Examination of Witnesses (Questions 248
- 259)
MONDAY 15 OCTOBER 2007
PROFESSOR DOUGLAS
YOUNG AND
PROFESSOR GLYN
HEWINSON
Q248 Mr Drew: Welcome everyone. We
will make a quick start. Can I say from the outset there may be
a vote so we will have to disappear. The idea is to try and do
a fairly succinct investigation into the progress with vaccine
work in bovine TB. We will aim to finish somewhere about 5.45pm
because Members have other things to attend to. We are a quorum.
I am standing in for Michael Jack and I am very pleased to do
so. We have before us Professor Douglas Young and Professor Glyn
Hewinson, both of whom are working in this area. I think it would
be helpful, gentlemen, if you work on this word succinctly and
just say very quickly what work you are undertaking in terms of
your own institution to give us a feel for where we are coming
at it from. Perhaps, Professor Young, could you make a quick start.
Professor Young: I am a professor
of medical microbiology at Imperial College. I also work at the
National Institute of Medical Research at Mill Hill. My main research
interests are in tuberculosis in general so most of my actual
research is on human tuberculosis. My involvement on bovine TB
is that I chair VPAG, which is a Vaccine Programme Advisory Group.
I am also the project leader on a bovine TB project out in Ethiopia.
Mainly I come from the human TB side.
Q249 Mr Drew: Professor Hewinson?
Professor Hewinson: I am the leader
of the TB Research Group at the Veterinary Laboratory Agency and
also a visiting professor at Imperial College, London. My group
is engaged in a number of areas of research activity to do with
bovine tuberculosis. The areas that are of interest to this Committee
are the development of vaccines for cattle and for badgers and
diagnostic tests which can be used in conjunction with those vaccines
in cattle.
Q250 Mr Drew: Thank you both very
much. If I could declare a quick note of interest. I have been
to the badger vaccine trial site, which is in my constituency.
We will come on to look at the badgers. I want to start with the
possible search for a vaccine with cattle. I return to the evidence
you gave to us, Professor Young, three years ago where you were
arguing in terms of a vaccination strategy and we were very much
working at the edge of science. Is that still the case? We are
quoted religiously this idea that we are ten years away from a
vaccine, that is a mantra that is repeated. How do we get the
ten years down to a much more acceptable and hopeful figure because
farmers are looking for this? I think the one thing this Select
Committee, both in its current guise but previously as the Agriculture
Select Committee, has always argued is there needs to be a plan
B. We have never said what that plan B is but I suspect that most
of us would work on the proposition that is at least using the
vaccination strategy as a central point to that. How do we get
the figure down from ten years?
Professor Young: We have worked
very hard over the last few years to get away from always ten
years into the future by trying to sketch out a plan where there
are certain bits of research activity that have to go on and these
take a certain amount of time but that we can map our way through
that. I have tried to do that in this briefing document to try
and give you some idea of where we are in those activities. It
is true for both the human vaccines as well as the cattle vaccines
and there has been a lot of progress in the last few years in
the human vaccine really defining endpoints of that and really
defining realistic times when we can get through to having a vaccine.
I think we have sketched out a scenario for the bovine TB in the
same way that we can see an endpoint. It does take ten years so
there is a certain biology of this disease, it does take a certain
amount of time just to go through the number of experiments that
you have to go through. You cannot necessarily magic away the
ten years but you can say, "Well, we are now three years
further ahead than we were last time I spoke to you".
Q251 Mr Drew: So is that seven years
now?
Professor Young: I cannot remember
exactly. When did we come?
Q252 Mr Drew: Even I can work out
ten minus three equals seven.
Professor Young: I think I said
15 last time. I think we do come out with these time points when
it is realistic from the research point of view when we can complete
those experiments. There is scientific uncertainty underlying
those but these are experiments so they either work or they do
not work. If they work in our favour then we have time points
when we would have vaccinations.
Q253 Mr Drew: Can I interject there
to put this into some context. The period of time, is that because
in a sense the efficacy of what you are carrying out has to be
given that period of time? You may have a successful vaccine,
you may feel that this is the way forward, but until you have
absolutely nailed it down in terms of all the possible outcomes,
some which may be good, some which may be adverse, you would not
dream of putting this out on the marketplace.
Professor Young: The way that
we can tell whether we have a successful vaccine is whether an
animal gets protected from the disease and the disease takes a
length of time to develop so we have to vaccinate animals, put
them in a situation where they may or may not develop disease
and then monitor whether they get disease or not. The turnaround
for that is about 18 months just for that simple experiment.
Q254 Mr Drew: In terms of what we
already know, because we will come on to the BCG as being the
preferred route, although of course there are other vaccines that
we would like to hear about also being tested, to what extent
is it possible to derive real scientific understanding from our
work with human beings in this area in as much that in the developed
world it is wrong to say we have cracked TB but we have largely
reduced it to a level where it is no longer seen to be a developed
country problem. What about the issue of learning from the human
analogy, is that feasible or difficult?
Professor Young: One lesson that
we can learn is that globally we think that BCG in humans is most
effective if we give it at a very early age. We think the activity
of BCG in humans does not work so well when you go back to your
environment so we use it as a neonatal vaccine. As part of the
research programme on bovine TB over the last three years it has
been shown that it works better as a neonatal vaccine in cattle
as well. That would be one simple bit we have learnt. The other
analogy is while we are trying to make a better human vaccine
what we have settled on is that we need to stick to BCG and add
something on top of that. That is the way the human vaccine development
is going on and that looks like the best way forward for the cattle
vaccine.
Q255 Mr Drew: Can I be clear that
there is an infusion, if you like, from the understanding of the
human being as a test case for possibly working on either cattle
or badgers in the area of bovine TB?
Professor Young: There is good
overlap between the two. I think we do learn from them.
Q256 Mr Drew: Professor Hewinson?
Professor Hewinson: I would pick
up on that in terms of many of the vaccines that are looking promising
for humans which are going into clinical trials—Phase 1,
Phase 2 and Phase 3 clinical trials—have or are being tested
in cattle as well, so the most promising vaccines which are coming
out of the human field are being tested in cattle. We should have
a fairly good idea if those vaccines are looking promising for
cattle within the next year. Of course you have to wait another
ten years for Phase 3 trials in humans so you will get a better
idea.
Mr Drew: I think we will come on to time
a bit later.
Q257 Mr Gray: I am a bit thick perhaps,
I did not quite follow what Professor Young was saying. At the
beginning of our session, could you clarify, do you believe that
it is or is not going to be possible to produce a vaccine for
cattle and, if so, roughly speaking, how long will it be before
that arrives? The last time you gave evidence to us, two or three
years ago, you were extremely cynical about it and you were really
saying it was probably very unlikely. Do I detect that you are
slightly more optimistic now? Is there or is there not going to
be a vaccine for cattle?
Professor Young: I cannot give
you a yes or no answer. I would say on balance I would be optimistic
and the date that we give here is for an improved cattle vaccine
by 2015 which would be eight years. It is not a matter of just
saying, "You take these steps and it will happen", there
is a scientific uncertainty.
Q258 Mr Gray: Of course. In terms
of saying to the world and to the farmers what they should expect,
you are saying as the experts in the field you would hope that
(a) it is possible to have a vaccine and (b) we would hope to
have that by 2015. That is my understanding, is that correct?
Professor Young: Yes. That is
what I would like to try and bring forward, to try and get those
hard dates.
Professor Hewinson: I would say
that there have been advances over the last three years that give
us more hope in terms of developing a vaccine suitable for cattle.
Q259 Mr Drew: What sort of advances,
Professor Hewinson?
Professor Hewinson: I think the
two things which have happened in the last three years are firstly
the development of diagnostic tests which differentiate between
vaccinated and infected animals.
| 
