Perez EE, Bokszczanin A, McDonald-McGinn D, Zackai EH, Sullivan KE. Pediatrics. 2003;112:e325–e327
Purpose of the Study.
To investigate the incidence of side effects after live viral vaccine administration in a population with chromosome 22q11.2 deletion syndrome.
A total of 174 patients with chromosome 22q11.2 deletions were evaluated at Children’s Hospital of Philadelphia between 1994 and 2002. Of these, 59 patients completed a questionnaire regarding live viral vaccination; these constituted the study population.
Patient records were reviewed retrospectively. Data acquisition was designed to record the clinical consequences of vaccination or of withholding the vaccines.
Thirty-two patients received varicella vaccine. Of those, 3 (9%) reported mild adverse events (fever alone). Vaccinated patients did not contract wild-type varicella, whereas 63% of unvaccinated patients did. Unvaccinated patients had lower T cell numbers, presumably because vaccine was withheld because of theoretical concerns regarding safety. Despite this, no patient who developed chicken pox required hospitalization. Fifty-two patients received measles-mumps-rubella vaccine. Of those, 12 (23%) reported mild adverse reactions, consisting of fever, rash, and malaise. None of the unvaccinated patients developed wild-type measles, mumps, or rubella infection. For neither varicella vaccine nor measles-mumps-rubella vaccine were T cell counts correlated with the occurrence of adverse effects.
Adverse reactions to common, live, attenuated, viral vaccines among patients with 22q11.2 deletions were similar in frequency and severity to those in the general population. Varicella vaccine appeared to be very protective in this population.
As the authors noted, this study was limited by size, by its retrospective nature, by comparison with the general population, and by relying on parental recollection of adverse events. Also, T cell counts at the time of immunization were not available for many patients, because the diagnosis was not yet established. However, this analysis provides a very reasonable basis for the general safety and efficacy of these vaccines among patients with 22q11.2 deletions and lays the groundwork for a more definitive prospective study.