 So, the title of the course is the Science of Everyday Thinking, and what we're doing here is looking at some of the claims that people make about immunization and vaccinations. And I just want to start off by doing a bit of myth-busting on a few of the common immunization myths. Is there any evidence whatsoever that heavy metals in vaccines cause any sort of difficulties? Is mercury a problem these days? Vaccines nowadays, at least in the developed world, do not have mercury in them anymore. It was taken out not because there was evidence that there was a problem, but because people were concerned that there might be without any evidence. The reality is that the small, very small amount of mercury that's present inside the vaccine material that's going in a routine vaccination is far less than you'd actually consume in the course of a normal diet. Right. And another common one is that newborns or small children are overloaded somehow. Their immune system can't handle all of these vaccinations. Well, the reality, of course, is that it handles all the infections that the vaccines are designed to prevent, and the vaccines are much less of a challenge to the immune system than the infections we're meeting, yet we still survive all the infections as well. So the reality is that the immune system is very adaptable. And it's also very selective. It only makes an immune response to what you give it to do at the time. So it's not as if you're wearing it out by musing up all the capacity because the capacity for everything else still exists even after you've dealt with whatever virus or vaccine you've just had. Some people think that vaccines have long-term side effects that we just can't see yet. And so they're being slightly risk averse to try to, yeah, they don't want to tempt fate or something for something that could happen in 30 years if it hasn't been tested appropriately. Is there anything to that? Well, that's the most difficult one to prove or disprove, of course, because the frequency with which people get rare diseases is low and everybody gets vaccinated or nearly everybody, and therefore you don't really have a comparison to say definitely these things are not due to vaccination. Having said that, the diseases that we recognize are no more common now than they were before routine vaccinations were introduced. Some of them become commoner because we're living longer now because we don't get the infections anymore, but there's no direct evidence that any particular disease has been attributable to vaccines. With one or two minor exceptions, I mean, some vaccines that were made in great haste to deal with infections such as the swine flu vaccine definitely caused rare autoimmune disease. It was only increased about twofold over what you would have expected to see, but it was definitely increased. That vaccine was never needed and isn't used anymore. But for the vast majority of vaccines, we've got so much data now to say that there's no evidence that these vaccines increase your risk of getting disease. And I assume then that the myth of vaccines or immunization causes autism is obviously incorrect. Well, that has been dismissed thoroughly now. And of course, the person who first raised that spectre has been shown to me present his data fraudulently to achieve an effect, and the total data set has given discredited. Wow. The last one, I think, is quite interesting. It's driven a little bit by what we've been talking about. The anti-establishment bias. And that would be that the pharmaceutical companies are driving the vaccine enterprise. And if they develop a vaccine, then everyone has to take it, and therefore profits roll their way. Well, the statement that you've made is true. A vaccine company exists to make vaccines, and because they are owned by shareholders, they are expected to turn profit. But the cost of developing these vaccines is extraordinarily high, and the risk is extraordinarily high too, because the vast majority of vaccines that are proposed never get out there to the market. So vaccine companies actually got to the stage where they're pretty well turning around, saying that we're not going to make vaccines anymore, we can't make any money off these. And it was only when the American government stepped in and said, look, we won't identify the vaccine companies against any potential claims for problems from the vaccine that the vaccine companies were really able to carry on making vaccines. Vaccine companies actually started as philanthropic organizations by and large, Commonwealth Serum Laboratories was a government organization that makes vaccines in Australia. The boroughs welcome was actually founded by Henry Welcombe as a philanthropic organization, and eventually became the welcome of trust, and the money that was made out of the vaccines is given back to research. Right. So are there any risks then with vaccines? Oh, sure. Every intervention that you do, there is a potential risk. Most vaccines are very, very safe. One in a million allergic reactions. That's about the same for almost all the vaccines that we currently give out. And that risk is obviously far less than the risk that can be associated with the infection that the vaccine is designed to prevent. Most people get a sore arm when they get a shot, and that's a risk that you take, but it's a pretty trivial outcome. And some people feel a bit flu-like, but in terms of long-term risks, they only clearly identified one is that you can get an allergic reaction when you get the vaccine, and some of these are severe, but about one in a million people that get a vaccine get an allergic reaction. Now, can you give us a bit of an indication of what this looks like? I mean, when a vaccine is being tested, we've talked a bit in the course about the experimental method, about placebos and experimental groups and the difference between them. How does it work with such a large sort of intervention like a vaccine before it goes out to market? What needs to be done? Well, the vaccines always go through a fairly similar sort of testing process. First of all, you demonstrate if there is an animal model that the vaccine will protect against the infection in an animal. If there isn't an animal model of the infection, then you at least test that the right sort of immune response is made in the animal to actually predict that it will protect a human. Then you do those ranging studies and a small number of healthy volunteers to see how much of the vaccine you need to give to give an immune response that you think will be protective. And then you go on to do studies which become increasingly more broad spread. Initially, they start focusing on the ideal target group and you basically compare the vaccine with a placebo and find out whether the vaccine protects. You, of course, have to wait until enough. People are naturally infected in the placebo group before you get an answer, which is why you need big trials. Then eventually you go out and take all comers and immunize and everybody that you would plan to immunize, including people who might have had the infection already, people who have recently been ill with other illnesses and basically try and give as broad a picture as possible of how protective the vaccine is vis-a-vis of placebo and whether there are any groups that are at particular vulnerable risk for complications. The most vaccines turn out to be safe in almost everybody that they're giving to the one exception is that if you've got an already-impaired immune system and one in 100,000 people are born with a significantly-impaired immune system, then you're not likely to want to get a live vaccine because the live vaccine might actually cause a disease you're trying to prevent if your immune system can't respond to the vaccine. And so how long does that generally take? Is that a long process? That's obviously an expensive process. Well, on average 20 years from the time when you start thinking about the vaccine to the point where it's actually out there as a product. But the trials, for example, for the papillomavirus vaccine took somewhere about five years before they could reach a conclusion that the vaccine worked and that was after you'd done all the preliminary trials so it was just when you actually were trying to prove it actually worked. Wow. Now, we're in week nine of this course. There are a lot of people in the course probably who've made it to this point who probably aren't anti-vaccination types, I think. And so they're probably thinking about this fairly critically and they might be fairly willing to just dismiss the claims of anti-vaccination groups and so on just outright or call people silly or fanatical. What we're trying to do in this course is to prevent them from doing that to get them to think why people might believe in these sorts of things. Any thoughts about what drives people who don't want to vaccinate their children? Well, one very simple consideration is that if we don't have any polio in this country and we don't in Australia, we haven't had polio in this country for many years then why should my child have a vaccine to protect them against a disease which doesn't exist in this country? After all, the vaccine has a very slight risk associated with it and there is no risk of the disease. What people, of course, forget is that their children, when they grow up are likely to go off to parts of the world where the infection still does exist and it's a bit late to get the vaccine after you've already got the infection. So that's one reason it's not really a problem anymore. In the old days, people used to rush to get vaccines. The polio vaccine was fought for when it first became available in the 1950s in the United States because there was an epidemic of polio every second year and people died and people became paralysed and everybody knew what polio was. But now, the next generation of mothers and fathers don't actually see polio anymore so they don't see a risk. There's a second group that say, okay, well, if everybody else is vaccinated I don't need to get my kid vaccinated and, of course, that's quite correct because if there's no way of the infection spreading for example, if everybody's vaccinated against measles, except me, I'm fine. But what they forget is that if only 99 out of every 100 people are vaccinated against measles, that's still enough to allow an epidemic to occur because every one person who gets infected will infect potentially 100 others and if 99 are protected they won't get it but the other one will and will pass the infection on so all the people who are not immunized will be at risk. So that's a second reason which is not a particularly good one but you can understand why people think that especially for infections which are not as infectious as measles measles is incredibly infectious but most infections are not that infectious. The third reason why people think that is that they've listened to somebody who's had supposedly an adverse reaction to a vaccine. They're persuaded by their neighbour saying when my little kid got it then he had convulsions afterwards. Now, that's a rare complication of measles vaccine for example quite often the febrile convulsions turn out to be occurring with or without the vaccine but the story gets around Mrs Smith's daughter got into real trouble after vaccination and wouldn't it be better just not to be vaccinated? Those people are persuaded very rapidly when an epidemic of the infection occurs for example with the Wipinkoffin epidemics we've had recently that their kid should really ought to be vaccinated but it takes the infection to do it and then there's a small group of people who basically just have a set of disbeliefs about how the world works they don't believe in the infectious nature of disease for example they have an animistic approach to how people get disease it's punishment from God or it's against my religion or whatever and they just have these fixed beliefs and by and large they stay fixed. You've mentioned that one of the reasons that people tend not to immunise their children is like you said there isn't polio in the country but if there was it would obviously people would be flocking to be vaccinated can you paint a picture as to what some of these things look like polio and measles and so on for people who aren't in the cloud? Measles in most people's minds is just a spotty skin disease and for many people who get measles that's all it is but one in a thousand will get a serious internal complication and one in a hundred thousand will be left with major brain damage as a result of measles infection so that the unlucky one is not a trivial disease and in fact more people die worldwide of measles than of any other infection apart from diarrheal disease it's quite a significant problem particularly for young kids indeed that's why we push to get kids vaccinated as early as possible in the developing world because the risk of measles killing you is greatest when you're between the ages of zero and two polio well for 99 people out of 100 polio is a diarrheal illness which goes away after a couple of days but for one in a hundred people it leads to paralysis maybe of a leg or an arm if you're really unlucky it paralyzes your vocal muscles and of course the paralysis is permanent because the nerves that work these muscles are destroyed by the virus so that's why people used to end up on respirators for the whole of their lives because they were basically left unable to breathe for themselves another vaccine that I've been involved with of course is the vaccine for cervical cancer and again the virus that causes the cancer for 98 people out of 100 it's a trivial infection they never know they've had it but for the 2% of people that get persisting in infection they can go on and get a cancer which will kill them and if it's not detected early enough it's a lethal infection in fact papillomavirus kills more people worldwide quarter of a million people worldwide die every year as a result of papillomavirus infection so that's a very significant burden it's the ninth commonest cause of infectious disease death I was looking online at some of the claims by anti-vaccination groups and one group in particular in the US was looking at one of the I think it was a cervical cancer vaccine that you developed and said that people died as a result during the clinical trial how would you respond to them? Yes well judicial watch have been pushing that story for a while what they do is they take the data from the clinical trials and say there were deaths in the people that were immunized there were also deaths in the people who received the placebo these deaths were assessed by the clinicians who were running the trial as not in any way associated with the vaccine people die unfortunately all the time these vaccines were given to teenage and young women and teenage and young women occasionally commit suicide they occasionally are involved in lethal car accidents and they occasionally have other completely unrelated illnesses and there was no difference between the placebo groups and the vaccine groups so judicial watch can reasonably claim that yes there were deaths in the people who received the vaccine and I would have countered by saying yes equally there were deaths in the people who received the placebo and nobody thought that the deaths were connected with the vaccination process Sure Now what sort of role does the media play which is tricky I mean it we've been looking at a bunch of other issues in terms of climate change in terms of all sorts of claims that are made paranormal and everything else does the media play a large role when it comes to anti-vaccination? Yeah look the media play a good role and sometimes a less good role they get the story out there that a vaccine is available the direct evidence of that is that we're doing research on the herpes vaccine at the moment and there have been a bit of media coverage for that and that results in perhaps 5 to 10 emails a day to me to say when will this herpes vaccine be available so obviously everybody is now aware that people are working on the vaccine for herpes and when somebody claims that they have had a bad reaction to the vaccine it's sensation with stuff and the media cluster around and the story gains credence by the fact that more and more media get involved with it and the person responds appropriately to that by making their symptoms worse and worse and then of course the story goes global goes viral to use the current expression although that's not right for a vaccine I don't think and the net result is of course that the things get out of hand but what happened and the consequence of that with the cervical cancer vaccine was that India cancelled its entire vaccination program for the single cancer that kills more women than any other in India simply because there were 4 deaths which were attributable and the media picked up on it the Hindu times decided this was a political issue and that it went viral in India and eventually the government intervened and said that we can't have this much bad reaction even though there was no justification for it so they just cancelled the programs so what is the best counter what's the best way I think to that you can think of I mean you've had a lot of experience with information campaigns and education what do you think is the most effective to try to get as many people to immunize as possible given the in the face of this sort of blatant disregard for the evidence well there's 2 different approaches that are needed in countries where the problem is common and vaccines are there for being newly introduced to get rid of a problem then simple word of mouth works extraordinarily well everybody knows somebody who's had the infection and if you come along and say we've got a vaccine and it's safe and particularly if that message comes from within the community from the district nurses or health workers that are known to the people the vaccine will be accepted and that's usually sufficient in the developed world when you're introducing a new vaccine for something which people haven't really seen as a problem or don't think that they are at a particular risk of then there are 2 important bits one is that you start early with an education program before the vaccine becomes available you get people used to the idea let them ask the questions and make sure that you don't cover up stories that have been spreading around and make sure that everybody does get the information but you produce booklets like this one which basically explain the facts behind the story as well in a way that people can understand and again word of mouth is important if the doctor recommends it, if the district nurse recommends it if the midwife recommends the vaccine then the chances are the mother will accept it and you've got to also accept that some people don't want to be vaccinated that's the right you never say you must be vaccinated you say you should be vaccinated because that's the best way to do it okay this is a question that we ask each of our guests on in think 101 the title of the course is the science of everyday thinking given your career, given your experience in vaccination and immunology and so on what advice do you have for the students, the 60,000 80,000 students who are taking the course to improve their everyday thinking I think that basically the more educated people are the more likely they are to make correct decisions about things you can never have too much education even if you're not going to be a scientist if you're not going to go out there and do experiments understanding the scientific process the fact that you can make a hypothesis or call it a guess if you like and then test it and then at the end of the testing you're reasonably confident about whether your guess was correct or not that is the basis for making decisions about things that you don't leave people with so that even if they don't do the experiments they should be aware that when data are gathered through experimentation it is actually testing an idea and it can be falsified you can get an answer that says your hypothesis was wrong the alternative is straight guesswork don't bother doing the experiment let's just say I'm right and then you get an answer and that's not an uncommon approach to things but it does lead to some very interesting mistakes the important thing is to say that wherever possible test the hypothesis one of the issues that we're dealing with in the course is the idea of cancer clusters so these are quite common we even had a case I think in 2006 in Brisbane if you had much experience do you know the phenomenon or why they tend to pop up when I sat on the international agency for cancer research scientific advisory board for a few years this was one of the topics that used to come up regularly it related to use of mobile phones it related to stuff being discharged from factories some cancer clusters are very real environmental pollutants can produce a cancer cluster and sometimes those cancer clusters are the first evidence of the particular chemical that can cause a cancer mini-matter disease for example is an example where toxic pollution produced a whole swathe of cancers and then the Bhopal disaster as well where there was a release of methyl cyanide I think it was into the environment and that produced a whole cluster of cancers but most of the clusters that people are worried about that mobile phone tower this particular power station there are half a dozen cancers or ten cancers in the community and somebody says that's a cluster rare events occur rarely but they do occur and if you've got a population of 7 billion and you're sensitized to looking for clusters you'll find them and you'll find them with just the probability that you would expect if it's all random in other words, a statistical analysis plus a close look to see if it really is a cluster because quite commonly what you find is they say well we've got six cancers but it turns out that they're all quite different and they're not really a cluster of anything but six people who were unfortunate to get a disease so that it's partly statistics and partly common sense but you just have to remember that people do get struck by lightning every now and then and cancer clusters are in the sort of struck by lightning mode one in a million chance but it does happen My name is Ian I think about infections