Impaired antibody levels to tetanus toxoid and pneumococcal polysaccharides in acute leukemias

Lymphocyte counts predict optimal timing of chemotherapy reinitiation after antivirus treatment for herpes zoster in children with leukemia

Herpes zoster (HZ) is rare in healthy children, but more prevalent in those with leukemia. Optimal timing of chemotherapy reinitiation after HZ treatment is challenging because chemotherapy suppresses immunity and increases risk of HZ relapse. We aimed to optimize the timing of chemotherapy reinitiation after HZ therapy in children with leukemia. The study included 31 children with acute leukemia and HZ infection. General information, clinical symptoms, laboratory test results, duration of HZ treatment, and prognosis were compared with those of children with leukemia alone. Correlation analysis was performed for 20 children who restarted chemotherapy after HZ treatment. Of 31 children with leukemia and HZ, 67.74% had lesions at multiple sites. The median time from chemotherapy initiation to HZ onset was 14.1 (1.5-29.5) months. Among 27 children included in the follow-up, there was one case of HZ relapse. After excluding children who did not continue chemotherapy after HZ treatment, the median interval between completion of HZ therapy and chemotherapy reinitiation in the remaining 20 children was 8.00 (- 3 to 27) days. Lymphocyte counts (LY#) on restarting chemotherapy correlated inversely with HZ lesion healing time (p < 0.05). LY# at the time of HZ onset were lower than those pre- and post-onset, and lower than those in the control group (p < 0.05). In conclusion, children with leukemia have a good HZ prognosis, but an increased risk of HZ recurrence. LY# at the time of chemotherapy reinitiation may be a useful indicator for selecting the optimal interval between antiviral therapy completion and chemotherapy reinitiation.

Casting a wider protective net: Anti-infective vaccine strategies for patients with hematologic malignancy and blood and marrow transplantation

Patients who have hematologic malignancies are at high risk for infections but vaccinations may be effective prophylaxis. The increased infection risk derives from immune defects secondary to malignancy, the classic example being CLL, and chemotherapies and immunotherapy used to treat the malignancies. Therapy of hematologic malignancies is being revolutionized by introduction of novel targeted agents and immunomodulatory medications, improving the survival of patients. At the same time those agents uniquely change the infection risk and response to immunizations. This review will summarize current vaccine recommendations for patients with hematologic malignancies including patients who undergo hematopoietic cell transplant.

Thirteen-Valent Pneumococcal Conjugate Vaccine in Children With Acute Lymphoblastic Leukemia: Protective Immunity Can Be Achieved on Completion of Treatment

BACKGROUND

Children with acute lymphoblastic leukemia (ALL) are at increased risk of developing invasive pneumococcal disease. This study describes the immunogenicity of 13-valent pneumococcal conjugate vaccine (PCV13) during and after chemotherapy.

METHODS

Children with ALL were allocated to study groups and received a single dose of PCV13: group 1, maintenance chemotherapy; group 2, end of chemotherapy; group 3, 6 months after chemotherapy. A protective vaccine response was defined as at least 10 of 12 serotypes (or >83% of serotypes with data) achieving postvaccination serotype-specific immunoglobulin G ≥0.35 µg/mL and ≥4-fold rise, compared to prevaccination at 1 and 12 months.

RESULTS

One hundred eighteen children were recruited. Only 12.8% (5/39; 95% confidence interval [CI], 4.3%-27.4%) of patients vaccinated during maintenance (group 1) achieved a protective response at 1 month postvaccination and none had a protective response at 12 months. For group 2 patients, 59.5% (22/37; 95% CI, 42.1%-75.3%) achieved a response at 1 month and 37.9% (11/29; 95% CI, 20.7%-57.7%) maintained immunity at 12 months. For group 3 patients, 56.8% (21/37; 95% CI, 39.5%-72.9%) achieved a protective response at 1 month and 43.3% (13/30; 95% CI, 25.5%-62.6%) maintained immunity at 12 months.

CONCLUSIONS

This study demonstrated that the earliest time point at which protective immunity can be achieved in children with ALL is on completion of chemotherapy. This is earlier than current recommendations and may improve protection during a period when children are most susceptible to infection.

CLINICAL TRIALS REGISTRATION

EudraCT 2009-011587-11.

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.

Pneumococcal conjugate vaccine administration during therapy for pediatric leukemia

BACKGROUND

Pediatric leukemia patients are at high risk of invasive pneumococcal disease. The study aim was to determine the antibody response to a 10-valent pneumococcal conjugate vaccine (PCV10) administered during chemotherapy.

METHODS

An open-label study in pediatric leukemia patients: Group 1 had completed a primary 7-valent (PCV7) course and received a single PCV10 dose. Group 2 were PCV immunization naïve and received 3 doses of PCV10, administered 2 months apart. Serum samples were taken at baseline and 1 month post each PCV10 dose. Antipneumococcal serotype-specific IgG to 10 serotypes were measured by enzyme-linked immunosorbent assay and the functional response to 4 serotypes (1, 6B, 19F and 23F) was measured using opsonophagocytic assays.

RESULTS

Thirty-nine participants were recruited between May 2010 and January 2011; group 1 (n = 27) and group 2 (n = 12). The diagnosis was acute lymphoblastic leukemia (38) and acute myeloid leukemia (1). Median age was 6.2 years (1.7-17.2 years) with 62% male. The median time from diagnosis to baseline serology was 7.4 months (1.6-36.8 months). At baseline, protective geometric mean concentration above the threshold (>0.35 μg/mL) ranged from 5.3% (serotype 4) to 71% (serotype 19F). More than 60% of participants in both groups were above threshold postimmunization for 7 of the 10 PCV serotypes. Opsonophagocytic assay correlated with enzyme-linked immunosorbent assay for 3 of the 4 serotypes and r ranged from 0.51 to 0.84. An injection-site reaction was reported in 73% (27/37).

CONCLUSIONS

It is safe to administer PCV10 vaccine during therapy for pediatric leukemia. It provided a satisfactory serum immune response for the majority of vaccine serotypes.

Varicella zoster immune status in children treated for acute leukemia

Children treated for acute leukemia are at increased risk of severe infection with varicella zoster virus (VZV). We studied the VZV sero-status of children with acute leukemia prior to starting chemotherapy and after completion of chemotherapy. VZV sero-status was assessed using time resolved fluorescence immunoassay (TRFIA) before starting treatment and 6 months after completion of treatment. Prior to starting treatment for acute leukemia, a significant proportion of children (35%) are VZV seronegative. On completion of treatment most patients maintained protective VZV antibody levels; however, 35% had reduced/loss VZV antibody to a level considered non-protective and susceptible to VZV infection.

Assessment of immune response following immunization with DTP/Td and MMR vaccines in children treated for acute lymphoblastic leukemia

BACKGROUND

This study was performed to determine the antibody titers against diphtheria-tetanus-pertussis, and measles-mumps-rubella before and after re-vaccination in different periods of time in patients with acute lymphoblastic leukemia (ALL) to provide a suitable vaccination schedule.

METHODS

Ninety patients with ALL were studied in three stages, including newly diagnosed patients, patients on maintenance therapy, and 1 to 12 months after cessation of therapy. Baseline antibody titers were assessed in all participants. Postimmunization antibody titers to DTP/Td and MMR vaccines were evaluated 3 weeks after vaccination.

RESULTS

Patients on maintenance therapy had considerable decreased in seropositivity rate; they achieved seroconversion rate of 100% for diphtheria and tetanus and of 71.4% for pertussis following DTP/Td vaccination. In patients after one month off therapy, the seroconversion rates for diphtheria, tetanus, and pertussis were 71.4%, 80%, and 100%, respectively. The amounts of seroconversion in patients after 3 months off therapy were 66.5%, 80%, and 66.5% for measles, mumps, and rubella, respectively. In patients after 6 months off therapy, the seroconversion rates were 85.7% for diphtheria, 100% for pertussis and tetanus, 83.3% for mumps, 50% for rubella, and 41.6% for measles. Patients after 12 months off therapy achieved seroconversion rate of 100% for diphtheria, tetanus, pertussis, and mumps, of 71.5% for rubella, and of 63.5% for measles.

CONCLUSION

Administration of one dosage of DTP/Td vaccine during maintenance therapy and after cessation of therapy could be recommended, while one dosage of MMR vaccine at least three months after completion of therapy could be safe and beneficial.

Revaccination of Children after Completion of Standard Chemotherapy for Acute Leukemia

BACKGROUND

After the treatment of patients with acute leukemia, there is a decrease in vaccine-specific antibody and an increased susceptibility to certain vaccine-preventable diseases. A simple revaccination schedule is warranted.

METHOD

Fifty-nine children (age, 1-18 years) who had completed standard chemotherapy in accordance with Medical Research Council of United Kingdom protocols were recruited. All children received a single dose of Haemophilus influenzae type b (Hib), tetanus, diphtheria, acellular pertussis, meningococcus C, polio, measles, mumps, and rubella vaccines > or = 6 months after completion of treatment. Antibody concentrations were measured before vaccination and 2-4 weeks and 12 months after vaccination.

RESULTS

Prevaccination antibody levels were protective for all patients for tetanus (geometric mean concentration [GMC], 0.13 IU/mL; 95% CI, 0.1-0.17 IU/mL), for 87% for Hib (GMC, 0.5 microg/mL; 95% CI, 0.37-0.74 microg/mL), for 71% for measles (GMC, 301 mIU/mL; 95% CI, 163-557 mIU/mL), for 12% for meningococcus C (geometric mean titer [GMT], 1:2.9; 95% CI, 1:2.2 to 1:3.9), and for 11% for all 3 poliovirus serotypes. Revaccination resulted in a significant increase in levels of antibody to each vaccine antigen, with 100% of patients achieving optimal antitetanus antibody concentrations (defined as > 0.1 IU/mL; 1.5 IU/mL; 95% CI, 1.1-2.1 IU/mL), 93% achieving optimal antibody concentrations to Hib (defined as > 1.0 microg/mL; 6.5 microg/mL; 95% CI, 5.1-8.2 microg/mL), 94% achieving optimal antibody concentrations to measles (defined as > or = 120 mIU/mL; 2720 mIU/mL; 95% CI, 1423-5198 mIU/mL), 96% achieving optimal antibody concentrations to meningococcus C (defined as > or = 1:8; 1:1000; 95% CI, 1:483-1:2064), and 85% achieving optimal antibody concentrations to all the 3 poliovirus serotypes (defined as > or = 1:8). For the majority of subjects, protection persisted for at least 12 months after vaccination.

CONCLUSION

Revaccination of children after standard chemotherapy is important, and protection can be achieved in the majority of these children using a simple schedule of 1 vaccine dose at 6 months after completion of leukemia therapy.