Select Committee on Environment, Food and Rural Affairs Minutes of Evidence

Examination of Witness (Questions 240 - 259)



David Taylor

  240. Professor Anderson, it will be a surprise to many, your comment that contiguous culling saved animal lives, which seems, to me, unproven and possibly even a little provocative. Did you hear the Chairman refer, earlier on, in the session with Professor King, to yesterday's Hansard, 146W, which showed over 7,500 mainly Dangerous Contacts, and a few Slaughter on Suspicion cases were referred to, had laboratory tests of which just five yielded positive results? Were you able to input into your model, as the outbreak continued, the fact that so many of these, virtually all, contiguous cases, in fact, had no clinical sign of the disease at that stage; and would you expect, with this admitted hindsight, that there will be further refined models which might indeed move away from mass contiguous culling as the best reaction?
  (Professor Anderson) Yes; two important questions. Can I deal with the second one last, because it is a much more difficult one to deal with. You heard Professor King and Dr Grenfell and Professor Woolhouse comment about the 17 per cent and 50 per cent figures; and, to me, that says it all. It says that most of the transmission is local, by whatever route, and the route is uncertain. If you have not acted on that local transmission you then get spread to a further contiguous ring. And then most of Britain, with the high-density livestock regions at the front, would have been susceptible to the spread of this virus. And, as I think I said, very publicly, on a `Newsnight' programme, in the early stages of this epidemic, given the density of livestock holdings in the UK, a complete disaster was possible at that time, and it required speedy and draconian action to prevent that happening. Now, moving to the future, the future is more complicated. The medical vaccine development areas tend to be a little bit more advanced than some of the veterinary fields, because commercially there is more money in it for the pharmaceutical companies, or vaccine-producing companies; the production of veterinary vaccines is a bit of a non-profitable area. And, one of the real difficulties with foot and mouth, all of us would like to see, where there is a good vaccine, every animal, at birth, immunised. Then, given that the vaccine has a reasonable duration of efficacy, you would like to see that repeated with each new birth cohort each year, and then the consumer would bear the cost, the cost of that vaccine, and that is the rational and logical way to go. But the questions here, and my own department did a review of the vaccine data for the foot and mouth, because there was a lot of confusion at the early stages about, how long would the vaccine provide protection, what efficacy would it give in different species, did it work properly with this strain of virus, and the harsh answer is, (a) it takes X days to create the protection, so you have got a further time delay of three to five days, minimum, in some cases you might have a delay of seven days, before immunising that contiguous ring actually gives you protection. Then the question, how many doses of vaccine have you got available; if you dealt with Cumbria alone, you are talking about tens of millions of doses, almost, to create herd immunity—it was not available. The vaccine is stored as a concentrated antigen which then needs a lengthy process of preparation into dilutions and vaccine doses, and that was not available; there was an emergency vaccine available within the European Union, but I think about 1.5 million doses, but do not take that as gospel, the number needs to be checked. So in the early stages it was not a practical option. But in the future, clearly, a great deal of scientific attention should be paid to this problem, and also one needs to think of production, which commercial company might be induced to produce such a vaccine, given that on any vaccine there is a very low profit margin; but the European Union has got to address that question broadly.

Mr Martlew

  241. I am a little worried, the way the debate has gone today, because we have been mixing foot and mouth with BSE, and can I congratulate you on answering a very good question that nobody asked, about the numbers of possible BSE cattle in the future. But the reality is, of course, they are very different, our concern over BSE is because it can be transmitted to humans; there is no concern whatsoever, is there, Professor, that foot and mouth can be transferred to humans, so it is totally separate?
  (Professor Anderson) Yes; correct.

  242. And, therefore, it is an animal welfare disease, so in many cases people would say we were tackling an economic disease for the agricultural industry. So what you are saying is that the contiguous cull saved lives; that was only if we carried on a policy of becoming foot and mouth free, in actual fact, was it not?
  (Professor Anderson) Yes.

  243. And that is a policy that really has not been examined. Did you look at the options of not carrying out a cull, losing our export trade and treating the animal welfare problems that it would have created?
  (Professor Anderson) It is an important question, but we did not, for a very good reason, it is not within our expertise. The role of the different scientific groups was to provide as good a scienctific analysis as was possible on the timescale, putting the economics, the cost/benefit, in. If you had done a cost/benefit analysis of vaccine versus contiguous cull prior to this year, and you had the interval 1967 to 2001, my guess is, although I do not know the precise answer, that the cost/benefit analysis might have fallen against vaccination, in other words, deal with very infrequent disasters, costly as they are, they are infrequent. I think the game and the environment have changed significantly now, post this epidemic, and therefore it needs good agricultural economists, or good economists, to come in to look at the cost of various options, in light of our experiences during this epidemic.

  244. So we are actually responding to the way we dealt with it before, are we not, that we must get rid of this disease from the UK?
  (Professor Anderson) Europe.

  245. And the way to do that, we are all focused totally on which was the best way to do that, and you think the approach that we have taken was the best way, but nobody actually looked at the wider picture of `what if we decide not to do this, it is an animal welfare problem, with regard to sheep it has very little effect on sheep, we will lose our exports, but that is an option'; but you are telling me that you did not look at that option, and, as far as you are aware, nobody else looked at that option?
  (Professor Anderson) It is a question in the review of what happened, and I think it is very important to bring the economic aspect in. I think it is also important that this has got to be decided within Europe, this is not a UK problem, in fact, it is a western, developed-world problem, and it is a problem to do with where the import/export of livestock occur. And it would be sensible, in light of our experiences, to look very broadly at these issues, absolutely right.


  246. Professor Anderson, we have talked a lot about vaccination strategies, and, of course, there are various strategies, it is not simply a vaccination option, there are a number of them. In your modelling, are you able to build in the intervention of particular forms of vaccination, at certain stages of the disease, and to come up with an idea of the efficacy of it?
  (Professor Anderson) Yes, we are, and in the first paper—we considered vaccination, by the way, from day one, post the consideration of the time delays of the index premise removal, for the simple reason that the group has a lot of experience in designing mass vaccination programmes for humans, the problems are somewhat similar in terms of concept. And in the paper published in Science, in April, there is a consideration of a variety of approaches to immunisation and comparative analyses of their effect versus culling. Dr Grenfell, more recently—it is easier to do these things with hindsight, it is more difficult to do them on a very fast timescale, we had two weeks to do this—is doing a more detailed analysis of a subtle variation of looking region by region and mini outbreak by mini outbreak, how effective immunisation would be versus culling; and the unpublished results of that, to date, as Dr Grenfell mentioned, are, broadly speaking, because of the properties of the current vaccine, and he has taken optimistic assumptions about those properties, that, still, there are many question-marks surrounding the effectiveness of it. That is unfortunate, and what is required, as I think Professor King said, is a careful look at how we can use the modern technologies of vaccine development for many different strains of the virus, in medical terms these are called multi-valent vaccines, and just recently there have been enormous scientific strides in producing multi-valent vaccines for pneumococcal and other diseases; that technology needs to be applied in the veterinary area, we need to have a better vaccine.

  247. So a significant part of the debate then about vaccination, and particularly the people who claim that vaccination would have offered the complete answer, as it were, in terms of the scientific, perhaps availability, but certainly its readiness, then, quite frankly, that is an argument which is relevant? There never was a plan B, is what I am trying to say, was there?
  (Professor Anderson) There was a plan B. Vaccination was considered, as shown in the minutes of the OST Science Group meeting, virtually at every meeting; scientific questions were raised, answers were sought, it was on the table from day one, and it was predicted to be less effective.

  248. If you had been present, you may well have been present, if the Prime Ministers says, "Well, Professor Anderson, I'm under terrible pressure here to vaccinate, I've got St James's Palace at one end and farmers down in Devon at the other end," that was quite a good shot in the dark, that, I think, "But I have to tell you that, if you think you are going to find a much easier way out by vaccination, it just is not true," that would have been the nature of the advice you would have given on this?
  (Professor Anderson) The scientific advice was exactly that. It is based on three factors; it is important to get these correct. One, the properties of the individual vaccine; two, the logistics, do you have the manufacturing capability, do you have the vaccine available; and, three, a very important epidemiological consideration, which is, if, instead of culling the ring, I immunised the ring, as Professor King mentioned, already you have got 17 per cent transmission there, if you deliver the vaccine to an already infected animal, the experimental evidence suggests that it does not prevent fulminating infection in that animal, and therefore the virus spreads to the subsequent ring. So it was a very reluctant decision, because I think everybody would have liked to have used different routes, if there had been an effective other route.

Diana Organ

  249. You have laid before us the option which was used, the cull and the contiguous cull, the option of maybe not using vaccination, or whatever; what about the other option, because you said, on Newsnight, "We wanted to avert a complete disaster"? I would suggest to you that in those rural areas that were hit by foot and mouth it was a complete disaster, and particularly to their tourist industry, if nothing else. What about if we had done nothing, because we are not talking about, as Eric was saying, human health here, we are talking about animal health, what about if we had done nothing?
  (Professor Anderson) I refer you to page 545 of the Nature paper in October, which gives some risk maps, based on livestock densities for the UK, a very detailed analysis of that; there are scales of disaster, this is a higher order scale of disaster than what actually did happen. And I could not agree with you more, totally devastating. I live in an agricultural community in Gloucestershire; totally devastating, but it could have been far, far, far worse.

  250. On the basis that you are saying it could have been far, far worse, because the question has to be that we have always started from the premise that this disease came from the beginning of Heddon-on-the-Wall going to Essex; but there are some people around that say, "Oh, no, no, no; we've had little bits of this knocking around for a long time, and that in sheep it's very difficult to tell the difference between orf and foot and mouth," how do we know, from the beginning of your modelling, that you are not looking at the beginning of an upright curve, that actually is the sort of tail end of something that has been going on a lot longer?
  (Professor Anderson) I have had a lot of comments like that from farmers, anecdotal evidence, that, of course, it was around, even the suggestion that Christl Donnelly published her paper in year 2000 about foot and mouth and speedy action because she already knew it was there: complete rubbish, in my view, to be honest. Foot and mouth, if present, even in sheep where it is clinically difficult to diagnose, given our stocking densities and movement patterns, it would have exploded, as it did, in cattle, and even perhaps in pigs, and it would have been very transparent. Now determining the precise point of entry prior to 20 February, of course, the starting-point of any epidemic is always very difficult, whether it is HIV, FMD or BSE, and you are never going to know with precision, it probably was at least ten to 20 days prior to 20 February, but I cannot be more certain than that.

  251. Thank you for dispelling the urban myth that it has been around for at least a year before.
  (Professor Anderson) I think the screening and testing side of this is important, in medical epidemiology you use serological testing; today there are extraordinarily precise methods. If I had a bit of saliva from you all in this room, I could tell your entire infectious disease history!

  252. Do you want us to spit in the cups? From here, that is a little tricky.
  (Professor Anderson) On a bit of blotting-paper. And I think these technologies, hopefully, will come in very strongly into the veterinary fields; and everything lies in quick, accurate diagnosis. And, in our current fears about other problems, that is equally important.

Mr Martlew

  253. Just a point, going back to vaccination, obviously, the earlier witnesses gave the same information about vaccination, but, in reality, in Cumbria, it was recommended by the scientists; now the scientists now say, "Well, it wouldn't have worked anyhow." But the reality is, it was recommended by the scientists and it was turned down by the politicians. So how can you say that the scientific advice was not to vaccinate when in Cumbria it was, of course?
  (Professor Anderson) The scientific question came, and it was from DEFRA, and it was a very important concern that was raised, here we have the husbandry problem that in April to May cattle are turned out on fresh pastures to boost milk yield, etc., etc.; is this a real danger for foot and mouth, number one, and number two what options are available to minimise that risk. One was, keep them in the cattle sheds for a longer period, which was adopted; two was immunise the turnout cattle, because they are very valuable. So we were asked to look at immunisation of the cattle and to address two questions, would it minimise risk of spread, one; two, how many animal lives would it save. And we provided a set of scientific scenarios, as best as we could at that time, concerning those issues. There was never a clear scientific recommendation, it is not my place to do that, it is OST's to do that to COBRA, David King's; we just looked at the scientific options.

  254. But the recommendation was to vaccinate?
  (Professor Anderson) The recommendation was that it could save animal lives, but not many, and that there was an associated risk with it.

  255. But, sorry, that was what Professor King said?
  (Professor Anderson) Professor King said, he posed the question how many animal lives would you save, to us, and it would have saved animal lives, but there were considerable risks attached to it, which he did mention, about jumping outside, because the vaccine was not very efficacious.

  256. But the recommendation from the scientists and the Government was to vaccinate?
  (Professor Anderson) It is best that you put that to OST. My role is to do the scientific work.


  257. When you were discussing this, when we talk about vaccination, the first argument, broadly, against it was that our whole disease-free status would be at risk; then the argument was that farmers would not have it. The next time it came round the argument was that the consumers would not have it. As a scientist, did you wonder whether politicians were finding bad reasons for things they believed by instinct, or how do you analyse a political response to your recommendations?
  (Professor Anderson) The scientific advice that went, which is in the minutes of the meetings, was that immunisation, even with all its imperfections, given the properties of the vaccine, could save, in cattle turnout situations, some animal lives, but only if the compliance, in other words, the uptake of the vaccine, by the farms that needed to be vaccinated, was moderate to high. Then the question comes, which is best directed to the National Farmers' Union and the other landowning associations, would the uptake of vaccine have been high; that is a policy question to which I am not aware of the answer, but my impression was that the Government followed, and this is only an impression, very carefully the scientific advice. So it was not for political spin purposes, it was on the basis of how best to quickly deal with this FMD spread problem.

  258. Can I conclude by looking at another, a related issue, but one which sometimes gets a bit overlooked; two issues, in fact. We are now, of course, doing all the serological testing in order to declare disease-free, or virus-free, as Mr Scudamore would say, and what we are discovering is that, here and there, there is some old disease. Now at the beginning we were all told that if animals got foot and mouth disease it was an absolutely ghastly thing and you could not possibly let them live through it because it was all too nasty. It looks like sheep can get this and sort of shake it off, does it not? If you find old disease in sheep in the Pennines now, for example, does it matter?
  (Professor Anderson) I think it does matter, it matters obviously in terms of the foot and mouth fear, it is under the current legislation or rules for the European Union. But we only sub-sample the population. Say you have got N thousand sheep spread over a large area, you take some sub-sample of them, typically designed to detect a 1 per cent prevalence; the fact that you get some positives, which are old infection, does not necessarily mean that you do not also have some active infections, because it could be slowly spreading through that particular region.

  259. So, at the moment, when they do find some old infection, they cull, so that is the correct thing to do?
  (Professor Anderson) In my view, yes.

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