Wednesday, September 30, 2009

Confidence in probability

In an incredible stroke of bad luck this week Natalie Morton (aged 14) died shortly after receiving a cervical cancer vaccine; quite rightly the story has been picked up by the press and widely publicised however I can't help thinking that the attention will cause more harm than good. Clearly this is a human tragedy and as a parent myself I feel deeply sad for Natalie's parents and family, as I'm sure anyone would. However we must also remember that cervical cancer is no walk in the park either, so I am torn between wanting to acknowledge the loss and yet afraid that all this publicity will wreck a really promising and successful campaign of immunisation for millions of young women.



This vaccine has already been given successfully to millions of girls all over the world, however it is not without it's critics; in the USA there has been a backlash from Christian groups who have boycotted it because they believe it encourages promiscuity. Several religious groups in the UK have campaigned against it too, however I think our Government made the right choice, mainly because the principal of prejudicing the health of a child because of the religious beliefs of the parent seems morally reprehensible to me.

In terms of safety this is a very safe vaccination, in fact over the course of our own UK programme the number of adverse reactions so far has been 4657 out of 1.4 million doses or 0.33%, that's a probability of 1 chance in every 300 jabs that someone may suffer a mild headache or a sore arm. To put this into perspective the probability of being involved in a car accident in the UK is roughly 0.38% (2007) i.e. slightly higher.

Interestingly it turns out that the likelihood Natalie died as a direct result of this jab is diminishing fast. We learn today that she unfortunately had a serious underlying medical condition anyway; however I fear the damage has already been done.

I do hope the various religious groups don't now jump on the "safety" bandwagon in an attempt to salvage their own agenda's, we shall see.

10 comments:

Lisa said...

Steve, I'm going to jump on the safety bandwagon myself!

Cervical cancer kills less than 4000 women a year in the US, and not all of those deaths will be prevented by the current HPV vaccines. The claim is that it will stop 70% of those cancers, so let's use that although I suspect the figure is too high: at 2800 deaths prevented, it's extremely rare to die from cervical cancer.

There are about 153 million women in the US, so vax complications at the rate of 0.33% (assuming they all get the jabs, and assuming the rate of side effects is correct) means about half a million women will have side effects. Side effects are admittedly often headaches, but seizures are also common side effects, and there's been a lot of reports of neuropathies and paralysis as well with gardasil, and of course these publicised deaths.

And of course the vax has only been tested for four years, so we have no idea what happens after that. Maybe the immunity of those women will wane and they will have to risk side effects again by having another jab, or maybe they will go on to contract cervical cancer.

The VAERS database in the US shows 47 reported deaths for HPV vax, this database is generally thought to represent between 10-30% of actual side effects, since most are unreported in the national database.

Cervical cancers are slow growing cancers, and pap smears/tests have reduced them by about 75%, and the number of them has been continuing to decrease annually. The remaining cases happen disproportionately to smokers (2x more likely to get this cancer than a nonsmoker) and women who have never had a pap test or cervical screening. I'd rather spend the billions this jab makes for Merck and GSK on making sure *all* women get proper cervical screening, since that doesn't have any side effects or deaths. At least I haven't heard of anyone dying from a cervical smear. ;-)

Those profits are due to double, by the way, as boys will be getting the jabs soon too. Eventually we'll be paying the pharmaceutical companies hundreds of millions of dollars per life saved.

And lastly, that BBC story reeks of blatant propaganda. They're not confirming the which illness she had, and of course they'll say it's premature because they're waiting for tests, but they didn't think it was premature to get a news article out there saying that the death was NOT caused by the vaccine. Call me sceptical, but releasing a story like that when you can't even yet confirm the illness sounds like someone is trying to manipulate, and anyway I don't believe that healthy 14 year old girls who have a vaccine and then die have such a serious underlying medical problem that no one had any inkling of it before she got the jab. How many other girls might have these dreaded unknown serious medical conditions that never make an appearance until there is an interest in explaining their death following a new jab?

Incidentally, this type of response has been typical of the health authorities each time a young girl has this jab and then dies. I've seen it in cases in the US and Canada. The coincidence is a little too much for me.

There is NO WAY I would let a daughter of mine get cervarix or gardasil yet. I'd rather wait to see how these serious underlying conditions pan out over time and do pap smears. In the meanwhile, I'll gladly take the cervical cancer odds whilst I watch the billions in profits headed to GSK and Merck to save relatively few lives.

Elizabeth said...

My daughter had Gardasil a few years ago. It protects against genital warts too -- the one they give in UK schools -- Cervarix -- doesn't. And yes, let's get the boys done too.

Steve Borthwick said...

Hi Lisa, thanks for such a detailed reply.

I must admit, I find this whole subject fraught with complexity because of all the different dimensions involved; plus the decisions directly affect our most important assets i.e. our kids (I have a 6 & 8yr old, hence the interest in this)

- I think it's entirely appropriate to call out the small (relatively) number of deaths from these types of cancer but there are also a very large number of cases that don't necessarily cause death but are still unpleasant and contagious, last I read that number is at least in the tens of thousands in the USA.

- I hate the idea of being subservient to the selfish priorities of big-pharma too, but it's the crappy system we have and as a society we seem to be unwilling to alter it; I really wish this kind of developmental R&D happened without a primary profit motive.

- I should have been more explicit in the post, but perhaps my real fear is that vaccinations in general will be tarnished because of this, like MMR and that whole fiasco; it's a complicated thing and our media is not good at conveying complicated things to the general public.

- I think we could all take the approach of "wait and see", the problem then I fear is that everyone will take that approach, then the risks of future epidemics will go up and not down. At some point you have to say the licensing process is safe (its never 100% of course) or it isn't and change it etc.

Tricky stuff..

mel said...

I have to agree with Steve here.

It's not just the number of deaths we should be concerned with, but the net effects of the disease versus the vaccine.

We don't know yet how many deaths will be caused by the vaccine, but it's surely safe to say that in general the side effects will be less unpleasant than the cancer.

I don't think the BBC did anything wrong. Initial reports implied the girl had died because of the vaccine. If it turns out to be false, it's surely their duty to report this?

Steve Borthwick said...

Hi mel,

It's a tough one, I agree the BBC haven't done anything wrong in reporting the follow-up about the underlying medical condition of this girl, I think my concern is that the damage has already been done and this story will be less widely publicised than the original one, although perhaps not on the BBC. There isn't an obvious answer to this, clearly it's not in anyone's interests to suppress anything but then again if the information is not used objectively we all potentially suffer from the resultant increased outbreaks, as we have seen from the MMR example.

Interestingly, I offered all of the employees in my company a free seasonal flu jab this year; only 5 out of 20 wanted it, vaccinations generally seem to be feared, I think that's a bit scary.

Lisa said...

I think a big part of the unwillingness to alter the drug system stems in part from the public's willingness to assume that the approval process is safe without really knowing much (if anything) about it or asking any questions.

I watched a lot of my friends that were in med school get thrown out of drug studies because the company who was doing the study didn't like the side effect they developed, so they just got rid of them. There have been a lot of atrocities that pharmaceutical companies have been caught perpetrating in the last twenty years, and it's really horrible stuff. But the public's memory is short, the desire to trust is irresistable, and medicine is not seen as the business endeavour that it truly is.

Drug licensing is far from safe. There was a study in JAMA ten years ago that showed that more than 100,000 patients in hospital died in a year from adverse reactions to properly prescribed and dosed medicines (well, properly prescribed from the point of view of drug company studies and FDA recommendations anyway). That means that whilst heart disease, stroke, cancers and pneumonia claim more lives, prescription drugs are next on the list as the number 5 killer. It certainly puts cervical cancer deaths in perspective.

If only we could set the pharmaceutical companies at solving this problem! ;-)

Lisa said...

Hi Mel,

I completely agree that IF it turns out to be false, BBC *should* report that. IF and WHEN. Not before. If they don't actually know what the serious underlying medical condition is, such that they can say, I'd say it's premature to report that something is true, and we should just trust them on it.

Chairman Bill said...

The thing we're missing here is that there at x thousand deaths from HPV PER YEAR. The risks from the jab occur just once.

Steve Borthwick said...

I hear today she had a tumour in her chest and could have died at any point (it was reported on the BBC).

Good point CB.

Lisa said...

That is a good point about lifetime risk of cervical cancer. A better assessment of the risk from the vax is 3x the short term risks for the three doses, plus whatever longer term risks there are, if any. We don't know how long immunity lasts, or what the long term effects are because this vax wasn't tested very long. Once we learn how long the immunity lasts there may be many more doses recommended every so often, but hopefully not.

This girl did indeed have some serious bad luck - to have a large tumour in her chest with no symptoms such that nothing could have been done was unusual and certainly extremely unlucky. I wonder what the problem was with saying "tumour" instead of serious underlying medical condition. And you don't need tests to diagnose a tumour.