Health and medicine
- What is the flu?
- Catching and spreading the flu
- When flu viruses attack!
- Three types of flu
- Naming the flu: H-something, N-something
- Testing for the flu
- Antiviral drugs for the flu
- Genetic shift in flu
- Flu vaccine efficacy
- Flu shift and drift
- Two flu vaccines (TIV and LAIV)
- Flu vaccine risks and benefits
- Making flu vaccine each year
- 5 common flu vaccine excuses
- Vaccines and the autism myth - part 1
- Vaccines and the autism myth - part 2
- Flu surveillance
The infamous Wakefield study kickstarted the Autism Myth, but many studies have since shown that there is no link between the MMR Vaccine and autism. Find out how it all got started. Rishi is a pediatric infectious disease physician and works at Khan Academy. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Rishi Desai.
Want to join the conversation?
- Is there a relationship between the mercury and/or aluminum used as preservatives that can cause disconnects in the electrochemical functions of nerve cells in the brain? There are other studies, I am sure that discuss the heavy metal aspects of inflammation and disruptions of using the mercury and aluminum in vaccines since the mercury based thermosal has been banned in USA from human vaccines (but not animal vaccines which leaves bioaccummulation still can be effect possibilities).(7 votes)
- Yes, there is a relationship. The amount of mercury used in vaccines has steadily declined over the last 15 years, due to improved manufacturing methods. Over this same time period, the rate of autism has increased. Therefore, it appears the the presence of mercury in childhood vaccines protects children against autism.
OK, I'm joking to make a point. While it's true that mercury has decreased while autism has increased, to ascribe causation to this relationship is a fallacy ... the same kind of fallacy that lead to this myth in the first place.(32 votes)
- Do some people still belive in the Wakefield study?(5 votes)
- As is said at9:34in this video, no one really believes it anymore. No one, that is, except for people who willfully ignore the evidence (conspiracy theorist types, mostly).(8 votes)
- Here are other videos on the same topic that I find very well explained :
In the description of the videos you can find links that will send you to a website where you can download the scientific articles mentioned in the videos !
I hope you find them helpful ! :))(5 votes)
- Why do people think that autism is a side-effect of a vaccine?(3 votes)
- There is one acknowledged way that a vaccine can cause autism and that is when a person has an underlying mitochondrial disease. Google "CDC Chief Admits that Vaccines Trigger Autism" and you'll see the former head of the CDC acknowledge this on CNN. Mitoaction dot org estimates mitochondrial disease is about 1 in 4000.
This is just one subgroup of people who may respond with autism when vaccinated; more subgroups are showing up if you look at the latest research.(3 votes)
- @2:02it said measles what is measles?(2 votes)
Measles is a virus that causes fever, cough and a rash most of the time, however, 1/1000 affected people die. The vaccine that prevents measles and is over 93% effective at preventing measles was associated by one doctor as causing autism. The doctor's research was shown to be flawed and no other research supported his flawed findings. Despite this, some people continue to refuse to vaccinate their children. As a result, measles keeps flaring up in the US, as it is now present in Washington and Oregon.(3 votes)
- At0:56, why are the children taken from the UK?(2 votes)
- Your question is confusing. Children were not TAKEN from the UK; they were taken to a hospital in the UK. Unless you mean, why were the children in the study from the UK? That was where Dr. Andrew Wakefield, the discredited main author of the study, practiced.(2 votes)
- When this rumour was in the air,did people research on other vaccines as well or only the MMR?(2 votes)
So for the last 20, 30 years, we've noticed this increase in autism. I'm actually going to quickly sketch out a graph to show you what I mean. We have autism rates over here. And if you follow them over time, basically what happens is that you see that things are going upwards. And the main reason that people cite is awareness. They say, well, if more parents and families are aware of autism because we talk about it more nowadays, then of course, they're going to bring it up with their doctors and it's going to get diagnosed. And although that may be one reason for the increase, people have been searching for other reasons to explain the increase as well. Now in 1998, there was a team of doctors and researchers that put together a study, a study that we call the Wakefield Study. It's named after the main author, which was a guy named Dr. Wakefield. He was a surgeon working in England. And, in total there were 13 people, 13 authors on this study. So this study was done in the United Kingdom, the UK. And what they did is they took 12 children, and these children came into the hospital, reportedly the normal way, the routine way that children come into the hospital. They weren't recruited. And he found that they had developmental problems. So these are 12 children with some sort of developmental problem or delay, and the most common example of a developmental problem among these kids was autism. So a lot of these kids ended up having a diagnosis of autism. And what they did-- I'm actually going to sketch out for you. So let's imagine that this is the head of one of our children. What he asked them was, do they have any symptoms? When did their symptoms start? All of these kinds of things to get at their history, their medical history. And a lot of the families said, well, you know, we remember them having these symptoms of autism, which I'm drawing as a grayed-out brain, and there seems to be-- this is the parents talking now. They felt like there was some sort of relationship with the vaccine. They felt like they remembered the vaccine, specifically the MMR vaccine, the measles, mumps, rubella vaccine, around the time that symptoms began, and that's what he reported. So we actually have now a relationship based in terms of parents' recollection between the vaccine and autism. But what this study was mainly about was actually the gut. So he was a surgeon and he wanted to look at the intestines of these kids and he noticed that on the intestinal biopsies-- when you actually got a little bit of tissue from these intestines-- a lot of them had inflammation. That was what his paper was primarily about, was this inflammation that he saw. So he proposed-- and this is a big deal. He proposed that vaccine was causing this inflammation. He thought that was the cause of the inflammation, and he then thought that perhaps there was some mystery protein-- let's say this blue little protein-- that maybe you take in through your diet, that now, because it's inflamed, can get across the gut and can affect the developing brain. So this was how he proposed there could be a link between the vaccine and autism. Now when the Wakefield Study first came out in 1998, you can imagine the kind of excitement this created for a lot of parents and families that had been for years looking for something to explain why their kid had autism. And so, finally, people could circle this and say, ah, maybe it was the vaccine that caused autism, and that's what people thought. But there were a couple of problems with this idea. The first problem was that some of the patients that had autism symptoms, they actually reported that they were having these symptoms before they had any of the gut symptoms. Now think about that. If you're having autism symptoms before gut symptoms, not after, then that really goes against this theory, because this theory is based around the idea that it's the gut that comes first. So immediately, this is one concern and a big question mark over here whether this is really true. Another question mark is around this mystery protein. I'll put it up here. So this mystery protein-- this is something that Wakefield never really identified. He never said, well, I think it's this protein or that one. And in the last 15 plus years, nobody's found any mystery proteins that would explain what Wakefield was suggesting. So the fact that nobody can actually find these proteins is also another big question-mark. Nevertheless, a lot of studies started getting done. People started saying, well, if there truly is a relationship between vaccines and autism, then let's explore that further. So a group of studies were done around MMR vaccine rates. How often in a population do you actually see people getting the MMR vaccine? And you'd imagine that if there truly is a link between vaccine causing autism-- if that's true, then, of course, the vaccine rates must be going up. That would explain the autism going up. And so they actually looked in a few different places, and, of course, the first place to talk about it is the UK, because, of course, this study was initially done in the UK. And in the UK, they looked over six years, and they found that, actually, MMR vaccine rates had been steady. There had not been an increase. So already this is a little weird if we're thinking that the vaccine is causing autism. You'd expect something different. So they looked again. They actually looked another time. This time they actually looked in the US. And in the United States they did this study over 15 years. And over 15 years, the same thing, steady vaccine rates even though autism rates were going up. Now another study was actually done, this time in Canada and, surprisingly, in Canada it turns out that the vaccine rates were actually going down slightly. So vaccine rates over 12 years now went down, even though autism rates were going up. So this data is done at the population level, but it really does go against this idea that vaccine is causing autism. But people weren't satisfied with that. They wanted more specific research to be done on this mechanism that Dr. Wakefield proposed. So another study was done. It actually was done in the United Kingdom, and this study looked at 473 autistic children. So remember, the initial study was done on 12 children, and now we're looking at hundreds of children with autism, and among these 473, they actually wanted to figure out this part of it. They said, is there a link between vaccine and any sort of gut inflammation and the answer was a resounding no. There doesn't seem to be any relationship in autistic kids with vaccine, MMR vaccine and inflammation of the gut. So that was actually very detrimental to Wakefield's theory. But what about the second part, the second link between gut inflammation and any sort of autism, this part right here? Well, again, another study in the UK looking this time at 262 autistic children found that there was no link between these two things. So gut inflammation and autism did not seem to be related at all. So now the two important components of Wakefield's idea didn't seem to bear out. And then I should also just cross this off, this mystery protein bit, because, again, people have been looking for that, and no one seemed to find that. But that wasn't good enough because you could say, well, maybe there still is some link between vaccine and autism, but maybe this mechanism wasn't quite right. So research got done on this purple arrow over here. So they said, OK, what about this? Could it be possible that there's a link between the two using some other mechanism. And so a study was done in the UK, specifically looking at MMR vaccine and autism. Is there a relationship? And it turns out that they, in this study, looked at 71 autistic children, and they found that among these children there was no relationship. And this study was actually in a way done again. In fact, in another setting done in a different way, but also trying to answer the same question of a link between vaccine and autism in Finland this time. They found that among 309 autistic children, there was no link. Now, remember this link that we created was done among 12 children and now we have hundreds and hundreds of kids in different countries. Another one was done in the US. And all these studies are finding the same result, that basically there were no links that they could find between vaccine and autism. And so people started really doubting the truth behind that very first study, that first study done on 12 kids. But people were still talking about it and said, you know, what about that Wakefield Study? Isn't it possible that there could still be a link in spite of all this other evidence? So, finally, a group out of Finland tried to do another type of study, a different approach, that they thought would conclusively answer the question. They basically said, well fine. Why don't we follow 1.8 million children. So obviously this is many, many children that are getting vaccinated and just follow them over time and see if they develop autism, and this might answer once and for all whether there's a link. And so they followed these kids over time, and they found a grand total of zero cases of vaccine-associated autism. So in all these cases of vaccination, none of them resulted in autism. So at this point, people really stopped believing the study, the Wakefield Study, and whether there was any link. That was kind of resolved. All of these studies said, no, there was really no link between vaccine and autism, but a question remained around the Wakefield Study and how those results were found in the first place. I'm actually going to pause right there and we'll jump into that in the next video.