Freed GL, Davis MM, Clark SJ. Variation in Public and Private Supply of Pneumococcal Conjugate Vaccine During a Shortage. JAMA. 2003;289(5):575-578. doi:10.1001/jama.289.5.575
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.
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
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.
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
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.
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
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
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.
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
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
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.