Humoral immune response after post-chemotherapy booster diphtheria-tetanus-pertussis vaccine in pediatric oncology patients

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.

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.

Immune Dysfunction After Completion of Childhood Leukemia Therapy

BACKGROUND

Children with leukemia suffer immune dysfunction from their malignancy and chemotherapy. The immune system components most affected, the degree to which immune suppression occurs, and the duration of immunodeficiency are incompletely characterized. This study measures immunologic parameters following completion of therapy.

METHODS

This is a prospective, single institution cohort study. Eligible children with acute myelogenous or acute lymphoblastic leukemia diagnosed between 1 and 21 years of age were enrolled at therapy completion. Immune parameters were assessed at the end of therapy and 6 months later: complete blood counts, immunoglobulin levels, quantitative lymphocyte subsets, mitogen-induced lymphocyte proliferation, natural killer cell function, and vaccine titers.

RESULTS

Twenty patients were evaluated; 13 (65%) were female, 15 had acute lymphoblastic leukemia (75%). Mean age at diagnosis was 7.9 years. At end of therapy, all patients had some degree of immune dysfunction. At 6 months posttherapy, persistent abnormalities included: leukopenia (25%), neutropenia (15%), lymphopenia (5%), hypogammaglobulinemia (25%), one or more subtherapeutic vaccine titers (100%), abnormal lymphocyte subset levels (20%), decreased (15%), or absent (10%) natural killer cell function and abnormal lymphocyte proliferative responses (25%).

CONCLUSIONS

All patients had multiple abnormalities at end of therapy, and all patients had some degree of persistent immune dysfunction at 6 months after completion of therapy. Clinical implications of these laboratory abnormalities are currently unknown; longer term evaluations are ongoing. We demonstrate that survivors of childhood cancer have lasting quantitative and functional immunologic defects and may remain at risk for infectious complications after completion of therapy.

Infectious complications in children with acute lymphoblastic leukemia treated in low-middle-income countries

Infections are the most important cause of morbidity and mortality in children treated for acute lymphoblastic leukemia (ALL). The rates of infection-associated mortality are up to 10-times higher in low- and middle-income countries (LMIC) than in high-income countries. The prevention, early recognition and management of infectious complications is especially challenging in LMIC because of disease and poverty-related factors, as well as the shortage of trained personnel, supplies, diagnostic tools and adequate organizational infrastructure. Children in LMIC with ALL, who are frequently underweight, are at increased risk of community-acquired pathogens, nosocomial multidrug-resistant pathogens and opportunistic microorganisms. This review summarizes the challenges of managing the major categories of infections in children receiving treatment for ALL and provides updated practical recommendations for preventing and managing these infections in LMIC.

Guidelines on vaccinations in paediatric haematology and oncology patients

OBJECTIVE

Vaccinations are the most important tool to prevent infectious diseases. Chemotherapy-induced immune depression may impact the efficacy of vaccinations in children.

PATIENTS AND METHODS

A panel of experts of the supportive care working group of the Italian Association Paediatric Haematology Oncology (AIEOP) addressed this issue by guidelines on vaccinations in paediatric cancer patients. The literature published between 1980 and 2013 was reviewed.

RESULTS AND CONCLUSION

During intensive chemotherapy, vaccination turned out to be effective for hepatitis A and B, whilst vaccinations with toxoid, protein subunits, or bacterial antigens should be postponed to the less intensive phases, to achieve an adequate immune response. Apart from varicella, the administration of live-attenuated-virus vaccines is not recommended during this phase. Family members should remain on recommended vaccination schedules, including toxoid, inactivated vaccine (also poliomyelitis), and live-attenuated vaccines (varicella, measles, mumps, and rubella). By the time of completion of chemotherapy, insufficient serum antibody levels for vaccine-preventable diseases have been reported, while immunological memory appears to be preserved. Once immunological recovery is completed, usually after 6 months, response to booster or vaccination is generally good and allows patients to be protected and also to contribute to herd immunity.

Recovery of humoral and cellular immunities to vaccine-preventable infectious diseases in pediatric oncology patients

The recovery of antibodies to various vaccine-preventable infectious diseases, humoral and cellular immunity in pediatric oncology patients were evaluated by a prospective longitudinal study for 18 months. Lymphocyte subset (CD3+, CD4+, CD8+, CD16/56+, CD19+), CD4/CD8 ratio, immunoglobulin levels, antibodies to diphtheria, pertussis, tetanus, hepatitis B, measles, mumps, and rubella were measured serially at 6 months till 18 months after stopping all chemotherapy (including maintenance chemotherapy). Twenty-eight children (hematological malignancies, n = 14; solid tumors, n = 14) were studied. The median age was 7.0 +/- 3.8 years old (range 2.6-16.2 years old). Although there was significant increase in CD3+, CD4+, CD8+, CD19+ cells, IgG, IgA, and IgM levels (P < .05), CD4+ and CD8+ counts were still below the age-specific normal range at the end of study period. At 18 months after stopping chemotherapy, 11%, 15%, 60%, 30%, 49%, and 30% of subjects remained seronegative against diphtheria, tetanus, hepatitis B, measles, mumps, and rubella. This will evolve to a significant health care problem if no further intervention is implemented, as the survival rate of pediatric oncology patients improves significantly with the improvement in various cancer treatment protocols. Near complete immune recovery was demonstrated in the subjects. Significant proportion of subjects remained susceptible to vaccine-preventable infectious diseases up to 18 months after stopping all chemotherapy.