Examination of Witnesses (Questions 300
- 319)
MONDAY 15 OCTOBER 2007
PROFESSOR DOUGLAS
YOUNG AND
PROFESSOR GLYN
HEWINSON
Q300 David Taylor: The crucial question
is has any nation at any time and in any place ever demonstrated
evidence that TB in cattle can be controlled by vaccination?
Professor Hewinson: There have
been a number of studies, in fact using BCG in cattle, over the
years. The story was very much the same as the human story: in
some trials it worked very well and in some trials it did not
work at all. It is not clear, because the methodology used is
so different, why it sometimes succeeds and why sometimes it does
not succeed. The most promising trials that were done were actually
done in the United Kingdom. There is some evidence that BCG vaccination
reduced infection by about 50% in cattle. The reason BCG was never
used for control was that it sensitises cattle to the tuberculin
skin test and, therefore, you could not carry out a test and slaughter
strategy along with BCG vaccination. That was the major overriding
thrust of why BCG was not used in the 1950s.
Q301 David Taylor: Are you both convinced
that progress is being made? The Chairman, at the start of his
remarks, talked about a ten-year time frame. It still seems to
be a bit like a mirage: we complete three years work and we still
seem to be a decade away from something specific, hopeful, tangible
and effective.
Professor Hewinson: I would hope
that the timetable we showed you and the discussion we have just
had means than an injectable BCG vaccine could be licensed by
2010, then how you apply that and use it needs to be looked at.
A licensed product could be available within three years.
Q302 Mr Drew: That is for badgers.
Professor Hewinson: That is for
badgers. I should also say that the legislature requirements have
gone up almost exponentially in the last ten years, so instead
of a dossier so big you need a table full of dossiers to achieve
the same thing, some of which is scientific and technical—we
are working at that edge of knowledge—but some of it is
also legislative and bureaucratic. We are spending millions of
pounds showing that BCG is safe in badgers and it is being used
in more people than any other vaccine.
Q303 David Taylor: Do you agree with
that robust confidence?
Professor Young: Yes. On the research
side I think we can produce these things and we have given dates
when we can produce them. Whether the impact of them will be sufficient
to fulfil the policy needs still needs consideration.
Q304 Mrs Moon: That 2010 date you
gave us, does that become 2011 if you do not do your work this
summer? Will it not move it on?
Professor Young: No. What will
happen is we need a certain amount of time to elapse anyway so
we would have been looking at the vaccine trial badgers now and
we would be looking at them again next year. We will just miss
a little window in between. I do not think we will lose a year
on that.
Q305 Mr Drew: In the sense that the
international comparisons are very interesting, because we are
all looking at similar but not necessarily the same studies, are
any of those studies internationally looking at the impact of
a vaccination strategy on cattle alongside a vaccination strategy
on a particular wildlife reservoir? This has always been one of
the issues: do you go for the cattle vaccine, do you go for the
wildlife vaccine or do you go for both on the basis that the herd
immunity could affect, one hopes optimistically, not just the
herd you are vaccinating but the other species, which is part
of this problem. Is there a relationship between wildlife and
cattle or is it always cattle or wildlife?
Professor Young: New Zealand is
all wildlife now; Ireland are still interested in cattle; in Africa
it would be all cattle. We are the only broad-minded community
that is doing both.
Q306 Mr Drew: In the great days of
international co-operation, that is a bit of a dilemma, is it
not? What is not to say that whatever effectiveness a vaccine
has in one species it would be much more effective if you were
able to vaccinate across species. This goes back to the issue
of the deer. Here we are solving a problem with the badger population
by vaccinating them but lo and behold the cattle impact does not
go down nearly as much as we had hoped because there is another
wildlife reservoir out there. Why is this not being looked at
in a more comprehensive way?
Professor Young: It goes back
to the business of sensitising the animals. The vaccination was
going to sensitise the cattle in a way that compromised the diagnostic
test used in the test and slaughter so it is illegal in European
law at the present time to use a vaccine in cattle because it
compromises the diagnostics. You had to have that advance.
Q307 Mr Drew: Let us be optimistic
and we do get that differentiation between those that have been
vaccinated as against those who have the disease. We persuade
the EU that we know what we are doing because we have now separated
those animals out and have an effective vaccine, but again it
would be helpful if we all had, at the same time, a wildlife vaccine.
It is an interesting thing because we are not doing it together.
The badger vaccine experiment is purely on the badger and the
impact may be measurable in terms of the cattle, but the cattle,
of course, I cannot judge because I have not seen the cattle vaccination
work. I do not know if that is having an impact on the badger.
Is this not something which is a bit of a hole in the scientific
hypothesis?
Professor Young: I would concede
that, yes; I think you are right. In order to control this disease
you do have to work on both of those populations.
Q308 Mr Drew: It would be pretty
sensible to have some element of working on them together.
Professor Young: Standing back,
scientifically I agree with you, but in practical terms that is
the way it worked out. It is difficult to combine the two programmes.
We keep them co-ordinated if we are talking about both but it
would be the morning badgers and the afternoon cattle. It is very
difficult to put together a practical programme where you are
running them both together at the present time. The next stage
of looking at the badger vaccine will be to have a cattle read
out. That is where we would like to go but it does have an increase
in the magnitude of the trial you are looking at.
Q309 Mr Gray: Defra are spending
currently £10.5 million on research all together. How is
that divided up between the two?
Professor Hewinson: I think it
probably splits into about £3.5 million a year on cattle
vaccine and £2.5 million on badger vaccine.
Q310 Mr Gray: Is that the right split?
Professor Hewinson: Because with
badgers our only option is BCG, there is not that development
work required to produce vaccines that are better than BCG. The
cattle work is more scientifically demanding and requires more
of that.
Q311 Mr Gray: £3.5 million and
£2.5 million makes a total of £6 million. I thought
Defra were spending £10.5 million so what happened to the
rest of it?
Professor Hewinson: I do not know.
Mr Gray: The learned clerk has given
me a piece of paper telling me Defra is currently spending £10.5
million.
Mr Drew: That is over time. I do not
know if you want to give us a note on this. There is some question
about what money has gone in and how it has gone in.
Q312 Mr Gray: It would be helpful
to have a breakdown as to who is spending what.
Professor Young: The ball park
numbers I have are: £5.5 million per year at the present
time on vaccine and £18 million from 1998 to March 2008.
That is the sort of numbers.
Q313 Mr Gray: What about CEDFAS,
is that going to be beneficial to this research, Combating Endemic
Diseases of Farmed Animals for Sustainability?
Professor Hewinson: There were
two projects that have been funded by the BBSRC in that area:
one is dealing with one of the questions raised, is there any
evidence of genetic resistance in cattle, and the other project
that I know was funded was looking at strain differences, so the
different strains of M. bovis that are in the country and is there
any evidence that these strains are evolving to escape a skin
test. It does not directly feed into this work. The other point
I should make is the really expensive aspect of this work is in
the containment facilities that are required for the cattle work
and the badger work and indeed the field work. A lot of the money
is going on animals rather than scientific endeavour.
Q314 Mr Gray: Are we spending enough
on it altogether overall? Is it the sort of thing where if you
pile in tons of money we will actually find a solution or not
really?
Professor Young: One of the ways
that if we use more money we would reduce the risk, as I said
right at the start, is the biological determinism in this time
frame, how quickly we can get it out. I do not think necessarily
money can shorten that dramatically. Where money could be put
in would be if we would do more things in parallel and that could
certainly be done. We have a fairly slender track where we are
doing just one thing at a time. If that works, that is fine. If
we had more money we would reduce the risk by trying more options
simultaneously.
Q315 Mr Gray: I saw the secretary
note that down so you will not be getting more money now!
Professor Hewinson: There are
two bottlenecks and the first is in testing the vaccines. You
have investigated this a bit, both in the field and experimentally.
There are not that many facilities which allow that testing so
that really is a bottleneck. The second thing is in the fundamental
research and understanding of what constitutes protection. I think
that area could also benefit from more funding.
Q316 Mr Gray: To wrap-up our afternoon
discussions, I mentioned in passing we had the Minister sitting
in the audience, and no doubt officials with him. What else should
be the government be doing in this whole area looking into vaccinating
cattle?
Professor Hewinson: In terms of
trying to move things faster?
Q317 Mr Gray: In general what would
you like the government to be doing that they are not currently
doing?
Professor Young: The area I would
highlight, which they are beginning to do, is that for the many
years we have sat here it has been down to the researchers to
come up with this vaccine which is going to magically make everything
disappear; there will be some magic bullet which will come out
from a laboratory and all the problems will be solved. I do not
think that is realistic. We can produce a range of tools, injectable
BCG or different vaccines for potentially different efficacy,
and I think the government has to think very carefully how you
would use these as policy options. What do you think a vaccine
would do? How would you use it if it had 80% protection? Would
you use a vaccine that would have to prevent all the animals ever
getting any disease whatsoever or would it be sufficient for a
vaccine which controlled outbreaks or controlled transmission
of the disease? I think to get a little more policy formulation
from the top as to how we would use the vaccine would be enormously
helpful from the development point of view because then we would
have clearer end points as to whether our vaccine is working or
not working. That is something which has only happened in the
last year or so where Defra have begun to take that on board and
it is a very positive move.
Q318 Mr Drew: I take that point up.
In the paper, which presumably came to us from Defra or you wrote
it on behalf of Defra, basically that sentence you said at the
end of how good is good enough: "The availability of vaccines
does not necessarily equate to use. The balance of costs and benefits
will remain a question of policy makers", when Edward Jenner
came up with the vaccine for smallpox, nobody knew whether it
was actually going to eradicate smallpox. The policymakers thought
we have no alternative here. We have people dying by the thousand,
let us stick it in them. Cattle pox is what we gave them and lo
and behold we cured smallpox in all but name. Why do we not get
on with it? Why do we not say this is our next best alternative
to watching us spending millions of pounds slaughtering lots of
animals which is getting us no further forward. Let us get on
with it. Let us do a big-scale experiment. Let us tell the New
Zealanders and the Irish and the Americans what we are doing and
hope they get behind us and maybe do similar things. It has got
to be better than what we are doing at the moment.
Professor Young: It did take us
200 years to follow up on Jenner.
Q319 Mr Drew: We have gone somewhere
in the last 200 years.
Professor Young: I do not think
you just jump in the deep end immediately. What we would like
to do is get a little bit of evidence that we are moving in the
right direction and the badger vaccine experiment is moving us
towards that. I would like to see a little more evidence before
I would jump into your big experiment.
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