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Sole supply of influenza vaccine: economic common sense or a
disaster waiting to happen?
Tim Blackmore
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Abstract
The interruption to the New Zealand influenza vaccine
supply in 2005 (caused by a manufacturing error) greatly disrupted the annual
influenza vaccination programme. The sole-tendering process used by PHARMAC was
blamed by some for the crisis, which may have been alleviated by having more
than one supplier. In this article, the author discusses the issues resulting
from having limited options of vaccine supply. Supply problems are not limited
to influenza vaccine but the tight timelines required for vaccine delivery may
make it wise to secure two suppliers in future. Like all health insurance, the
cost of supply redundancy will be appreciable.
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Vaccine:
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Influenza vaccine.
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Indication:
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Prevention of influenza.
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Recommended
dose & duration:
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Single intramuscular (IM) dose for immunocompetent adults,
and two doses (1 month apart) for children or the immunocompromised.
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Clinical
efficacy:
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70–90% protective efficacy in healthy adults for
matched strains.1
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Background:
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Disease due to influenza virus covers a spectrum from mild
to extremely severe. Whilst influenza classically is associated with sudden
onset of fever, myalgia, and cough, it also can be indistinguishable from the
common cold.2 Influenza is an important cause
of morbidity and mortality, and is often
under-recognised.3
The greatest rates of influenza occur during the winter
months from May to October, with a peak period lasting around 10
weeks.4 Influenza is a highly infectious
disease and spreads rapidly through long-term care facilities, hospitals, and
schools. The greatest mortality from influenza is generally reported to occur in
the elderly and those with pre-existing morbidity, and so influenza vaccine is
recommended and funded by the Government for those
groups.1
Influenza vaccine contains three strains of killed whole
virus: two A strains and one B. Each year, the World Health Organization (WHO)
and regional experts meet with vaccine-producing companies to select which viral
strains will be included for the Southern Hemisphere winter. The variation in
vaccine make-up each year makes for tight manufacturing and delivery
timelines.
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Government
policy:
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The Ministry of Health (MOH)
actively recommends influenza vaccine, and provides it free of charge to all
patients over the age of 65 and to most groups under the age of 65 who also have
pre-existing chronic medical conditions.
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Current
situation:
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New Zealand:
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There is currently an over-supply of influenza vaccine,
because extra doses were imported from a number of vaccine suppliers. This
situation arose because the Vaxigrip influenza vaccine supplied by
Sanofi-Pasteur was found by Australian regulators to have only 10μg of
A/Wellington (H3N2) rather than the 15μg required in the licensing
specification.
Alternative supplies of full-dose vaccine were located from
other suppliers until the immunogenicity and efficacy of the lower-dose vaccine
was established. Ultimately, the lower-dose vaccine was found to be immunogenic
in immunocompetent adults, and was released into the
market.5
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Economic
analysis:
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New Zealand (NZ) is only a small market, and although over
700,000 doses of influenza vaccine are ordered each year, using more than one
supplier will (in all probability) increase the cost per dose. Splitting the
tenders may also result in vaccine manufacturers providing less support or
commitment to the NZ market.
It has been argued that sole supply in the vaccine market is
not necessarily a bad thing for a variety of economic arguments. In particular,
there may be economic advantages to arranging redundancy of supply and
contingency planning from one manufacturer rather than contracting two or more
suppliers.6
Moreover, it would be necessary to over order to ensure that
sufficient number of doses are available to those at greatest need if one
supplier could not deliver on time. Even with two suppliers there would still be
problems with prioritising who would receive the vaccine in the event of one
vaccine delivery failure.
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Other
issues:
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It was asserted in the media, and elsewhere, that PHARMAC
precipitated the crisis by contracting only a single supplier through its tender
process.7 Was this wise financial management or
exposing the NZ population to avoidable risk?
Firstly, it is important to realise that there are only a
limited number of vaccine manufacturers, and some vaccines, such as the
pneumococcal conjugate vaccine, are made by only one company.
Secondly, vaccines have a short shelf life, and require
special storage and transport facilities. It is therefore not surprising that
there have been numerous examples from around the world of supply disruption,
including MMR and varicella vaccines from Merck, influenza vaccine from Chiron,
and DTaP from Sanofi-Pasteur. A problem with even one batch can affect vaccine
supply in several countries.
New Zealand has had a single influenza vaccine supplier for
the past few years. The fact that PHARMAC took over the process this year, and
this was associated with quality problems was an unfortunate
coincidence.
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Comment:
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The real question now is whether influenza and other
vaccination programmes should rely on one supplier to the NZ market. The
experience from this year would suggest that extra cost to the Government of
securing redundancy of supply may be worthwhile. To be useful, there would need
to be sufficient doses to cover all high-risk individuals twice.
It is almost inevitable that
vaccine supplies will be disrupted again in the future, but whether one major
incident is sufficient to trigger a very expensive insurance policy is the stuff
of health politics rather than simplistic answers. As an arm of Government,
PHARMAC may have to find a compromise between finding the lowest cost per
vaccine delivered and providing contingency planning against future supply
disruptions.
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Author information:
Tim Blackmore, Infectious Diseases Physician and Microbiologist, Capital
and Coast DHB and Institute of Environmental Science and Research,
Wellington
Correspondence: Tim
Blackmore, Infectious Diseases Physician and Microbiologist, Laboratories,
Wellington Hospital, PO Box 7902, Wellington. Email: tblackmore@paradise.net.nz
References:
- Ministry
of Health. The NZ Immunisation Handbook 2002. Available online. URL: http://www.moh.govt.nz/moh.nsf/ea6005dc347e7bd44c2566a40079ae6f/17b9ed43b23631d3cc256b52000a00e2/$FILE/ImmunisationChapter13.pdf
Accessed July 2005.
- Call
SA, Vollenweider MA, Hornung CA, et al. Does this patient have influenza? JAMA.
2005;293:987–97.
- Surveillance
for laboratory-confirmed, influenza-associated hospitalizations—Colorado,
2004–05 influenza season. MMWR. 2005;54:535–7.
- Lopez
L, Huang S. Influenza in New Zealand – 2004. Porirua: ESR. Available
online. URL: http://www.surv.esr.cri.nz/PDF_surveillance/Virology/FluAnnRpt/InfluenzaAnn2004.pdf
Accessed July 2005.
- Ministry
of Health. Media release. Medsafe removes restrictions on Vaxigrip vaccine.
Available online. URL: http://www.moh.govt.nz/moh.nsf/0/F53574F6FBEE5272CC256FF8001D2F21?Open
Accessed July 2005.
- Danzon
P, Pereira NS. Why sole supplier vaccine markets may be here to stay. Health
Affairs 2005;24:694–6.
- Speech
to the Research Medicines Industry Conference. Cystic Fibrosis Association of
New Zealand (CFNZ) Forum Discussion; 2005. Available online. URL: http://www.cfnz.org.nz/forum/viewtopic.php?t=83
Accessed July 2005.
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