One saw the... the phases when things were still major epidemics. In the one case, measles because there wasn't a vaccine, and in the other case pertussis. There was a vaccine, but it wasn't quite widespread enough, and one thing is they were both very bad diseases even in a relatively wealthy country, and in the Third World they're major killers of children. And the vaccine controversies that happened, they were long apart. The pertussis one happened in '79 and '80 because there was a report of children being brain damaged by pertussis vaccine, and it was never really authenticated. It's very hard to disprove a thing like that really, but it did lead to a huge lack of confidence and a huge diminution in the, in the amount of triple vaccine being given, far greater reduction than the recent one about MMR. And the result of that was, two, well actually I think three, but two very substantial epidemics of pertussis, and it illustrated an interesting scientific point and also a public point. The scientific point was that you need to immunise a large proportion of the susceptible population, and keep that level of immunity up before you really control the disease and the... the sort of public policy side is that a good vaccine is really its own worst enemy because as the vaccine works more and more any, either known or putative adverse effects, get thrown into sharp relief. I mean the really gross example is polio, which is of course a dreadful disease, and as its vanished the odd person, one in a million, gets polio from the vaccine, but one in a million's too many if there's no polio.

[Q] Yes, yes.

Actually it's quite interesting. I was reviewing a recent book on smallpox and, you know, variolation happened before Jenner giving, you hope, attenuated smallpox to prevent further attacks, and that whole issue came up about the cost benefit, as we would put it now. And the... chap who was the secretary of the Royal Society did research on this and showed that despite the harm from vaccine it was still a jolly good thing to do. That was when smallpox probably killed about 7% of the population, because as it became controlled was vaccine harmful became a much more cogent question and that's still... that issue is still very much with us today because, in fact, this chap Jurin said some quote to the effect that people see potential harm much more when they don't feel a... in danger themselves, which is perfectly true.

[Q] Yes, yes, yes, yes.

So it was, it was an interesting phase that. But pertussis is really a very nasty disease. I think the Japanese, which I don't know, but I think the name means 100 days cough and the children could be awfully ill and coughing in the most awful prolonged way and really very sick for weeks and weeks on end and driving their parents to distraction. As I say, in a rich country, except for the neonate, it's not really actually a life-endangering disease, or very rarely so, but it's still a singularly unpleasant disease and the cough... actually to see a small baby taking a breath and going completely blue and not breathing, I've known very experienced ward sisters who felt really panicky, as I did, I mean they, well, mostly, thank goodness, they start breathing again, but it's, it's really a terrifying. I once gave a lecture at the Royal College of Physicians and I took a tape of, a child having a coughing and apnoeic spell with pertussis, and you could feel the audience's toes curling up because they felt... it's really terrifying, a really just frightening thing to see and to experience.

[Q] And, and does it sometimes happen that a child does die?

Well, yes, small. It's obviously more lethal for neonates and small babies and they can die. They go into intensive care now, of course, and in, in previous generations and in poor countries today there's a very substantial death rate, but it's mostly, parents are naturally terrified. The other thing, which now I think about it is that mostly between these attacks the child looks perfectly all right. So the, the mother brings the baby up to casualty or the child up to casualty and says she's having these terrible... and the doctor looks at the child, listens to its chest and... there's nothing wrong with it and what are you fussing about, but once you see the attack you know what she's fussing about. Extraordinary difference really.

[Q] And, and the death in pertussis is that usually, does that, the apnoeic attacks that you described, just so that people understand, is that, the breathing usually continues, doesn't it?

Yes. That comes good nearly always or nowadays with proper ventilation. It comes good with that, but it's pneumonia I think mainly in poor countries. I dug up the old autopsy books once for the Old Grove Fever Hospital and these really dreadfully painful lists of deaths with children from pertussis, bronchial pneumonia. And that chap Morley showed that, both in the case of measles and pertussis, the death rate and complication rate and complication types in, as he was there in Nigeria in these, I suppose in the '60s were just like they were in the 1900s and 1910s and 1920s in Britain. It was a, an ethnic thing or a genetic thing. We don't know, probably, probably nutritional and it was a devastating disease here and elsewhere but if, if you're not seeing it... you used to hear people saying what are they fussing about, measles.

[Q] Yes. Yes. And internationally is it still a, a threatening...

I don't know the recent figures. Measles and pertussis immunisation are much more widespread, but I imagine in the poorest places it probably still is. I don't know the answer to that.