An analysis of the pediatric vaccine supply shortage problem

Abstract

In 2002, several factors resulted in pediatric vaccine manufacturers not being able to produce a sufficient number of vaccines to vaccinate all the children in the United States according to the Recommended Childhood Immunization Schedule. The resulting vaccine supply shortage resulted in thousands of children not being fully immunized according to this schedule, and hence, created an unnecessary risk for epidemic outbreaks of several childhood diseases. The Centers for Disease Control and Prevention responded to this crisis by using pediatric vaccine stockpiles to mitigate the impact of future shortages. This paper presents a stochastic model that captures the vaccine supply during production interruptions. This model is used to assess the impact of pediatric vaccine stockpile levels on vaccination coverage rates, by considering the probability that all children can be immunized according to the Recommended Childhood Immunization Schedule over a given time period and the expected minimum vaccine supply. The model is also used to assess the proposed pediatric vaccine stockpile levels recommended by the United States Department of Health and Human Services. The results of this analysis suggest that the proposed vaccine stockpile levels are adequate to meet future vaccine production interruptions, provided that such production interruptions do not last more than six months (which is not surprising, given that is the time period for which they were designed). However, given that recent vaccine production interruptions have lasted (on average) for over one year, the proposed vaccine stockpile levels are insufficient to meet the nation's pediatric immunization needs during such time periods, which in turn could lead to localized and/or widespread disease outbreaks. Moreover, a moderate investment in higher vaccine stockpile levels would lead to a significantly reduced risk of such events.

Framework for Optimal Global Vaccine Stockpile Design for Vaccine‐Preventable Diseases: Application to Measles and Cholera Vaccines as Contrasting Examples

“…The United States maintains relatively constant annual vaccine demand, and after experiencing numerous vaccine shortages, the United States created a pediatric vaccine stockpile in 1983, which the 1993 Omnibus Reconciliation Act funded through the Vaccines for Children Program to ensure access to a six‐month supply of all vaccines in the recommended routine immunization pediatric schedule . Prior studies related to optimizing the U.S. pediatric vaccine stockpile used (1) a stochastic inventory model to explore the adequacy of a six‐month supply, with the length of a production downtime considered as the primary uncertainty; (2) a static model to estimate the potential health and financial costs associated with vaccine shortages for different stockpile sizes assuming that missed children do not get caught up; and (3) a multiattribute approach to optimizing the opportunities to use vaccine supplies to increase immunization coverage . The last of these assumed that the U.S. public health authorities wish to increase coverage up to the point that the population benefits from herd immunity and no further.…”

“…We build on the framework that we previously developed for the planned global stockpile for oral polio vaccines (OPVs), which will exist for a short time to facilitate rapid response to any potential poliovirus outbreaks that might occur soon after coordinated cessation of OPV use following the eradication of wild polioviruses . In contrast to existing U.S. stockpile models, we focus our conceptual framework on fully dynamic vaccine stockpiles that consider the changing levels of population immunity using transmission models that track infections, and we explore what it would mean to maximize the expected utility of vaccine stockpiles for different potential objectives considering both health and financial costs. Analysts must use dynamic models of transmission to appropriately capture the economic benefits of many vaccines .…”

Maximizing the effectiveness of a pediatric vaccine formulary while prohibiting extraimmunization

“…There are several articles in the literature that report research that applies operations research techniques to pediatric immunization problems (e.g., [20][21][22][24][25][26]). This paper moves in a new direction by applying discrete optimization techniques to address the issue of pediatric vaccine extraimmunization.…”

“…Moreover, the economic toll of extraimmunization is also significant. For example, the annual societal cost burden of providing one extra dose of vaccine for each child born in the United States is no less than $28 million, which assumes a birth rate of 11,100 births per day (see [26]) and a vaccine cost of $7, where the vaccine cost estimates the Federal contract purchase price of the least expensive pediatric vaccine (see [3]). …”

“…The objective of this IP was to aide decision-makers in determining the vaccine formulary that minimized the cost to fully immunize a child. Jacobson et al [26] present a more rigorous presentation of this pilot study and demonstrate how the model selects different vaccine formularies depending on the desired economic criteria. Sewell et al [30] embed the IP from the pilot study into a bisection algorithm [2] to "reverse engineer" the maximum inclusion prices (the maximum price at which a vaccine remains part of the optimal vaccine formulary) of four combination vaccines not yet (at that time) licensed in the United States.…”