571. How well are Children protected against Vaccine Preventable Diseases after Chemotherapy for Acute Lymphoblastic Leukemia (ALL)?
Session: Oral Abstract Session: Immunization of Children and Adults with Immune Deficiencies
Thursday, October 3, 2013: 2:15 PM
Room: The Moscone Center: 250-262
Background:

Immunization recommendations for children treated for cancer are based on expert opinion due to the paucity of evidence-based data. The objective of this study was to assess the level of protection against vaccine-preventable diseases (VPD) in children treated for ALL.

Methods:

Clinical characteristics and immunization records of the children who completed the COG chemotherapy Boston protocol for ALL between 2000 to 2012 at our institution, were collected. Family members’ vaccination records were reviewed. Antibody titers before revaccination were measured after completion of chemotherapy. Level of protection was determinate in accordance with thresholds defined by the WHO. Polio antibodies were obtained by neutralisation with vaccine strains from our National Microbiology Laboratory. Enzyme immunoassays were used to determine the remaining antibodies.

Results:

36 children (50% girls) with a median age of 4 years (0-16) at the diagnosis of ALL, were included. Among them, 32 (88%) were up to date with their vaccination schedules prior to the start of chemotherapy. Antibody titers were measured 13 months (1-147) after the end of chemotherapy.  The percentage of children who did not achieve protective antibody levels to specific pathogens is summarized in table 1. Among the 20 patients who had completed chemotherapy for more than 12 months (median time since completion 2.9 years), 11 (55%) had not received any vaccine and none had had a complete catch-up immunization series. Only 8% of the parents were up to date with their immunization schedules. Noteworthy, only 50% of the parents and 43% of the siblings had received yearly seasonal influenza vaccine.

 

Table 1: Percentage of non protected children against VPD after chemotherapy

VPD

Measles

Rubella

Mumps

Varicella

Diphteria

Tetanus

Hib

Polio

1

2

3

Protective threshold

> 1,1 ISR

> 1,1 ISR

> 0,2  ISR

> 1,1 ISR

≥ 0.1 UI/ml

≥ 0.1 UI/ml

≥ 1 mg/L

≥ 1/8

non protected n, (%)

11(33%)

11(35%)

22(29%)

14(41%)

17(41%)

14(48%)

21(63%)

8(31%)

10(38%)

12(46%)

ISR = immune status ratio

Conclusion:

Children after chemotherapy for ALL are not adequately immunized and protection achieved against VPD is suboptimal. Our data supports the need for a systematic booster vaccination after chemotherapy. Immunization practices in the family should also be enhanced.


Isabel Garcia De La Fuente, MD MSc1, Léna Coic, MD1, Jean-Marie Leclerc, MD2, Caroline Laverdière, MD2, Denis Blais, MSn1, Céline Rousseau, MD3, Philippe Ovetchkine, MD MSc1 and Bruce Tapiero, MD1, (1)Department of Pediatrics, Division of Infectious Diseases, CHU Sainte-Justine – University of Montreal, Montreal, QC, Canada, (2)Department of Pediatrics, Division of Onco-Hematology, CHU Sainte Justine, University of Montreal, Montreal, QC, Canada, (3)Department of Microbiology and Immunology, CHU Sainte-Justine – University of Montreal, Montreal, QC, Canada

Disclosures:

I. Garcia De La Fuente, None

L. Coic, None

J. M. Leclerc, None

C. Laverdière, None

D. Blais, None

C. Rousseau, None

P. Ovetchkine, None

B. Tapiero, None

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