85.4 vs. 99.0%, p < 0.01), that vaccines are needed when diseases are rare (83.7 vs. 100.0%, p < 0.01), and that vaccines are safe (80.4 vs. 92.6%, p = 0.03) and effective (91.5 vs. 98.9%, p = 0.04) compared with vaccine intention caregivers, respectively. Provider recommendations increased caregivers' likelihood of vaccine intention (oncologist RR = 1.65, 95% CI 1.27-2.12, p < 0.01; PCP RR = 1.51, 95% CI 1.19-1.94, p < 0.01).

CONCLUSIONS

Provider recommendations positively influence caregivers' intention to restart vaccines after childhood cancer. Guidelines are needed to support providers in making tailored vaccine recommendations.

IMPLICATIONS FOR CANCER SURVIVORS

Timely vaccination after childhood cancer protects patients against vaccine-preventable diseases during survivorship. Caregivers may benefit from discussing restarting vaccinations after cancer with healthcare providers.