Saturday, 9 November 2013

What Doctors Don't Tell You about MMR safety

According to the bits of What Doctors Don't Tell You that I can access, there is a news story: "MMR causes fevers and fits, US agency admits".  In the interest of fair comment and free speech, here is the story:

The MMR (measles, mumps, rubella) vaccine causes fever and fits in around 2.5 per cent of children vaccinated, a US government agency has admitted.
The most vulnerable age appears to be between 16 and 18 months at the time of vaccination, a group that will suffer “significantly higher” rates of fits and seizures compared to younger children aged between 12 and 15 months.
The US agency, the Centers for Disease Control (CDC), made the discovery when they analysed the records of 840,348 children, aged between 12 and 23 months, who had been given the MMR vaccine between 2001 and 2011. Of these, 18,403 children had a fever within 14 days of being vaccinated, and a further 1,810 suffered a seizure. Together, this represents a rate of around 2.5 per cent.
If there is a hidden agenda to this sudden revelation, it is this: there’s a growing move to have children vaccinated at a later stage, and this is an argument against changing current policy.
(Source: JAMA Pediatrics, 2013, epub ahead of print).
There are some weasel words here so I copy and paste the abstract from the reference for your delectation and delight:

Importance  The first dose of live attenuated measles-containing vaccines is associated with an increased risk of febrile seizures 7 to 10 days following immunization among 12- to 23-month-old children. The combination measles, mumps, rubella, and varicella vaccine is associated with a 2-fold increased risk of febrile seizures 7 to 10 days following immunization compared with the separately administered measles, mumps, and rubella and varicella vaccines. It is unknown whether the magnitude of these increased risks depends on age at immunization.
Objective  To examine the potential modifying effect of age on the risk of fever and seizures following immunization with measles-containing vaccines.
Design, Setting, and Participants  Retrospective cohort study at 8 Vaccine Safety Datalink sites of a total of 840 348 children 12 to 23 months of age who had received a measles-containing vaccine from 2001 through 2011.
Exposures  Any measles-containing vaccines and measles-containing vaccines by type.
Main Outcomes and Measures  Fever and seizure events occurring during a 42-day postimmunization observation period.
Results  In the analysis of any measles-containing vaccines, the increased risk of seizures during the 7- to 10-day risk interval, using the remainder of the observation period as the control interval, was significantly greater among older children (relative risk, 6.5; 95% CI, 5.3-8.1; attributable risk, 9.5 excess cases per 10 000 doses; 95% CI, 7.6-11.5) than among younger children (relative risk, 3.4; 95% CI, 3.0-3.9; attributable risk = 4.0 excess cases per 10 000 doses; 95% CI, 3.4-4.6). The relative risk of postimmunization fever was significantly greater among older children than among younger children; however, its attributable risk was not. In the analysis of vaccine type, measles, mumps, rubella, and varicella vaccine was associated with a 1.4-fold increase in the risk of fever and 2-fold increase in the risk of seizures compared with measles, mumps, and rubella vaccine administered with or without varicella vaccine in both younger and older children.
Conclusions and Relevance  Measles-containing vaccines are associated with a lower increased risk of seizures when administered at 12 to 15 months of age. Findings of this study that focused on safety outcomes highlight the importance of timely immunization of children with the first dose of measles-containing vaccines.

Excuse me for being obtuse, Ms (sorry Dr honoris causa) McTaggart, but isn't a hidden agenda supposed to be, well, hidden.  Not blatantly obvious in the conclusions and relevance section of the abstract.  Oh, and isn't part of the reason for any trend to later immunisation the result of you and your philosophy of pharma is bad, organic farmer is good.

But there is more. First of all there is a video which shows the revelation is a bit less than a revelation, since the lead author says they already knew there were cases of fevers and seizures.  Secondly there is an editorial.  One thing that jumped out of the editorial was this:
The implications of these results are significant.  First, it reinforces the well established safety of the current recommended schedule, which is based on many years of prelicensure and postlicensure safety and effectiveness data, including concomitant use studies.
In other words, MMR is safe and even safer when administered at the correct time. But you wouldn't know it from the WDDTY story because it chooses to highlight the negative. 

But hang on a minute.  Surely the medical profession isn't interested in checking whether what it does is safe or not?  That's the logical conclusion of the claims of the alternative medicine brigade when they tell us that doctors don't tell us about all these wonderful alternative cures.  Surely doctors are not bothered whether you live or die. 

News for the readers of WDDTY: doctors do care whether you live or die.  That's why they went into the profession in the first place.  It takes a long time to qualify and requires much rigorous study.  Much easier, perhaps, to set yourself up as an alternative practitioner and set your own fees.  Much quicker too.  Sometimes you don't need any qualifications.

Back to the MMR vaccine.  News is only news if it is new.  Otherwise it is a reheated soufflĂ©.  So here are some bits of cake going for a spin in the microwave of news, as easily found in a search of PubMed:

Measles-containing vaccines and febrile seizures in children age 4 to 6 years (2012)

Adverse reactions following immunization with MMR vaccine in children at selected provinces of Iran (2011)

Measles-mumps-rubella-varicella combination vaccine and the risk of febrile seizures (2010)

That wasn't difficult to do.  In fact, it was so easy it makes you wonder why the writers at WDDTY, Sid and Doris Bonkers, sorry, Mr & Mrs Hubbard, can't do it for themselves, to see what has already been published and to check their facts

Perhaps the easiest thing of all, since the claim is that the CDC is "admitting" these reactions to the MMR vaccination, is to check what the CDC itself says and when it said it.  For example:
  • The most common adverse events following the MMR vaccine are pain where the vaccine is given, fever, a mild rash, and swollen glands in the cheeks or neck.
Studies have shown a small increased risk of febrile seizures occurs among children who are younger than 7 years old approximately 8-14 days after vaccination for every 3,000-4,000 children vaccinated with MMR vaccine. This is compared to children not vaccinated during the preceding 30 days
And when did they say this:
  • Page last reviewed: May 15, 2010
  • Page last updated: February 7, 2011
So, the headline isn't really true while the figures might be.  But don't let that stand in the way of an antivaccination story.  If it can be spun to make the MMR vaccine look bad then that's the angle to be taken.  And heaven forbid that you comment on the WDDTY Facebook page about it - you'll only get free speeched into the deleted comment bin.

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