Tag: coincidence

More About Measles Deaths in the United States

Anti-vaccine folks like to talk about death and measles, as long as they can talk about vaccine deaths, something they seem to think happens commonly.

“Over the past ten years in the U.S., there has been one reported death from the measles, and it is unclear based on the medical history of the patient whether and how measles played a role in their death. During the same time period (based on Vaccine Adverse Event Reporting System (VAERS) reports), there have been 105 reported deaths associated with the MMR or MMRV vaccinations.”

Measles Madness: Dr. Brian Hooker’s Statement to WA Legislators

There are two big problems with this statement, that is so often repeated that it is clearly a PRATT – a point refuted a thousand times.

The reports in VAERS about deaths after MMR are not proof of a cause-and-effect relationship.

“Reports of all possible associations between vaccines and adverse events (possible side effects) are filed in VAERS. Therefore, VAERS collects data on any adverse event following vaccination, be it coincidental or truly caused by a vaccine. The report of an adverse event to VAERS is not documentation that a vaccine caused the event.”

Guide to Interpreting VAERS Data

In fact, studies have shown that most of the reports of deaths submitted to VAERS are coincidental and not causally associated with a vaccine.

But what about deaths following a natural measles infection?

There are plenty of those that anti-vaccine folks love to ignore.

Wide-ranging Online Data for Epidemiologic Research = WONDER
Wide-ranging Online Data for Epidemiologic Research = WONDER

Where are they?

There were actually 5 SSPE deaths and 2 measles deaths in 1999, but I started the list from 2000, as that was when the endemic spread of measles was eliminated in the United States.
There were actually 5 SSPE deaths and 2 measles deaths in 1999, but I started the list from 2000, as that was when the endemic spread of measles was eliminated in the United States.

These deaths are all in the CDC Wonder database.

Before the death of the woman in Washington in 2015, the CDC caused a lot of confusion by stating that “the last verifiable death in the United States from acute measles infection occurred in 2003 when there were 2 reported deaths.”

Does that mean that the measles deaths in 2005, 2009, 2010, and 2012 didn’t happen?

Of course not!

The information in the CDC Wonder database comes from death certificates that are sent in from all over the United States to the National Vital Statistics System. The system isn’t like VAERS though, where just anyone can send in a report. Still, they are unverified, which is why the CDC doesn’t mention them all.

Still, if anti-vaccine folks are going to push VAERS reports that we know are likely coincidental, then they shouldn’t ignore these measles deaths.

More About Measles Deaths in the United States

Why Do Some People Think That Vaccines Cause AFM?

So we know that vaccines don’t cause acute flaccid myelitis.

Consider a five-year-old in Maryland who recently came down with symptoms of AFM.

Was he recently vaccinated?

Nope. It had been some time since his four-year-old vaccines. Almost a year. And he had not gotten a flu vaccine yet.

What he did have were worsening symptoms about two weeks after he had seemed to get over a cold, something he has in common with most other kids with AFM.

“To try to pin a tragic yet uncommon neurological condition caused by enteroviruses on vaccines is dangerous and puts more kids at risk.”

Scott Krugman, MD

As with this case, the CDC reports no correlation with vaccines in the cases that they have investigated.

And remember, some of these kids have been unvaccinated!

That makes you wonder why some folks actually think that vaccines are associated with AFM, doesn’t it?

Why Do Some People Think That Vaccines Cause AFM?

That’s right, as you are likely suspecting, the usual suspects are pushing anti-vaccine propaganda and promoting the idea to scare parents away from vaccinating and protecting their kids.

“…there are many other reasons to suspect vaccine-related mechanisms of causation for AFM in the U.S., a primary one being that the scientific literature has documented paralysis as an adverse reaction to vaccination for decades!”

The Non-Polio Illness That “Looks Just Like Polio” by Lyn Redwood, RN, MSN, President, Children’s Health Defense

If any of these kids had recently gotten the oral polio vaccine, then sure, an adverse reaction to the vaccination would be at the top of the list of possible causes. After all, we know that VAPP can occur after OPV, but that vaccine hasn’t been used in the United States since 2000, when we switched to IPV.

Why do these folks think that they have it all figured out?

Vaccines are not causing AFM because of needle puncture wounds or tonsillectomies.
Vaccines are not causing AFM because of needle puncture wounds or tonsillectomies.

The AFM outbreaks happen at the beginning of the school year, when kids are all getting their shots, right?

Nope. They happen during the summer and early fall, peaking in August. And despite what some folks think, most parents don’t wait until the end of summer, just before school starts, to vaccinate their kids. Plus, most kids don’t even need vaccines before the start of the school year. Kids typically only get vaccines before starting kindergarten and middle school.

But the outbreaks do coincide with the when kids get their flu shots, right?

How many kids get flu shots in June and July?

If it was flu shots, the peak would be in October and November, when most kids get their flu shots and we would continue to see cases through December and January.

Many anti-vaccine websites and Facebook groups are pushing the idea that vaccines cause AFM.
Many anti-vaccine websites and Facebook groups are pushing the idea that vaccines cause AFM.

Of course, there is absolutely no evidence that flu vaccines, or any other vaccines, cause AFM.

What about the journal article that Brandy Vaughan posts as evidence?

“By reviewing vaccine-associated inflammatory diseases of the central nervous system, this study describes the current knowledge on whether the safety signal was coincidental, as in the case of multiple sclerosis with several vaccines, or truly reflected a causal link, as in narcolepsy with cataplexy following pandemic H1N1 influenza virus vaccination.”

Vaccine-associated inflammatory diseases of the central nervous system: from signals to causation

Even if you just read the abstract, as many folks do, you get a good idea where they are going with the article. It talks about how the claims of an association between multiple sclerosis and vaccines were proven to be purely coincidental.

Remember, correlation does not imply causation.

With AFM, you don’t even have much correlation to imply causation though!

Most cases occur just before we start giving flu vaccines and they don’t occur every year or in every state.

But doesn’t the article mention myelitis?

“Most of the published associations are based on individual case reports or small series of patients.”

Vaccine-associated inflammatory diseases of the central nervous system: from signals to causation

It does mention myelitis, just like it mentions MS – where an association has been shown to be purely coincidental.

Remember, case reports are not good evidence.

“…there are many other reasons to suspect vaccine-related mechanisms of causation for AFM in the U.S., a primary one being that the scientific literature has documented paralysis as an adverse reaction to vaccination for decades!”

The Non-Polio Illness That “Looks Just Like Polio” by Lyn Redwood, RN, MSN, President, Children’s Health Defense

But isn’t acute flaccid myelitis listed as a possible side affect in the package inserts for our vaccines?

Uh, TRANSVERSE myelitis and ACUTE DISSEMINATED ENCEPHALOmyelitis are not the same as acute flaccid myeltitis.
Uh, TRANSVERSE myelitis and ACUTE DISSEMINATED ENCEPHALOmyelitis are not the same as acute flaccid myelitis.

While it should be clear that AFM isn’t the same as ADEM and TM, it is very important to understand that even when those other conditions are listed in a package insert, it is in the section that is marked “without regard to causality.”

This isn’t evidence that vaccines cause AFM!

But didn’t the BMJ publish a study about Vaccines and the U.S. Mystery of Acute Flaccid Myelitis?

BMJ seems to allow anyone to publish responses to their articles online...
BMJ seems to allow anyone to publish responses to their articles online…

Nope. What they did is let someone publish what is essentially an online letter to the editor. And anti-vaccine folks are spreading it around like it is an actual BMJ study…

Surprised?

You shouldn’t be.

This is how anti-vaccine propaganda works.

Why are vaccine injury lawyers talking about AFM?
Why are vaccine injury lawyers talking about AFM?

It’s no coincidence that anti-vaccine folks are trying so hard to associate the outbreaks of AFM with vaccines. What better way to scare folks and make them think that vaccines are dangerous?

AFM is all that anti-vaccine folks are talking about these days...
AFM is all that anti-vaccine folks are talking about these days…

How are ‘we’ working on a vaccine for AFM if we don’t even know what causes AFM???

But that’s how many anti-vaccine folks think. Everything is a vaccine injury. Everything is a conspiracy.

Don’t believe them. Vaccines are safe and necessary.

More on Anti-Vaccine Propaganda About AFM

 

VigiAccess Numbers in Context

Most people are familiar with VAERS, the Vaccine Adverse Event Reporting System.

They sometimes forget that it is only the Vaccine Adverse Event Reporting System for the United States.

Other countries have their own vaccine safety systems.

VigiAccess Numbers in Context

One of the biggest is VigiBase, the World Health Organization’s  global database for suspected adverse drug reactions, maintained by the Uppsala Monitoring Centre in Sweden.

“Information on suspected ADR should not be interpreted as meaning that the medicinal product in question, or the active substance(s), generally causes the observed effect or is unsafe to use.”

Not surprisingly, folks misuse VigiBase numbers, just like they misuse VAERS reports.

JB Handley needs help understanding VigiAccess reports.
JB Handley needs help understanding VigiAccess reports.

To look at the VigiBase reports, you can use VigiAccess.

“VigiAccess has a search interface that allows visitors to retrieve summary statistics on suspected adverse reactions to medicines and vaccines.”

Uppsala Monitoring Centre

While VigiBase “is at the heart of UMC’s signal detection and scientific research,” you aren’t going to learn much from VigiAccess.

“Geographically, only continent-level statistics are shown, due to issues relating to patient confidentiality and data protection in individual countries.”

Uppsala Monitoring Centre

The biggest problem?

You don’t know how many vaccines were given to all of those people.

For example, while it might sound like there have been a lot of adverse drug reaction reports for the DTaP vaccine, with 179,447 reports in VigiAccess, since those are worldwide reports since 1968, it is likely among many billions of doses of vaccines being given.

Most importantly though, as with VAERS, “The reports in VigiBase result from suspicions of a relationship between a drug and a reaction. No causal relation has been confirmed.”

So how do you put the numbers from VigiBase and VigiAccess in context?

If you consider that reports and safety signals from VigiBase, VigiMatch, VigiRank, and other tools used by the Uppsala Monitoring Centre continue to find that vaccines are safe, then to put the DTaP numbers in context, they help us know that vaccines are being well monitored for safety.

And since we know that these diseases haven’t disappeared, any further context, if you need it, would be that since vaccines are safe and necessary, then you should get yourself and your family vaccinated and protected.

More on VigiBase and VigiAccess

 

Vaccine Injuries vs Coincidences

Believe it or not, some folks don’t think that coincidences are real.

Not believing in coincidences is a well known trope of the anti-vaccine movement.
Not believing in coincidences is a well known trope of the anti-vaccine movement.

Is it a coincidence that these folks are the ones who are the most likely to believe that vaccines cause a lot of injuries and vaccine induced diseases?

Vaccine Injuries vs Coincidences

Thinking about vaccine side effects and coincidences is not new.

“When I undertook the study with the current vaccine strain on my own two triple-negative children and their three playmates, also triple- negatives, I thought: “I am going to do this very carefully now,” and, like Dr. Gear, I set up certain time schedules. I said: “I am going to start to give the vaccine now.” Every time I said “I am going to start to give it” and did not give it, two to three or four days later they came down with either pharyngitis, vomiting and abdominal pain, or a little fever.

I waited for approximately six weeks for those children to stop having some sort of febrile episode. I finally gave up. It so happened that after they got the vaccine they did not have any such episode.”

Albert Sabin on Recent Studies And Field Tests With A Live Attenuated Poliovirus Vaccine

When Albert Sabin was first researching his oral polio vaccine, he understood the problem. How could he really know if any signs or symptoms that occurred after he gave someone his vaccine were really caused by the vaccine, or just a coincidence?

“However, a report later to be given by Dr. Smorodintsev will deal with approximately 7,500 children who had received the vaccine and were carefully followed, as compared with another group, in similar number, who had not, for various types of illnesses which were occurring during the period.”

Albert Sabin on Recent Studies And Field Tests With A Live Attenuated Poliovirus Vaccine

The solution? They studied kids who had not gotten his vaccine.

But you don’t need an unvaccinated group to uncover coincidences.

You can just look at the background rate of a symptom or condition, and compare the periods before and after you start using a vaccine.

For instance, consider this study from Australia about using the HPV vaccine in boys, in which they made some predictions of what would happen after introducing the HPV vaccine.

Assuming an 80% vaccination rate with three doses per person — which equates to about 480 000 boys vaccinated and a total of 1 440 000 doses administered nationally per year in the first 2 years of the program — about 2.4 episodes of Guillain-Barré syndrome would be expected to occur within 6 weeks of vaccination. In addition, about 3.9 seizures and 6.5 acute allergy presentations would be expected to occur within 1 day of vaccination, including 0.3 episodes of anaphylaxis.

Clothier et al. on Human papillomavirus vaccine in boys: background rates of potential adverse events.

Wait. Are they saying that the HPV vaccine is going to cause Guillain-Barré syndrome, seizures, allergic reactions, and anaplylaxis?

Of course not. When the study was done, the kids hadn’t gotten any vaccines yet!

That was the background rate of those conditions.

They happened before the vaccine was given, and you can expect them to continue to happen after these kids start getting vaccinated – at that same rate.

What if they start happening more often after kids get vaccinated?

Then it makes it less likely to be a coincidence and more likely that the vaccine is actually causing an increase in the background rate. And vaccine safety studies look for that, which is how we know that vaccines don’t cause SIDS, transverse myelitis, multiple sclerosis, and many other conditions.

Most of you will have heard the maxim “correlation does not imply causation.” Just because two variables have a statistical relationship with each other does not mean that one is responsible for the other. For instance, ice cream sales and forest fires are correlated because both occur more often in the summer heat. But there is no causation; you don’t light a patch of the Montana brush on fire when you buy a pint of Haagan-Dazs.

Nate Silver on The Signal and the Noise

Of course, when we are talking about coincidences, we are also talking about correlation and causation.

When correlation doesn’t equal causation, then it’s probably a coincidence. Or it’s at least caused by some other factor.

And coincidences happen all of the time.

Is It a Vaccine Injury or a Coincidence?

That something could be a coincidence is not typically want parents want to hear though, especially if their child has gotten sick.

What does it mean that something happens coincidentally?

“Most sudden cardiac deaths that remain unexplained after necropsy are probably caused by primary cardiac arrhythmias.”

Sudden death in children and adolescents

Often it just means that it is unexplained. And that it is chance alone that it occurred as the same time as something else.

“In the absence of a specific etiology for ASDs, and a tendency among parents of children with a disability to feel a strong sense of guilt, it is not surprising that parents attempt to form their own explanations for the disorder in order to cope with the diagnosis.”

Mercer et al on Parental perspectives on the causes of an autism spectrum disorder in their children

Again, when folks blame vaccines, it is often because they have nothing else to blame.

“In some fraction of the American population, however, the belief in a link remains. One reason is a coincidence of timing: children are routinely vaccinated just as parents begin to observe signs of autism. Most vaccines are administered during the first years of life, which is also a period of rapid developmental changes. Many developmental conditions, including autism, don’t become apparent until a child misses a milestone or loses an early skill, a change that in some cases can’t help but be coincident with a recent vaccination.”

Emily Willingham on The Autism-Vaccine Myth

Think that it is too big of a coincidence that some infants develop spasms shortly after their four month vaccines?

Dr. William James West first described these types of infantile spasms in the 1840s!

And the “Fifth Day Fits,” seizures that began when a newborn was five days old, was described in the 1970s, well before we began giving newborns the hepatitis B vaccine.

But SIDS was only discovered after we began vaccinating kids, right?

“But, with millions upon millions of doses given each year to infants in the first 6 months of life across industrialized countries and with sudden infant death syndrome being the most common cause of infant death among infants 1 month or older, the coincidence of SIDS following DTP vaccination just by chance will be relatively frequent. When the two events occur, with SIDS following vaccination, well-meaning and intelligent people will blame the vaccine. They seek order out of randomly occurring events.”

Jacobson et al. on A taxonomy of reasoning flaws in the anti-vaccine movement

Of course not.

Cases of SIDS have been described throughout recorded history and have been well studied to prove that they are not associated with vaccines.

“Some events after immunisation are clearly caused by the vaccine (for example, a sore arm at the injection site). However, others may happen by coincidence around the time of vaccination. It can therefore be difficult to separate those which are clearly caused by a vaccine and those that were going to happen anyway… Scientific method is then used to determine if these events are a coincidence or a result of the vaccine.

Vaccine side effects and adverse reactions

It is easy to blame a vaccine when something happens and a child was recently vaccinated. That is especially true now that anti-vaccine folks turn every story of a child’s death or disability into a vaccine injury story.

“Autism was known well before MMR vaccine became available.”

Chen et al. on Vaccine adverse events: causal or coincidental?

Blaming vaccines when it is clear that vaccines aren’t the cause doesn’t help anyone though. It scares other parents away from vaccinating and protecting their kids. And it doesn’t help parents who need support caring for a sick child or help coping with the loss of a child.

What to Know About Vaccine Injuries vs Coincidences

While all possible adverse events after getting a vaccine should be reported to VAERS and your pediatrician, remember that just because something happened after getting vaccinated, it doesn’t mean that it was caused by the vaccine.

More on Vaccine Injuries vs Coincidences

Can Vaccines Cause Kawasaki Disease?

Kawasaki disease is rare and there is a good chance that you have never even heard of it, even though the first case was diagnosed in 1961.

Kids with this condition are typically irritable and can develop high fever, swollen glands in their neck, red eyes, red, cracked lips, red, swollen hands and feet, and a rash.

If you have heard of it, there is a good chance it is because anti-vaccine folks are using Kawasaki disease to scare you away from vaccinating and protecting your kids. Lately, talk about Kawasaki disease and the meningococcal B vaccines have been going around.

What Causes Kawasaki Disease?

Kawasaki disease is a type of vasculitis.

Kids who develop Kawasaki disease, who are typically under age 5 years, develop inflammation of their blood vessels, which leads to many of the symptoms and complications we see.

What causes this inflammation?

“Evidence suggests that Kawasaki disease may be linked to a yet-to-be identified infectious agent, such as a virus or bacteria. However, despite intense research, no bacteria, virus, or toxin has been identified as a cause of the disease.”

AAP on Kawasaki disease

We don’t know.

Can Vaccines Cause Kawasaki Disease?

Ask about Kawasaki disease if your child has a fever for five days and other symptoms of Kawasaki disease.
Courtesy of the kdfoundation.org

Because the cause of Kawasaki disease is unknown, that leads some folks to think that it could be vaccines.

Could it?

That vaccine clinical trial data sometimes finds a higher, although not statistically significant risk for Kawasaki disease, gets some of those folks thinking about it even more, except they don’t seem to think about the fact that the risk is never statistically significant.

But aren’t there case reports of kids getting Kawasaki disease after getting a hepatitis A, yellow fever, hepatitis B, or flu vaccine?

Yes, but getting a case report published about one patient who you think got Kawasaki disease soon after getting a vaccine isn’t strong evidence that it wasn’t a coincidence.

“Childhood vaccinations’ studied did not increase the risk of Kawasaki disease; conversely, vaccination was associated with a transient decrease in Kawasaki disease incidence. Verifying and understanding this potential protective effect could yield clues to the underlying etiology of Kawasaki disease.”

Abrams et al. on Childhood vaccines and Kawasaki disease, Vaccine Safety Datalink, 1996-2006.

And not surprisingly, several studies have shown that there isn’t any extra risk for Kawasaki disease after routine vaccines.

One even showed that getting vaccinated could be protective! Another benefit of vaccines and another reason you shouldn’t skip or delay your child’s immunizations.

What to Know About Vaccines and Kawasaki Disease

While anti-vaccine folks often list Kawasaki disease among their vaccine-induced diseases, several studies have shown that vaccines are not associated with Kawasaki disease, except to maybe have a protective effective if you are fully vaccinated.

More on Vaccines and Kawasaki Disease

What Is Vaccine Injury Denial?

Few people deny that vaccine injury is real.

Vaccine injuries, while rare, are certainly real.

That’s why we have table injuries, the Vaccine Court, and the National Vaccine Injury Compensation Program.

What Is Vaccine Injury Denial?

Again though, vaccine injuries are rare.

“Vaccine Injury Denialism is rampant across the mainstream media, where child-abusing vaccine pushers like the New York Times, Washington Post and CNN deliberately contribute to the holocaust of vaccine injuries now devastating humanity’s children. Sadly, the same denialism about the alarming growth in medical injuries caused by vaccines is also endemic across universities, science journals and medical schools, where doctors are indoctrinated into a kind of “Flat Earth” denialism of vaccine injury reality.”

Mike Adams on Vaccine Injury Denialism is the denial of fundamental human dignity

Claims of vaccine injury denial come when we are skeptical or don’t believe that anything and everything is a vaccine injury.

Barbara Loe Fisher's NVIC even claims that Shaken Baby Syndrome can be a vaccine injury.
Barbara Loe Fisher’s NVIC even claims that Shaken Baby Syndrome can be a vaccine injury.

For example, in some circles, if you point out that vaccines do not cause asthma, ADHD, autism, Celiac disease, diabetes, eczema, food allergies, infertility, multiple sclerosis, POTS, SIDS, or transverse myelitis, etc., then claims of vaccine injury denial begin to fly.

That shouldn’t be surprising, as these and other so-called vaccine induced diseases make up the bulk of the vaccine injury stories that scare many parents.

“IMAGINE YOU LIVE IN A COUNTRY in which a minority of people are taken in the middle of the night, and beaten, kicked, poisoned, half-drowned… they are crippled for life, maimed, and they are expected to accept a doctor’s or a judge’s view that “It wasn’t the Gestapo” or “It’s not even an injury”.

Imagine that minority amounted to tens of millions of people.

Now imagine that these victims are lured into traps by their own doctors with promises of medicine that will prevent illness – but in reality the doctors are paid for every patient they manage to convince to show up – and the doctors determine which injuries they caused and which were just “coincidences”.

Now imagine the media is primed to tell the world that no such injuries ever occur. Now your neighbors are denying it, calling you crazy for thinking there is a link…”

James Lyons-Weiler on Should Vaccine Risk/Injury Denial Be Prosecutable Offenses?

But doctors and the media, and your neighbors for that matter, don’t deny that claims of vaccine injury are real because of some grand conspiracy or simply because they want to.

It is because of research and science, understanding the difference between correlation and causation, and more research. And we understand that vaccines are both passively and actively monitored for side effects.

Vaccine injuries, although real, are rare.

The only denialism about vaccines that is important, is among those who deny that vaccines work and that they are safe and necessary.

What to Know About Vaccine Injury Denial

Anti-vaccine folks like to claim that anyone who doesn’t believe that vaccines cause all of their vaccine-induced diseases are part of a conspiracy of vaccine injury denial.

More on Vaccine Injury Denial

Is It a Vaccine Reaction?

Why do anti-vaccine folks think that there are so many vaccine reactions?

It is mostly because they think that anything bad that happens after someone is vaccinated, even if it is weeks or months later, must have been caused by the vaccine.

“Differentiation between coincidence and causality is of utmost importance in this respect. This is not always easy, especially when an event is rare and background rates are not available.”

Heininger on A risk-benefit analysis of vaccination

Of course, this discounts that fact that most people have a basic risk, often called the background rate, for developing most of these very same conditions, and they can just coincide with getting vaccinated.

Put more simply, the “reaction” would have happened whether or not they had been vaccinated.

“…when a number of well-controlled studies were conducted during the 1980s, the investigators found, nearly unanimously, that the number of SIDS deaths temporally associated with DTP vaccination was within the range expected to occur by chance. In other words, the SIDS deaths would have occurred even if no vaccinations had been given.”

WHO on Six Common Misconceptions About Immunization

That doesn’t mean that everything automatically gets blamed on coincidence though.

Is It a Vaccine Reaction?

Vaccine adverse events can be reported to VAERS online or using a downloadable form.
Vaccine reactions can be reported to VAERS online or using a downloadable form.

When trying to determine if a child has had a vaccine reaction, experts typically go through a series of questions, looking at the evidence for and against :

  • How soon after the vaccine was given did the reaction occur? Was it minutes, hours, days, weeks, months, or years later?
  • Is there any evidence that something else could have caused the reaction?
  • Is there a known causal relation between the reaction and the vaccine?
  • Is the reaction a table injury?
  • Is there evidence that the vaccine does not have a causal association with the reaction?
  • Do any lab tests support the idea that it was a vaccine reaction?

Why is it important to consider these and other questions?

Because most of us are very good at jumping to conclusions, are quick to place blame, and like to know the reasons for why things happen.

We don’t like to think that things are just caused by coincidence.

Post hoc ergo propter hoc (after this, therefore, because of this).

We are especially good at linking events and often automatically assume that one thing caused another simply because it occurred afterwards.

It is incident to physicians, I am afraid, beyond all other men, to mistake subsequence for consequence.

Dr Samuel Johnson

But we also know that correlation does not imply causation. And because of the great benefits of vaccines, it is important to find strong evidence for a correlation before we blame vaccines for a reaction.

Too often though, the opposite happens. Despite strong evidence against a correlation, parents and some pediatricians still blame vaccines for many things, from SIDS and encephalitis to autism.

Background Rates vs Vaccine Reactions

Although anti-vaccine folks are always calling for vaccinated vs unvaccinated studies to further prove that vaccines are indeed safe, much of that work is already done by looking at the observed rate of possible reactions and comparing them to the background rate of reactions and conditions.

We often know how many people are expected to develop certain conditions, from seizures and type 1 diabetes mellitus to acute transverse myelitis and juvenile and rheumatoid arthritis.

“On the basis of the reviewed data, if a cohort of 10 million individuals was vaccinated in the UK, 21.5 cases of Guillain-Barré syndrome and 5.75 cases of sudden death would be expected to occur within 6 weeks of vaccination as coincident background cases. In female vaccinees in the USA, 86.3 cases of optic neuritis per 10 million population would be expected within 6 weeks of vaccination. 397 per 1 million vaccinated pregnant women would be predicted to have a spontaneous abortion within 1 day of vaccination.”

Black et al on Importance of background rates of disease in assessment of vaccine safety during mass immunisation with pandemic H1N1 influenza vaccines

Intussusception is a good example of this.

This might surprise some folks, but we diagnosed and treated kids with intussusception well before the first rotavirus vaccines were ever introduced. And then, it was only after the risk of intussusception after vaccination exceeded the background rate that experts were able to determine that there was an issue.

Background rates also explain why unvaccinated kids develop autism. It’s not a coincidence.

“Knowledge of the background incidence rates of possible adverse events is a crucial part of assessing possible vaccine safety concerns. It allows for a rapid observed vs expected analysis and helps to distinguish legitimate safety concerns from events that are temporally associated with but not necessarily caused by vaccination.”

Gadroen et al on Baseline incidence of intussusception in early childhood before rotavirus vaccine introduction, the Netherlands, January 2008 to December 2012

Fortunately, studies have never found an increased risk above the background rate for SIDS, non-febrile seizures, and other things that anti-vaccine folks often blame on vaccines. So when these things happen on the same day or one or two days after getting vaccinated, it almost certainly truly is a coincidence. It would have happened even if your child had not been vaccinated, just like we see these things happen in the days before a child was due to get their vaccines.

For example, using background incidence rates in Danish children, one study found that if you vaccinated a million children with a new flu vaccine, you could expect that naturally, after seven days, you would see:

  • facial nerve palsy – one case
  • seizures – 36 cases
  • multiple sclerosis – one case
  • type 1 diabetes – three cases
  • juvenile and rheumatoid arthritis – three cases

After six weeks, those numbers of course go up. In addition to 4 kids developing MS, 20 develop diabetes, 19 develop arthritis, and 218 have seizures, and there would have been at least two deaths of unknown cause.

Would you blame the flu shot for these things?

What flu shot?

This was a “hypothetical vaccine cohort” that used 30 years of data from the Danish healthcare system to figure out background rates of each condition.

“In addition, the expected number of deaths in Japan following an estimated 15 million doses of H1N1 vaccine administered would be >8000 deaths during the 20 days following vaccination, based on the crude mortality rate.”

McCarthy et al on Mortality Rates and Cause-of-Death Patterns in a Vaccinated Population

Looking at background rates is especially helpful when folks report about vaccine deaths.

Using the Japan example that McCarthy studied, if they had looked at background rates, then all of a sudden, the 107 deaths they found after 15 million doses of H1N1 vaccine were given in 2009 would not have been so alarming. Background rates would have predicted a much, much higher number of deaths to naturally occur in that time period simply based on crude mortality rates.

Again, none of this means that possible vaccine reactions are dismissed as being coincidences. They just aren’t immediately assumed to have been caused by vaccines, because vaccines are necessary and a lot of research has already gone into demonstrating that vaccines are safe and vaccines continue to go through routine safety monitoring to make sure they stay safe.

What to Know About Evaluating Vaccine Reactions

Vaccines are safe and many of the things that folks think are vaccine reactions can be explained by looking at the background rates for these conditions and understanding that they would have happened anyway.

More on Evaluating Vaccine Reactions