Unexpected protection from infection by two booster hepatitis B virus vaccination in children with acute lymphoblastic leukemia

Seroprevalence of Hepatitis A, B, and C in Syrian Refugee Children Newly Diagnosed With Cancer

Adult survivors of childhood cancer have an increased incidence of hepatitis due to immunosuppression and frequent blood transfusions. The immunization of children with cancer is critical for hepatitis prevention, however, access to vaccination may be restricted during times of war, such as the Syrian armed conflict. The goal of this study was to assess the pretreatment serological status of hepatitis A, B, and C in 48 Syrian refugee children with cancer diagnosed in our center between 2014 and 2021. The control group consisted of 48 Turkish children with cancer who were age, sex, and disease-matched. Fifty-eight boys and 38 girls, with a median age of 4.8 years, were included. There were 42 patients with hematological malignancies, 20 with central nervous tumors, and 34 with other solid tumors. The frequency of hepatitis A seroprevalence was not statistically different between Syrian and Turkish patients, whereas hepatitis B seroprotectivity was found to be significantly lower in Syrian children with cancer than in Turkish children. Two Syrian patients were hepatitis C virus-positive. Thirty-seven percent and 45% of all patients were seronegative for hepatitis B and hepatitis A, respectively. Our findings support the need for hepatitis screening and, if necessary, vaccination of this vulnerable population before chemotherapy.

[Practical management during maintenance therapy of pediatric acute lymphoblastic leukemia: Recommendations of the French Society for Childhood and Adolescent Cancer and Leukemia (SFCE)]

Maintenance therapy is the last phase of treatment for acute lymphoblastic leukemia in children and adolescents. Although maintenance therapy is associated with toxicities and specific management issues, it is an essential phase of treatment that reduces the risk of relapse. The objective of this work is to propose a guide for the initiation, administration, and monitoring of maintenance therapy, and for the management of food, schooling, leisure, community life, risk of infection and links with family medicine.

A Randomized Study Comparing the Efficacy of Three Hepatitis B Vaccine Induction Regimens in Adult Patients with Hematological Malignancies

Objective:

Non-responsiveness to hepatitis B virus (HBV) vaccines is not rare in hemato-oncological patients due to disease-associated or treatment-induced immune suppression. Although different strategies have been employed to improve the response rates, to date there is not an approved schedule for HBV immunization in patients with hematological malignancies. We designed a prospective randomized study to evaluate the efficacy of 3 different induction regimens for HBV vaccination.

Materials and Methods:

In the standard-dose (SD) group, total vaccine dose delivered was 40 µg and patients were vaccinated with 20 µg at weeks 0 and 4. In the high-dose dose-intensive (HDDI) group, total vaccine dose delivered was 80 µg and patients were vaccinated with 40 µg at weeks 0 and 4. In the high-dose time-intensive (HDTI) group, total vaccine dose delivered was 80 µg and patients were vaccinated with 20 µg at weeks 0, 2, 4, and 6.

Results:

In a cohort of 114 patients, 38.6% responded to HBV vaccination. The response rate in the SD arm, HDDI arm, and HDTI arm was 26.2%, 29.7%, and 44.4%, respectively (p>0.05). Age was the only variable identified as having a negative impact on response.

Conclusion:

Short of achieving statistical significance, a higher response rate was observed in the HDTI arm. Therefore, this study supports a high-dose, time-intensive HBV vaccine induction regimen in patients with hematological malignancies who are not on chemotherapy.

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.

Immunization in special populations

In summary, immunizations in special populations require understanding the underlying disease and how it might affect the immune system's ability to mount an antibody response to vaccines or predispose certain patient populations to developing certain serious infections. There is still a great need for research on the optimal timing of vaccines after transplants, how to assess protection and development of a protective antibody response after immunization, and whether certain groups (eg, HIV) need to be revaccinated after a certain amount of time if their antibody levels decline. In addition, there are limited data on efficacy of the newer vaccines in these special patient populations, which also requires further investigation.

Assessment of hepatitis B immunization status after antineoplastic therapy in children with cancer

BACKGROUND AND OBJECTIVES

Hepatitis B is a disease that is preventable with vaccination. Antibody levels after vaccination may be affected by suppression of the immune system due to cancer therapy. Children with cancer have a high risk of hepatitis B virus (HBV) infection. We aimed to assess the pretreatment immunization status against HBV infection and the rate of continuity of immunization after therapy in children with cancer.

DESIGN AND SETTING

Retrospective case review of patients treated from 2004 to 2008.

PATIENTS AND METHODS

We reviewed the medical records of patients treated in the departments of pediatric hematology and oncology and collected data on immunization history and hepatitis B serology. Anti-HBs antibody titers were compared before and after treatment.

RESULTS

This study included 159 (99 males, 60 females) children who had a serologic examination. Antineoplastic therapy had been given for acute leukemia (n=66), non-Hodgkin lymphoma (n=27), Hodgkin lymphoma (n=20), and solid tumors (n=46). Fifty-one patients had not been immunized against HBV prior to the therapy; HBV serology was negative in 49 of these patients and HBsAg was positive in 2 patients. Anti-HBs antibody positivity was present in 99 of 108 patients with an immunization history, whereas no vaccination response was present in 9 patients. The titer of anti-HBs antibody was decreased below the protection level in 33 (33%) patients with positive anti-HBs antibody, whereas the protection level was found to be maintained in 66 (67%) patients. The most significant decrease (63.6%) was observed in leukemia patients. Posttreatment HBsAg and HBV DNA positivity was detected in two of the patients with negative pretreatment serology, whereas no HBV infection developed in the group with positive anti-HBs antibody.

CONCLUSIONS

This study demonstrated the importance of routine childhood vaccination in reducing the risk of HBV infection in patients with cancer.

Vaccinations in children with cancer

Children with cancer may be immunocompromised as a result of their primary underlying disease and/or the use of prolonged and intensive chemotherapy administered with or without irradiation. The damage to the immune system varies with the age of the patient, the type of cancer, and the intensity of the chemotherapy used to treat it. This review analyses the data regarding the immunogenicity, efficacy, safety and tolerability of the vaccines usually recommended in the first years of life in order to help pediatricians choose the best immunisation programme against vaccine-preventable disease in children with cancer receiving standard-dose chemotherapy. Areas for future research are highlighted because new data are required to be able to draw up evidence-based recommendations that will ensure adequate protection against infectious diseases in such high-risk children.