Question 3 (Probably)

Hello again,

I’ve just put up the third question (although have managed to confusingly call it Question 2!) on YouTube

I still seem to be performing my excellent party trick of moving my mouth seconds before I say anything!

The question concerns the use of ‘probability’ as the basis of science research. When responding to it, don’t get bogged down in the mathematical concept of Probability Theory (that’s something that only mathematicians with the brains the size of plants understand). I really want you to consider the wider implications of using methods and analyses that are tested against the probability that experimental outcomes are simply random. These days 95% (or more properly expressed 0.05) seems to be the ‘magic number’ for significance. In other words there is only a 5% chance that the observed difference between the experiment and the control was a fluke. You might like to think why 94% should not be significant…and let me know. The choice of significance level is down to the researcher. In biomedical sciences (where lives are at stake) we would expect very high probabilities to be used, say 99.99%. If we were analyzing the results of children’s academic performance (where lives are at stake) we would generally use lower probabilities. We don’t generally go below 95% which means “9 out of 10 cats say the prefer it” isn’t significant. Someone should tell Wiskas (apologies to Canadian students – it’s a famous cat food ad in the UK.)

We can never have 100% probability and the problem of course is that many non-scientists seemingly don’t understand this. Even the most exacting drug trial can only publish a probability that the drug works and/or is safe. This may be ridiculously high, but still may be seen by some (especially in the media) as presenting a risk. After all the researchers have implied that it is not 100% safe! Misunderstanding of science analysis is quickly transferred to a misunderstanding of maths when bottom line probabilities are turned into absolute values. Suddenly hundreds of people are at risk. Such general misunderstanding and deliberate misleading by the media (disasters sell papers) may spark all sorts of safety fears. Tony Blair famously refused to say whether his one year old son was to have the MMR vaccine (he did after a considerable delay) despite the government advocating its safety (

The fact that we operate in a world of probability seems to be confusing to a public that thinks we deal in certainty. If a patient, or a concerned parent, asked you ‘Is this drug 100% safe?’ how would you answer?

This then is the question. Is the MMR or the H1N1 vaccine safe? Start your response definitively – either yes or no, then add something to justify your decision.

I hope you enjoy your discussion.


4 thoughts on “Question 3 (Probably)

  1. …I think that when answering the question “is the MMR vaccine or the H1N1 vaccine safe,” one has to decide how they specifically define “SAFE.” When you think about it, this is basically what probability
    to doing when applied to the testing the safety of drugs, or procedures, or other products. It is putting a number value to the chances of safety and the chances of “unsafety,” or the harms involved
    with whatever is being tested. So for me personally, the research published on the probability of safety of the MMR and the H1N1 has offered numbers that I consider safe. I see the probability of having
    a harmful reaction to a vaccine in the percentage, and feel that the vaccine is “safe,” based on my definition of safe. That said, I can appreciate science’s responsibility to refute 100% probability because
    I understand the foundational paradigm and philosophy behind it.
    Along a similar vein, I think that riding my bike down Broadway Street with my lights and helmet on at night is safe, and I think that eating a scoop of ice cream once a week is safe (some may not agree, so I bet they would consider a probability of 95% as being unsafe).
    It seems to me that one of science’s difficulties is bridging the gap between the objective symbolism and interpretation of numbers, and the correlating data that is subjective in nature, like the concept of safety. I think that science can offer the numbers, caution people that the idea of safety is subjective and up for them to decide, as informed consumers. With vaccinations in particular, one has to consider herd immunity, and the “safety” that provides populations. When the immunity of groups is involved, and every individual has a certain percentage of having a harmful result of a vaccination, how
    does that translate into overall probability of the group? Likewise, what is the overall definition or belief of ‘safety’ with all those people? It seems that an important thing to consider would be a qualitative study involving personal interviews with people, to get their definition of safe related to the MMR and H1N1 vaccine. We would hope people have informed decisions, and not all depending on Mrs. Blair to tell them what to do.

  2. Yes, I believe the H1N1 shot is safe.

    I (Jayne) just got the H1N1 shot and I didn’t get it because I believe it will 100% protect me against H1N1, but because it decreases the chance or possibility of getting it. I don’t think one can ever expect anything to be certain in this world, and I think that’s a reality we as humans have come to realize and accept. I wake up in the morning to go to school, I am not certain that I will make it to school on time, or even make it to school at all. My alarm can malfunction, my breakfast can burn, my bus can be late, I might find out I have something more important than school that I have to tend to last minute, I might get sick before I step out of the door etc. Those are all very possible things that could happen to me. From my experience, the probability for a bus to be late is at least 50%, breakfast burning is at least 25%, and if you mathematically calculate the probability of a student making it to school on time after taking all these factors into consideration, the probability would be close to 0%. Yet, I make it to school on time almost all the time. Another example involves the good old Motrin (Ibuprofen), it says on the bottle “For fast and effective relief of headache pain including moderate migraine and tension headache, menstrual pain, dental pain, and pain associated with arthritis, inflammation, muscles, bones and joints, sprains or strains etc. On the other side of the bottle is a list equally long which indicates the cautions, “Ibuprofen may cause a severe allergic reaction that could include wheezing, facial swelling, hives, shortness of breath, shock or a fast irregular heartbeat.” And many times, there is a high chance that ibuprofen will not be able to get rid of a headache. Yet most people still take them, and many on a regular basis. I take it because I know the probability of this drug taking care of my pain is higher than the probability of this drug giving me irregular heartbeat. I know this from past experiences, but it doesn’t mean this will always be the case in the future. But to me, the advantages of taking this drug at the moment weigh heavier than its disadvantages. I think that’s how I feel about the H1N1 shot; of course there are risks with any kind of medical treatment, but the risk that the H1N1 vaccine reduces weighs more than the risk it poses.

    I (Rebecca) agree with Jayne. I have benifited from previous vaccines and not been seriously affected as I could have been without it. I agree with Jayne that there are arenas of pobability surrounding us in our every day lives. Neither can we predict to some degree that the probability of me attending school at 7am will be the same predicted percentage than at 8.50am with ten minutes to spare. All probability is based on fact at the time it is calculated. And at the time that i have decided to have a vacine for any virus is a calculated one. i obtain all the facts and figures and then predict whether this vaccine will help me. The same as i have done for the new swine flu vaccine. Which i have not taken due to the lack of research surrounding the testing of its effectiveness. Especially in its ability to affect my diabties and d-stabalise my present condition whilst doing a very large amount of work for university. So i Conclude that there is alot more to consider morally with decisions on vaccination.

  3. I (Imogen) think that to be able to answer this question you have to be able to define ‘safe’ in your own mind, in some peoples case this may mean unless nothing adverse has happened, then yes it is safe, others may feel differently. It is also important to take into account your personal situation, whether this is your health or lifestyle. An example of this is the H1N1 vaccine. If you have serious health problems that mean if you catch the virus it may make you seriously ill, it could mean that prevention is the best step. This is also apparent is you perhaps are a doctor and are in contact with several ill people. All drugs come with a list of possible side effects and the chances of them happening are pretty low, however in the past year I (Imogen) have had several types of antibiotics, most which have caused adverse effects due to allergic reactions. Even though this has happened, at the time I still tried them as I needed a cure and I would rather try to become better than suffer. What I am trying to say is that it is morally a persons decision if they should have a vaccine and deem it ‘safe’ or ‘unsafe’. In my personal experience I do deem vaccinations and drugs as ‘safe’ as the testing of them is so substantial before they are even considered for use that the probability of an adverse reaction is unlikely, however, as scientists you can never be 100% sure that they are definitely ‘safe’.

    I (Rebecca) somewhat agree with Imogen’s viewpoint on how getting vaccines should be a personal choice, in that I don’t believe they should be forced on anyone. I do, however, think that in choosing to get vaccinated or not, people need to think beyond themselves. If someone who is relatively healthy decides that they do not want/need to get the vaccine, they must also consider that although their immune system may be able to fight off a severe viral infection, they may inadvertently be a carrier of the virus to others whose immune system is not as strong.
    Although it seems to be human tendency to focus on what can “go wrong” in a situation (like serious side effects of vaccination), and that this is what sells in the media, people need to be aware of where they are getting their information from. Safety and prevention may not be as thrilling on the news as the horrors of a healthy young woman dying from a supposed “cure,” but as health care professionals, I think we should be concerned about how wrongly vaccines are often portrayed, and take it upon ourselves to respectfully educate those around us… (cue me stepping off my soap box now)… 🙂

  4. MMR is the safest way to protect children against measles, mumps and rubella and is effectively used in over 90 countries worldwide. According to The World Health Organisation (2001) MMR is a highly effective vaccine with an outstanding safety record.

    The problem with ant scientific evidence is it cannot be 100% safe and the media use this in its favour to scare monger. With all vaccines and medication there will always be an element of risk as we are all different and our bodies react differently to different substances.

    We agree that the MMR vaccine is likely very necessary and likely very safe…but we understand it is all a question of probabilities and odds, with the odds heavily favouring vaccination. But we should remain open-minded and we rarely like to think of ideas in absolute.

    We do agree that the public does associate safety with 100% certainty, though we think that this is changing. We do not believe the public takes what the health community says at face value anymore. We think we are under much greater scrutiny in this age of rapid and abundant communication.

    As parents we feel we should be given the facts about both the vaccination and the disease it is protecting against so we are able to make an informed choice about vaccinations.

    As to whether Tony Blair should have gone public about his son having the MMR vaccine, we don’t feel this is really an important issue, we feel the media should stop worrying about the private lives of our politicians and concentrate on giving honest facts and not twisting scientific evidence to sell news papers.

    The media attention and the Wakefield report have had a positive effect as more studies and research have been undertaken and so the public have more information. The NHS website quotes:

    The Wakefield et al study published in the Lancet in 1998 actually said ‘We did not prove an association between MMR vaccine and the syndrome described’ and none of the studies since have found a link.

    Berelowitz, one of the contributors to the Wakefield study, has subsequently said ‘I am certainly not aware of any convincing evidence for the hypothesis of a link between MMR and autism…’ (Berelowitz, 2001).

    We believe this issue/question brings up interesting ideas around faith, specifically the faith we all have in modern science; and maybe how this is evolving over time. Is the world in general becoming more sceptical? Is this why we are questioning so much these days?

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