Memorandum by Dr R L Salmon, Director,
Communicable Disease Surveillance Centre, National Public Health
Service for Wales
1. The submission is substantially confined
to the Sub-Committee's particular questions. The views expressed
are my own and based on 15 years as a regional epidemiologist
in Wales, including some published research on the impact of the
1989 epidemic in Wales.
How is the risk of pandemic influenza emerging
in south east Asia, and reaching the UK, being assessed; and how
can this assessment be improved?
2. It seems inconceivable that there will
not be another influenza pandemic, given that they have occurred
throughout recorded history. How soon it will occur and whether
H5N1 Avian influenza strains, circulating currently in the far
east, will constitute the next human pandemic strain is very uncertain
and could be said to represent a (well) educated guess. Nevertheless,
sufficient authoritiative scientific authorities on influenza
regard this to be of concern, that it would be unwise not to bring
forward measures for influenza pandemic planning that are themselves
3. Assessment might potentially be improved
by harnessing a combination of molecular biological and information
technology techniques. The ability of an influenza virus to infect
a host (although not its subsequent virulence) is determined by
the extent to which its haemagluttinin is adapted to bind with
that host's cell's sialic acid receptors. Much is known both about
the differences in haemagluttinin structure between avian adapted
and human adapted strains and about the influenza genome and how
these differences are coded for. This could permit an assessment
of which nucleotides are critical coding regions for changes that
would result in greater infectivity of humans. This would allow
the a priori determination of what observed changes, in the genome
and/or haemagluttinin molecule of currently circulating H5N1 viruses,
should suggest emerging human adaption and should trigger a wider
pandemic response, notably the large scale production and administration
of an H5N1 influenza vaccine. I understand that certain British
research groups, notably that of Queen Mary College, London, are
involved in similar work to this. It would be worth seeking information
as to progress and inquiring whether, in practice, it could be
adapted in the sort of ways that are proposed.
How great are the risks, and what confidence can
be placed in these figures?
4. The careful documentation of the impact
of the three pandemics of the last century (1918-20, 1957-58,
1968-69), not to mention of the two years where previously encountered
strains reappeared after an absence of some years (1976, 1989)
allow intelligent estimates of the likely scale of the potential
What is the current assessment of the likely impact
of pandemic influenza on the UK (both in terms of health and on
wider society, including the economy)?
5. The central planning assumptions, based
on historical experience, anticipate a cumulative clinical attack
rate of 25 per cent as a culmination of one or two approximately
annual waves of pandemic activity, each of eight to 15 weeks'
duration. This is very reasonable.
6. More speculative would appear to be some
of the prognostications of wider societal breakdown. Previous
pandemics in the 20th century did not result in this and it is
difficult to advance the argument that society today is somehow
more fragile than it was in those years. Nevertheless an influenza
pandemic would be disruptive, although the historic experience
suggests that this disruption is, with difficulty, manageable.
Are the measures described in the revised UK Influenza
Pandemic Contingency Plan adequate to minimise the effects of
a pandemic? What more could be done?
7. Work to introduce the necessary operational
detail into the UK Influenza Pandemic Contingency Plan appears
to be getting under way. It is necessary to recognise the critical
role of the National Health Service, particularly Primary Care.
The latter, which will have a key role in distributing antiviral
treatments (below), is the key resource and engagement with general
practitioners, community pharmacists and their representatives
is vital and needs to be commenced urgently.
How well prepared and co-ordinated are health,
emergency and other essential services for responding to a pandemic?
8. The development of emergency planning
arrangements and local resilience fora, based on police force
areas has been a helpful development, in a wider sense, for providing
a focus for collaboration across the public sector more widely.
However these arrangements were primarily designed to address
major incidents unfolding over a few days or hours. They are less
adaptable to the circumstance of pandemic flu where the problem
lasts for several weeks and the key resources are in the health
and related care sectors.
9. The health sector continues to digest
various reorganisations and changes in contractual arrangements
that are primarily aimed at reforming the delivery of personal
health services rather than at public health. These affect the
collaboration and co-ordination of infectious disease services,
a problem that the Committee acknowledged in Fighting Infection.
Thus, for example, organising the delivery of antiviral treatments
and if appropriate, vaccinations, may prove to be more complicated
in Wales than it might have been previously. This is, in part,
a result of the abolition of the five health authorities and their
replacement by 22 local health boards and of changes to the out
of hours GP services brought about by the new GP contract.
What is being done to ensure that the general
public are aware of the risks and likely effects of a pandemic,
and of how they should react?
10. Welsh Assembly Government is, we understand,
participating in the wider public communications package being
organised by the Department of Health.
Is the UK's stockpile of antiviral treatments
adequate, and how will it be distributed? What steps are being
taken to ensure that the UK has access to sufficient antiviral
treatment and vaccine in the event of a flu pandemic?
11. Once the UK's stockpile of 14.6 million
doses is in place in April 2007, it should be adequate to treat
the number of clinical cases that are likely to arise. Details
of their distribution need to be worked out urgently and any potential
contractual or legal obstacles ironed out.
What will be the role of vaccine development,
manufacture and distribution in responding to a pandemic?
12. Traditionally, vaccines have only been
available subsequent to the initial pandemic waves of a new influenza
strain. They would then be incorporated into seasonal vaccination
13. A decision has to be made as to whether
there is sufficient justification for vaccinating certain groups
with the H5N1 vaccines being developed, at present. If not at
present, then criteria for initiating such vaccination would be
helpful. They could conceivably be based on molecular biological
and information technology techniques (para 3 above).
23 September 2005