Combination MMRV vaccine linked with two-fold risk of seizures

Jun 28, 2010

The combination vaccine for measles, mumps, rubella and chickenpox (MMRV) is associated with double the risk of febrile seizures for 1- to 2-year-old children compared with same-day administration of the separate vaccine for MMR (measles, mumps, rubella) and the varicella (V) vaccine for chicken pox, according to a Kaiser Permanente Division of Research study appearing online in the journal Pediatrics. A febrile seizure is a brief, fever-related convulsion but it does not lead to epilepsy or seizure disorders, researchers explained.

Funded by the U.S. Centers for Disease Control, the study analyzed 459,000 children 12 to 23 months old from numerous health systems across the United States receiving their first dose of measles-containing vaccine and found MMRV to be associated with a two-fold increased risk of fever and febrile seizures 7-10 days after vaccination compared with same-day administration of a separate shot for MMR and the varicella () vaccine. This study found that the risk for a febrile seizure after the first dose of MMRV vaccine is low, although it is higher than after MMR vaccine and varicella vaccine administered as separate injections.

The study found no evidence of an increased febrile seizure risk after any measles vaccine beyond 7-10 days post vaccination.

"Because the risk of febrile seizure is higher for the quadrivalent (combination) vaccine, providers recommending MMRV should communicate to parents that it increases the risk of fever and febrile seizure over that already associated with measles-containing vaccines," said the study's lead investigator Nicola Klein, MD, Ph.D., co-director of the Kaiser Permanente Vaccine Study Center. "But concerned parents should understand that the risk for febrile seizures after any measles-containing vaccine is low: less than 1 febrile seizure per 1,000 injections."

The CDC recently recommended that either vaccine may be used for first dose for 1-2 year olds, however families without a strong preference for MMRV should receive separate MMR +V vaccines, Klein said. The CDC reiterates that providers who consider using MMRV should discuss with families and caregivers the risk and benefits.

"While this study and the resulting CDC recommendations are very important and ones our pediatricians will follow, it is also important to emphasize that it is more common for a child to have a febrile seizure caused by a simple cold than by an immunization. And though febrile seizures are a very scary event for a family, they are not dangerous and do not lead to later epilepsy or ," said Randy Bergen, MD, a Kaiser Permanente pediatrician and infectious disease specialist at Kaiser Permanente-Walnut Creek.

Kaiser Permanente researchers used its electronic health records and Vaccine Safety Datalink data from 2000 to 2008 to assess seizures and fever visits among children aged 12-23 months following MMRV and separate MMR +V. They compared seizure risk following MMRV to MMR +V using regression analyses and by incorporating chart-reviewed febrile seizure cases.

The Vaccine Safety Datalink project is a collaborative effort between CDC's Immunization Safety Office and eight managed care organizations: Kaiser Permanente Northern California, Kaiser Permanente Southern California, Kaiser Permanente Colorado, Kaiser Permanente Northwest, Health Partners, Group Health Cooperative, Marshfield Clinic and Harvard Pilgrim Health Care. The VSD project was established in 1990 to monitor immunization safety and address the gaps in scientific knowledge about rare and serious events following immunization. The VSD shares electronic health records from the organizations' health systems.

MMRV was licensed by the FDA in 2005. MMRV was subsequently recommended by the Advisory Committee on Immunization Practices (ACIP) in 2006. Although prelicensure studies of MMRV among 1-2 year olds noted higher rates of fever and measles-like rash one to two weeks post vaccination when compared with separate MMR + V, it was unknown at the time of MMRV's licensure whether a higher rate of fevers was similarly associated with increased risk of febrile seizures. In February 2008, Kaiser Permanente researchers alerted the ACIP to preliminary evidence of an increased risk of febrile seizures following MMRV. This study represents additional data on twice as many vaccines.

"The Vaccine Safety Datalink, which we used to conduct this study, is a premiere example of how different managed care organizations can leverage their electronic medical records to improve safety and monitoring," Klein said.

This is the latest in a series of Kaiser Permanente studies undertaken to better understand the protective effects and risks of vaccines. Recent published studies found children of parents who refuse vaccines are nine times more likely to get chickenpox and 23 times more likely to get whooping cough compared to fully immunized children. A study published last year found that herpes zoster, also known as shingles, is very rare among children who have been vaccinated against chicken pox. A recent study in the Journal of the American Medical Association found that the pneumococcal vaccination is not associated with a reduced risk of heart attacks or strokes in middle-aged men.

Explore further: Afferent's P2X3 inhibitor shows 75 percent reduction in chronic cough frequency

Related Stories

Vaccines and autism: Many hypotheses, but no correlation

Jan 30, 2009

An extensive new review summarizes the many studies refuting the claim of a link between vaccines and autism. The review, in the February 15, 2009 issue of Clinical Infectious Diseases and now available online, looks at the ...

Recommended for you

Ebola isolation at US base 'pretty much vacation'

2 hours ago

With plenty of flat screen TVs, game nights and even an outdoor fire pit, life in isolation for members of the U.S. military who have returned from the Ebola mission in West Africa can look a lot like summer camp.

Chinese-built Ebola center dedicated in Liberia

6 hours ago

China, one of the first countries to send aid to battle Ebola in West Africa, ramped up the assistance significantly Tuesday by opening a 100-bed treatment center in Liberia as rows of uniformed Chinese army ...

User comments : 10

Adjust slider to filter visible comments by rank

Display comments: newest first

UncleDave
2.3 / 5 (3) Jun 28, 2010
But...but...but...all the studies and Big Pharma say there is no connection between autism/CNS disorders and infant vaccinations, yet here is Kaiser with some evidence!!
CarolinaScotsman
3 / 5 (3) Jun 28, 2010
UncleDave, febrile seizures are in no way related to autism/CSN disorders. One has absolutely nothing to do with the other and trying to link them displays either ignorance of the first order or propaganda scare tactics.
Caliban
2.3 / 5 (3) Jun 28, 2010
@CS

Granted, there is a big difference between autism/CNS disorders on the one hand, and fever/febrile SEIZURES on the other, but at the same time, there has been NO mainstream medical research linking vaccines to any significant negative outcomes. Even the possibility of any such link has been heatedly denied.

There very obviously is a link.

Now, what remains to be established is just what, precisely, the link is -an immuno-response activation, or is it Thimerosol(or other chemical) reaction linked- or some combination?

Immuno-response seems almost certain, due to induced fever, and seizures could be a direct result of hyperfebrility, and/or neurotoxic effect of mercury or other chemical stabilizing agents in the vaccines.

Either way, it is obvious that some changes need to be made. BigPharma shouldn't be let off the safety hook, simply because they made the decision to stockpile a bunch of cheap and dirty vaccine components to increase their profitibility.

yyz
3.7 / 5 (3) Jun 28, 2010
Caliban,

Prior to this study of the MMRV vaccine, MMR vaccines were known to possibly induce febrile seizures in a small percentage of patients. The article notes that "Although prelicensure studies of MMRV among 1-2 year olds noted higher rates of fever and measles-like rash one to two weeks post vaccination when compared with separate MMR + V, it was unknown at the time of MMRV's licensure whether a higher rate of fevers was similarly associated with increased risk of febrile seizures." This study did indeed find an increased risk of febrile seizures with MMRV vaccines. The exact mechanism for this risk is under study. The CDC FAQ page on MMRV vaccine safety is a good starting place for those with questions ( http://www.cdc.go..._qa.html ).
yyz
5 / 5 (1) Jun 28, 2010
Concerning Thimerosal and MMRV and MMR+V vaccines, the CDC notes:

"measles, mumps, and rubella (MMR) vaccines do not and never did contain thimerosal. Varicella[V] (chickenpox), inactivated polio (IPV), and pneumococcal conjugate vaccines have also never contained thimerosal."

Source: http://www.cdc.go...s.html#7
yyz
5 / 5 (1) Jun 28, 2010
As an additional note, from the CDC:

"Varicella[V] vaccine is not known to cause febrile seizures. A study among nearly 90,000 children who received varicella vaccine showed no increased risk of febrile seizures due to varicella vaccine."

Source: http://www.cdc.go...a.html#9
RealScience
5 / 5 (1) Jun 28, 2010
In general a young child would only get one of these diseases at a time, and the immune system would only fight one at a time.
Only occasionally would a child be exposed to two such diseases at once, and three or four would be too rare for evolution to have cared about.
(To be sure, the immune system would often be fighting bacteria in scapes and cuts, but that is quite a different battle.)

So why do we give three and now four vaccines at once?
Sure, it is more convenient for the adults, but giving four seperate shots is not that big a deal.

Vaccinations are in general a good thing, but the immune system is very complex and giving a child several vaccines at the same time is asking for trouble.
Caliban
2.3 / 5 (3) Jun 29, 2010
@yyz,
Right- so I was speaking rather loosely, and you were right to set the record straight.
Having said that, however, I must also point out that you spoke to only a portion of the record, and, regardless of the findings of the CDC, the effort has been made to deny and or downplay the possibility of a link between vaccines and various negative effects induced by them.

Sorry to over-generalize, but the fact remains. Have a quick look at this table, and you will see that a quite significant number of vaccines(as currently formulated) contain thimerosal. I won't make any claims as to the harm potential of other components. Please note that the formulations are as of 2010. One can't be too sure of formulation 3,4,5, years ago:

http://www.vaccin...able.htm

I agree with RealScience, and I believe, you as well, that vaccines are a good thing. But I think you'll also agree that any possibility of collateral harm should be taken very seriously indeed.
yyz
not rated yet Jun 29, 2010
@Caliban:

After reading your post wrt thimerosal and MMR and MMRV vaccines I wasn't sure if you might be aligned with the antivax crowd (glad to see you're not) and I wanted to clear up that widely held misconception. I harbor strong doubts that thimerosal is of consequence to 99.8% of the population (allergic reactions are generally mild), but that said, thimerosal was taken out of childhood vaccines in 2001 (see the link to the CDC thimerosal FAQ page above). While I do agree with you that more research is needed into serious side effects from vaccines, I worry that misinformed or uninformed parents opting to skip vaccinations altogether put not just their own children at risk, but also those who are too young and/or ill for vaccinations. The (wholly preventable) rise of tragic diseases from our past, like polio, pertussis, smallpox, etc, serves as a wake-up call that vaccinations need to be taken very seriously too.
yyz
not rated yet Jun 29, 2010
Two recent stories of preventable disease outbreaks caught my attention:

Polio outbreak in Tajikistan: http://www.physor...267.html

Whooping cough now an epidemic in California: http://blogs.disc...ifornia/

From the California cases:

"Infants aren’t fully protected against pertussis until they have completed the first schedule of vaccinations, when they reach 6 months. Before then, they are vulnerable to the disease. The most likely reservoir for the bacterium? Unvaccinated people, including other children. If too many people go unvaccinated, the disease can find a host and survive long enough to infect others. If enough people are vaccinated, that chance drops. This effect is called herd immunity, and it’s the only thing that can keep this highly contagious and potentially fatal disease away from infants."

5 deaths of infants under three months of age this year already. Enough!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.