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Table 1. Proportion of Practices With at Least 1 Out-of-Stock Episode
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Table 2. Cumulative Duration of Out-of-Stock Episodes
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Table 3. Relationship Between PCV7 Use and Cumulative Out-of-Stock Duration
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1.
Centers for Disease Control and Prevention.  Decreased availability of pneumococcal conjugate vaccine.  MMWR Morb Mortal Wkly Rep.2001;50:783-784. Taken from: JAMA. 2001;286:2232.
2.
Freed GL, Clark SJ, Cowan AE. State-level perspectives on immunization policies, practices, and program financing in the 1990s.  Am J Prev Med.2000;19:32-44.
3.
Clements DA, Zaref JI, Bland CL, Walter EB, Coplan PM. Partial uptake of varicella vaccine and the epidemiological effects of varicella disease in 11 day-care centers in North Carolina.  Arch Pediatr Adolesc Med.2001;155:455-461.
4.
Orenstein WA, Hinman AR, and Rodewald LE. Public health considerations—United States. In: Plotkin SA, Orenstein WA, eds. Vaccines. 3rd ed. Philadelphia, Pa: WB Saunders; 1999.
5.
Wood D, Schuster M, Donald-Sherbourne C, Duan N, Mazel R, Halfon N. Reducing missed opportunities to vaccinate during child health visits.  Arch Pediatr Adolesc Med.1998;152:238-243.
6.
Davis MM, Andreae MA, Freed GL. Physicians' early challenges related to the pneumococcal conjugate vaccine.  Ambul Pediatr.2001;1:302-305.
7.
Institute of Medicine.  Calling the Shots: Report of the Committee on Immunization Finance Policies and PracticesWashington, DC: National Academy Press; 2000.
Brief Report
February 5, 2003

Variation in Public and Private Supply of Pneumococcal Conjugate Vaccine During a Shortage

Author Affiliations

Author Affiliations: Child Health Evaluation and Research Unit, Division of General Pediatrics (Drs Freed and Davis and Ms Clark), and Division of General Internal Medicine (Dr Davis), University of Michigan, Ann Arbor.

JAMA. 2003;289(5):575-578. doi:10.1001/jama.289.5.575
Context

Context In late August 2001, a serious shortage of the heptavalent pneumococcal conjugate vaccine (PCV7) developed in 34 state immunization programs. In September 2001, the Centers for Disease Control and Prevention published revised recommendations advising physicians to prioritize PCV7 to specific groups of children. The effect of the shortage at the practice level is unknown.

Objective To determine the variation between public and private markets in the supply of PCV7 and the nature and extent of the PCV7 shortage at the practice level.

Design, Setting, and Participants Semistructured interviews with office staff responsible for ordering vaccines at private practices in 12 states were conducted between October 19 and November 2, 2001.

Main Outcome Measures Variation in supply of PCV7 obtained from public sources and through purchase on the private market. Supply was characterized into 3 categories: "no problem," "problem obtaining a consistent supply," and "out of stock."

Results Interviews were completed at 405 practices, representing a response rate of 74%. Overall, 51% of practices reported at least 1 episode of being out of stock of public PCV7 and 64% of private PCV7, with significant state-to-state variation. Only 2 of 12 study states had a substantially higher proportion of practices experiencing out-of-stock episodes for public compared with private PCV7, while in 6 states public PCV7 was less frequently out of stock than private PCV7. Only 23% of practices in this study altered their administration policy for private PCV7, while 27% altered their policy for public PCV7.

Conclusions The distribution and supply of PCV7 varied between public and private supplies and between states during the shortage. Few practices changed their administration schedules in response to revised recommendations.

In August 2001, approximately 1 year after heptavalent pneumococcal conjugate vaccine (PCV7) was recommended for universal administration to all children younger than 2 years in the United States, state- and practice-level shortages of the vaccine in both the public and private markets developed. In September 2001, the Centers for Disease Control and Prevention (CDC) published revised recommendations for PCV7, advising physicians to prioritize administration to children who had received only 1 dose or had never received the vaccine.1 Some states also promulgated their own revised recommendations.

Vaccines are obtained by physicians from public or private supplies. Almost all publicly funded vaccine is purchased via the federal Vaccines for Children (VFC) program, which provides funding for vaccines for all children who are Medicaid enrolled, uninsured, Alaska natives, or Native Americans. Federally qualified health centers can also administer VFC vaccine to underinsured children. Practices obtain vaccine for privately insured children from the manufacturer or a distributor. It is unknown whether the PCV7 shortage was more problematic for children receiving publicly funded vaccine or for children with private insurance coverage.

When PCV7 shortages became apparent, it was unclear which factors were related to shortages at the practice level, where shortages ultimately affect health care. Furthermore, it was unknown if health care practitioners actually changed their practice of administering PCV7 because of the shortage, either on their own or in response to officials' revised recommendations. Therefore, we designed a multistate study to determine the nature and extent of the PCV7 shortage at the practice level.

METHODS

The study involved semistructured interviews with office staff responsible for ordering vaccines at private practices in 12 states. These states were selected based on state vaccine financing strategy and geographic distribution.2 Because the study was investigating variation between public and private markets in the PCV7 supply, the 14 states with a universal vaccine purchase program were excluded. In such states, vaccine for all children is purchased with public sector funds and distributed free to all health care practitioners.2 As such, no difference in the public vs private supply of vaccine in individual practices would be expected. The states included in the study were California, Florida, Kansas, Kentucky, Louisiana, Maryland, Michigan, New York, Oregon, Pennsylvania, Texas, and Wisconsin.

From lists of VFC-participating practices in the study states, we excluded all public clinics, school- or prison-based clinics, and hospitals. Of the remaining private practices, 35 to 66 practices per state were selected to represent all geographic regions of the states, as well as urban, suburban, and rural locations.

For each practice, an introductory letter was faxed to the contact person named on the VFC participant list, explaining the purpose of the study and indicating that someone from the study team would telephone them to conduct an interview. A semistructured interview protocol was developed to ensure standardized collection of data. Interviewers were trained to verify responses and probe for clarification and detail, particularly chronology. Specific questions involved the role of the interviewee in vaccine ordering and administration; PCV7 ordering patterns, usage, changes in administration policies, and supply problems for public and private supplies; and the sources and content of information the practices received regarding the PCV7 shortage. Interviews were conducted between October 19 and November 2, 2001; the study period was limited to 2 weeks to ensure comparability between responses with regard to timing and duration of PCV7 supply problems. Interview length typically was 10 minutes and ranged from 3 to 40 minutes.

Completed interview forms were reviewed and coded by 1 of the investigators (S.J.C.). Data were analyzed using SAS software, version 6.12 (SAS Institute Inc, Cary, NC). We distinguished between PCV7 obtained from public sources and through purchase in the private market. For purposes of analysis, we characterized problems with supply into 3 categories: "no problem," "problem obtaining a consistent supply," and "out of stock." Frequency distributions were calculated for all practices and for each state. χ2 Analyses were used to evaluate the statistical significance of associations between PCV7 volume and timing/duration of practices being out of stock of the vaccine.

The research project was approved by the University of Michigan Medical School Institutional Review Board, Ann Arbor.

RESULTS

Of the 589 practices selected for the study, 41 were categorized as ineligible because the practice had closed or PCV7 was not offered routinely. Of the remaining 548 eligible practices, 16 refused to participate and 127 could not be scheduled during the 2-week study period. The 405 completed interviews represent an overall response rate of 74%, ranging from 54% to 82% by state. Most interviews (84%) were conducted with nurses or other clinical personnel involved in both ordering and administration of vaccines.

Overall, 80% of practices reported problems obtaining a consistent supply of private PCV7, while 70% reported inconsistencies with their public supply. At some point in 2001, 51% of practices reported at least 1 episode of being out of stock of public PCV7 and 64% of private PCV7. State variation was evident for public vs private PCV7 supply (Table 1). Only 2 of 12 study states had a substantially higher proportion of practices experiencing out-of-stock episodes for public compared with private PCV7, while in 6 states public PCV7 was less frequently out of stock than private PCV7.

Considerable variation occurred across states in the total time out of stock, cumulative for all episodes, for private or public PCV7 (Table 2). More than half of practices in 10 states experienced an out-of-stock duration of at least 1 week for private PCV7 and in 6 states for public PCV7. In contrast, a smaller proportion of practices reported a cumulative out-of-stock duration of at least 2 months. Five states had a substantially higher percentage of private (vs public) out-of-stock duration for at least 2 months; in 3 states, the proportion out of stock for public PCV7 for at least 2 months was higher. Many interviewees reported that during their initial days out of stock, they borrowed from the practice's private (or public) supply to ensure that children would be vaccinated. As the time out of stock extended beyond 1 week, such borrowing could not continue without compromising the other stock, causing financial burden, or complicating record keeping.

Estimated monthly use of both private and public PCV7 varied among the practices; 32% had monthly use of 100 or more doses of private PCV7, while only 17% had monthly use of at least 100 doses of public PCV7. With increasing monthly use of private PCV7, the likelihood of being out of stock ever and for at least 1 week increased (Table 3). For public PCV7, a similar pattern was observed. Practices with higher estimated monthly use also had a trend toward a higher proportion of being out of stock for at least 1 month.

Only 23% of practices altered their administration policy for private PCV7 and 27% for public PCV7 because of PCV7 supply problems. The most common changes were prioritizing the first and second doses of PCV7 and limiting PCV7 vaccination to high-risk children only. However, more than half of the respondents from practices that experienced PCV7 supply problems indicated that they were unaware of a national shortage until their own practice was affected. At that point, they had little or no PCV7 in stock and it was too late to implement any efforts to prioritize vaccination.

COMMENT

The PCV7 shortage highlights the complexity in the current system of vaccine purchase and distribution in the United States. Most primary care physicians maintain both public and private supplies of vaccine. However, a given child may receive vaccine from either the public or private supplies but not both. Thus, consequences of a disruption of vaccine supply may pertain to the entire population of children or only specific groups based on insurance status.

Our findings demonstrate variability in the distribution and supply of a specific vaccine during a shortage situation. This variability occurred in many domains, including differences between public and private supplies and among states. For some states, the shortages of PCV7 were more commonly observed in the private supply of vaccine; in others, the public supply was more tenuous. Shortage patterns appeared to be independent of specific regions of the country. Reasons given by the manufacturer for the shortage of PCV7 have included greater-than-expected demand for the vaccine, problems with production, and a prolonged US Food and Drug Administration approval process of each lot of vaccine. Other new vaccines did not achieve a similar rate of uptake,3 and the high level of demand exceeded manufacturer expectations and production plans.

Vaccine manufacturers have competing priorities in determining supply to the public or private markets in times of shortage. More than half of all vaccines for children purchased in the United States are bought in the public market.4 For most vaccines, federal contracts provide for purchase at a discounted price relative to the private market.4 This creates a financial incentive for manufacturers to ensure adequate supply to the private market, where prices are higher. However, in return for the ability to enter the large government purchase market, manufacturers are obligated to meet specific minimum supplies to the public sector. Our findings indicate that there was no concerted effort on the part of the manufacturer to shunt vaccine to either the public or private marketplace. Future contract negotiations between the federal government and the vaccine manufacturers should contain safeguards to ensure adequate public vaccine supply.

The variation in the public sector shortage among states was at least partially due to the initial supplies of PCV7 in each state. Although states order their public supply of PCV7 vaccine on a regular basis from the CDC, the amount of inventory maintained by a given state varies depending on order frequency, inventory management procedures, distribution policies, and percentage of budget allocated to maintaining vaccine supply. Greater guidance from the CDC to state immunization program managers in these areas may be helpful to minimize the variability among states in the supply of public vaccine.

The state-to-state variation in private supplies is likely a function of the distribution network used by the manufacturer and nuances of their marketing efforts. In some markets, the manufacturer ships vaccine directly to practices. In other markets, third-party distributors are used.

The variable nature of the PCV7 shortage in the public and private supplies of vaccine was a source of frustration to health care practitioners. Although practitioners indicated that they are accustomed to dealing with vaccine shortages of limited duration by "borrowing" from one stock (public or private) to cover the other, a shortage of longer duration was problematic. Practices that were able to obtain only private supplies of PCV7 were unable to afford long-term use of their privately purchased vaccine for VFC-eligible children. Practices able to obtain only public PCV7 were often in states with regulations prohibiting the use of public vaccine for non–VFC-eligible children. In several practices, there simply was not sufficient vaccine for borrowing to occur. The result was a 2-tiered system of PCV7 provision, where in a single practice site some children could receive vaccine but not others.

The prolonged shortage of PCV7 also has added a new dimension to the concept of "missed opportunities" for immunization.5 Immunization rates within practices increasingly are used as a mechanism to measure quality. Practices that have a limited supply of a vaccine will have lower immunization rates despite their best attempts to immunize all children. Furthermore, these missed opportunities will be more complex to track and remedy when vaccine supply varies between public and private sources. It is also unclear if "catch-up" immunization programs will be effective for large populations of children who have not received PCV7 vaccine or practical for many practices and parents.

The PCV7 shortage may affect future decisions by physicians in private practice to incorporate new vaccine recommendations into their immunization routines. Physicians promoted this vaccine to parents and aggressively sought insurance coverage soon after it was recommended.6 They were then placed in the difficult position of not being able to supply a vaccine they had recommended. As a result, physicians may be less willing to adopt new vaccines until an adequate vaccine supply in both the public and private markets is firmly established.

One strategy used by the CDC to address the shortage was to revise the initial recommendation for PCV7 vaccine.1 However, our study indicates that few practices changed their schedules for administration of PCV7. Most practices had already run out of PCV7 before the change in recommendation was made. Others were placed in the uncomfortable position of changing their immunization practices to exclude groups of children previously recommended to receive the vaccine. It is unclear whether the revised CDC recommendation for PCV7 will prove effective in avoiding potential liability for health care practitioners who are unable to administer recommended vaccines due to shortages.

This study was conducted during a limited period early in the course of the PCV7 shortage. As the shortage has continued, it is possible that management of the shortage within given practices also evolved. However, this study is the first, to our knowledge, to describe the manner in which practices experienced shortages of different vaccine supplies.

The information collected relied on the self-report of practices and was not verified by checking actual ordering patterns. To ensure the greatest potential accuracy of data, we interviewed those whom each practice identified as responsible for the ordering and maintenance of vaccine supply.

The current vaccine purchase and supply system in the United States is a complex patchwork of public and private markets. Government programs enacted during the past decade have resulted in a large cadre of children depending on adequate vaccine purchase in the public sector to ensure opportunities for immunization.7 Similar reliance for privately insured children exists in the private marketplace. Disruptions of vaccine supply can affect either or both of these populations, who are frequently served by the same physicians. Therefore, future public policy debate regarding vaccine supply must incorporate the processes, needs, and perspectives of the public and private sectors.

References
1.
Centers for Disease Control and Prevention.  Decreased availability of pneumococcal conjugate vaccine.  MMWR Morb Mortal Wkly Rep.2001;50:783-784. Taken from: JAMA. 2001;286:2232.
2.
Freed GL, Clark SJ, Cowan AE. State-level perspectives on immunization policies, practices, and program financing in the 1990s.  Am J Prev Med.2000;19:32-44.
3.
Clements DA, Zaref JI, Bland CL, Walter EB, Coplan PM. Partial uptake of varicella vaccine and the epidemiological effects of varicella disease in 11 day-care centers in North Carolina.  Arch Pediatr Adolesc Med.2001;155:455-461.
4.
Orenstein WA, Hinman AR, and Rodewald LE. Public health considerations—United States. In: Plotkin SA, Orenstein WA, eds. Vaccines. 3rd ed. Philadelphia, Pa: WB Saunders; 1999.
5.
Wood D, Schuster M, Donald-Sherbourne C, Duan N, Mazel R, Halfon N. Reducing missed opportunities to vaccinate during child health visits.  Arch Pediatr Adolesc Med.1998;152:238-243.
6.
Davis MM, Andreae MA, Freed GL. Physicians' early challenges related to the pneumococcal conjugate vaccine.  Ambul Pediatr.2001;1:302-305.
7.
Institute of Medicine.  Calling the Shots: Report of the Committee on Immunization Finance Policies and PracticesWashington, DC: National Academy Press; 2000.
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