Revaccination management of a large cohort of pediatric patients following a potential lapse in cold storage.

Introduction: In a pediatric clinic in California (US), 3823 patients were vaccinated with potentially-compromised vaccines following lapses in cold storage chain management between February 2014 and April 2015. A revaccination program was initiated in May 2015. Families were contacted by mail and encouraged to discuss follow-up options with their care team, namely: revaccination, serological testing and/or revaccination, or no further action. This study aimed: to understand which families were more likely to respond to the outreach, and to engage in any testing and/or revaccination; to determine whether or not vaccination with these potentially-compromised vaccines elicited sufficient immune response in pediatric patients; and to estimate the program cost.
Methods: Patients who had received potentially-compromised vaccines were identified, and relevant data were extracted from their electronic health records. Logistic regression analyses were performed to identify factors associated with response to outreach, serological testing and/or revaccination.
Results: 3823 patients between 0 and 21 years received an average of 3.1 potentially-compromised vaccines. 2547 revaccinations were performed (1515 patients) and 544 patients had serological testing results. Non-immune titer levels were only reported for 3-4% and 8% of the tested patients who had received potentially-compromised tetanus and hepatitis B vaccines, respectively, and only for children two years old and younger. Three years after the revaccination program started, 77% of all cases were considered resolved and 62.5% of patients (1970/3152) who were administered potentially-compromised vaccines were either revaccinated or had seroprotective titers. Response to outreach and decision to choose serological testing and/or revaccinate were affected by patient age, race/ethnicity and zip code median income (p < 0.05).
Conclusion: We observed race/ethnicity, patient age and income differences in response to the outreach and decision-making. For patients vaccinated with potentially-compromised vaccines, serological testing should be considered prior to revaccination. Revaccination may not be the most appropriate course of action for all patients.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)