Evaluation of rotavirus vaccine administration among a 22q11.2DS patient population

Area of Science:

• Pediatric Immunology
• Clinical Genetics
• Vaccinology

Background:

• 22q11.2 Deletion Syndrome (22q11.2DS) is associated with immune dysfunction, necessitating pre-vaccination immune evaluation.
• International guidelines mandate immunological assessment for 22q11.2DS patients before live vaccine administration.
• A rotavirus vaccination program in British Columbia (BC) began in 2012, raising questions about adherence to pre-vaccination immune workup for infants with 22q11.2DS.

Purpose of the Study:

• To evaluate adherence to international guidelines for immune workup in infants with 22q11.2DS prior to rotavirus vaccination in BC.
• To identify the incidence of adverse events following immunization in this cohort.
• To assess the timeliness of immunological assessment relative to rotavirus vaccine administration.

Main Methods:

• A retrospective chart review was conducted for children diagnosed with 22q11.2DS in BC between 2012 and 2019.
• Data collected included demographics, clinical information, laboratory results, immunization status, and adverse reactions.
• Adherence to recommendations was assessed against international guidelines for immunological workup.

Main Results:

• Of 42 children with 22q11.2DS, 22 (52.3%) received at least one dose of rotavirus vaccine; no adverse events were reported.
• While 92.6% of those with an immune workup had adequate CD4+ counts, only 44% received the vaccine.
• Only 45.5% of infants diagnosed before 8 weeks of age received an immune workup before their first rotavirus vaccine dose.

Conclusions:

• The majority of infants with 22q11.2DS in BC did not receive care aligned with international vaccination and immunological surveillance guidelines.
• There is a critical need for better dissemination of 22q11.2DS guidelines to healthcare providers.
• Improved and timely immunological assessment for infants with 22q11.2DS is essential for safe vaccination practices.