Tag: correlation

Mistaking Subsequence for Consequence

Most parents understand that vaccines are safe, with few risks, and necessary, but some are still scared to get their kids vaccinated and protected.

Some even get anxious at the idea of going to their next visit to their pediatrician, because it might mean their baby is going to get shots.

Why?

They have likely heard some of those vaccine injury stories and got to thinking – how could all of those parents be wrong?

Mistaking Subsequence for Consequence

It’s easy to make a hasty judgement about something.

We jump to conclusions and try to link things together when they occur at about the same time as each other.

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

That’s because we often mistake subsequence (the state of following something) for consequence (a result of an action).

For example, developing multiple sclerosis (the consequence) six weeks after (subsequent) getting a vaccine, doesn’t mean that the vaccine caused you to develop multiple sclerosis.

Although the source of the quote on subsequence and consequence is Dr. Samuel Johnson, an 18th century writer, it got new life when Justice Jeremy Stuart-Smith used it in a DTP vaccine trial verdict.

“Where given effects, such as serious neurological disease or permanent brain damage, occur with or without pertussis vaccination, it is only possible to assess whether the vaccine is a cause, or more precisely a risk factor, when the background incidence of the disease is taken into account. The question therefore is, does the effect occur more often after pertussis vaccination than could be expected by chance?”

Sir Jeremy Stuart-Smith

What about chance and coincidences?

Instead of thinking that things could simply be the result of chance or a coincidence, we typically want more of an explanation when something happens, and sometimes, we simply want someone or something to blame.

“Establishing or disproving cause and effect, particularly for events of major consequence, proved difficult. Although the original allegations of causation were largely anecdotal and based on the fallacious assumption that subsequences and consequences were synonymous, they raised great concern and stimulated the search for an improved vaccine.”

Vaccines (Seventh Edition)

That leads us to fallacious thinking – post hoc ergo propter hoc (after this, therefore, because of this).

It shouldn’t though.

“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

Remember, “correlation does not imply causation.”

Because polio outbreaks often came in summer months, some folks thought the virus must be spread at swimming pools, so they were often closed. It didn't help... Correlation did not equal causation.
Because polio outbreaks often came in summer months, some folks thought the virus must be spread at swimming pools, so they were often closed. It didn’t help… Correlation did not equal causation.

That maxim becomes easier to understand when you see all of the things that correlate together, like ice cream sales and forest fires, but once you think about them, there is no way that one could cause the other.

  • the consumption of high fructose corn syrup and deaths caused by lightning
  • the divorce rate in Maine and the per capita consumption of margarine
  • autism rates and organic food sales
  • autism rates and Jenny McCarthy‘s popularity?!?

Correlation does not imply causation.

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

Dr Samuel Johnson

Fortunately, it is not as “incident to” (likely to happen to) physicians these days to “mistake subsequence for consequence.”

There are certainly some vaccine friendly pediatricians who pander to the fears of parents and push so-called alternative, non-standard, parent-selected, delayed protection vaccine schedules, who seem to believe in anecdotal evidence above all else, but most doctors understand that vaccines are safe and necessary.

They also know that because correlation can sometimes equal causation, we don’t ignore possible vaccine injuries. And that’s why we have strong vaccine safety systems that can detect and warn us of true vaccine risks.

More on Mistaking Subsequence for Consequence

If It’s Vaccines, Then Why Are There Autistic Kids Who Are Unvaccinated?

Although we know that vaccines aren’t associated with autism, anti-vaccine folks can’t let go of the idea.

Paul Thomas misses the one thing his data is telling him...
Paul Thomas misses the one thing his data is telling him…

So how do they explain all of the autistic kids who are unvaccinated?

If It’s Vaccines, Then Why Are There Autistic Kids Who Are Unvaccinated?

Of course, anti-vaccine folks have a ready answer – it’s vaccines, but it’s not just vaccines.

I guess that’s how they explain the fact that there are so many autistic adults too! Well, actually no. Most anti-vaccine folks are surprised when you point out that there are so many autistic adults, as it doesn’t fit in with their idea that autism is new and caused by kids getting more vaccines than they used to.

Well, I guess mostly caused by giving so many more vaccines than we used to – there are also the autistic kids who were never vaccinated.

How do they explain those kids having autism?

Like their competing theories about how vaccines are associated with autism (it’s the MMR vaccine, no it’s thimerosal, no it’s glyphosate contaminating vaccines, etc.), they have a lot of ideas about how everything else causes autism. From fluoride and chlorine to acetaminophen and aluminum-lined containers, plus mercury, arsenic, aspartame, MSG, and the vaccines your child’s great-grandmother received – they think that just about anything and everything can cause autism. Or at least anything that they think they can sell you a treatment for, such as their supplements, special diet plans, or other “cures.”

Makes you wonder why they still focus on vaccines…

But they do, even as more studies have shown that vaccines are not associated with autism. And since vaccines don’t cause autism, it shouldn’t be surprising that there are unvaccinated children with autism. The only reason there aren’t more is that most parents vaccinate their children, so, of course, most autistic children are going to be vaccinated.

Another reason is that some parents stop vaccinating their kids once they have an autistic child. But since vaccines aren’t associated with autism, which is highly genetic and inheritable, younger unvaccinated siblings born after older siblings were diagnosed often still develop autism.

Now if vaccines didn’t cause autism in these unvaccinated kids, why would anyone still think that they caused autism in their older siblings?

“I must admit that it was through conversations with a coworker that I began to suspect something might be wrong with my youngest son. It concerned me so much that I started looking for information online. I read some of the stories and they sounded similar to what I was experiencing with my son – with the symptoms, the regression and the age at which it all started to become apparent.”

Lara’s Story: Growing Up Anti-Vaccine

Unlike some other stories you might read online, Lara’s story is about her unvaccinated autistic child.

She isn’t alone. You only have to look at personal stories and posts in parenting forums to see that there are many cases of autism among unvaccinated and partially vaccinated children:

  • “It is highly likely my 4-year-old son is autistic. And he is completely 100 percent vaccine-free. And I am just at a total loss.”
  • “I have unvaxxed kids on the spectrum, and my friend does as well.”
  • “A good friend’s son is autistic. He is totally non-vaxxed.”
  • “I seriously delayed vaccinating my son, so had very few vaxxes at the time he was diagnosed”
  • “We have autism in our unvaxxed children”
  • “I know two little boys who are both autistic, completely non-vaxxed”
  • “I have two unvaccinated children who are on the autism spectrum and have never vaccinated any of my children.”
  • “I am not sure what caused my son’s autism, but autistic he is. He is completely unvaxxed as we stopped vaxxing 10 years ago.”
  • “I have a 10 year old daughter with autism spectrum disorder… My daughter has never had a vaccine, a decision I made shortly after she was born, after much research.”

Unfortunately, while realizing that unvaccinated children can develop autism does help some parents move away from anti-vaccine myths and conspiracy theories, others get pushed deeper into the idea that it is just about toxins. It is not uncommon for some of these parents to blame vaccines they got while pregnant or even before they became pregnant, Rhogam shots, or mercury fillings in their teeth, etc.

Fortunately, most don’t though.

Take Juniper Russo, for example.

She “was afraid of autism, of chemicals, of pharmaceutical companies, of pills, of needles” when she had her baby. She just knew that vaccines caused autism when she first visited her pediatrician after her baby was born and knew all of the anti-vaccine talking points. She also later began to realize that her completely unvaccinated daughter had significant developmental delays. Instead of continuing to believe that vaccines cause autism, Ms. Russo understood that she “could no longer deny three things: she was developmentally different, she needed to be vaccinated, and vaccines had nothing to do with her differences.”

And she understands that her autistic child isn’t damaged, as hard as folks in the anti-vaccine movement still try to push the idea that she is.

More on Autistic Kids Who Are Unvaccinated

What Are the Side Effects of the Flu Vaccine?

Like other vaccines, flu vaccines can have side effects.

Fortunately, most of those side effects are mild.

What Are the Side Effects of the Flu Vaccine?

Not surprisingly, a lot of things that get blamed as being caused by flu vaccines are not actually side effects.

Did you actually get the flu in the days or weeks after your flu vaccine?

That’s not a side effect of your flu vaccine. Neither the inactivated flu shot, nor the attenuated FluMist can actually cause a flu infection.

Did you get a little sore at the site where you got your flu shot?

That’s a common side effect to getting a flu shot.

So is having some redness and swelling at the site, all of which begin soon after getting the shot and go away in a few days. You can also get a headache, fever, nausea, and muscle aches or signs and symptoms of an allergic reaction.

Do you have a runny nose or a cough? Side effects of the nasal spray flu vaccine can include a few days of runny nose, wheezing, headache, vomiting, muscle aches, fever, sore throat and cough.

Again, a bad cough and cold after a flu shot isn’t a side effect of the vaccine though.

Remember, correlation does not imply causation.

If you found out you were pregnant shortly after getting a flu shot, you wouldn’t think they were associated, would you?

What about narcolepsy?

“An increased risk of narcolepsy was found following vaccination with Pandemrix, a monovalent 2009 H1N1 influenza vaccine that was used in several European countries during the H1N1 influenza pandemic.”

Narcolepsy Following Pandemrix Influenza Vaccination in Europe

Although the focus has been on the Pandemrix flu vaccine as a trigger for narcolepsy in some countries (the vaccine wasn’t used in the United States), interestingly, several countries that weren’t using the vaccine also saw a spike in narcolepsy cases as the 2009 H1N1 pandemic hit.

Doctors and pharmacies rarely give away flu shots for free. They might not charge a copay sometimes because they are getting paid by your insurance company!
Doctors and pharmacies rarely give away flu shots for free. They might not charge a copay sometimes because they are getting paid by your insurance company!

What about all of the reports of severe reactions and deaths after getting a flu shot that you might hear about? In addition to vaccine injury stories, those reports are to VAERS and typically are not causally related to getting a vaccine.

Why are there so many reports to VAERS and the NVICP about flu vaccines? Since 2006, over 1.6 trillion doses of flu vaccine have been distributed in the United States, which equals about the total of all other vaccines we use.

What Are the Side Effects of This Year’s Flu Shot

Even when folks understand that flu vaccines don’t typically cause serious side effects, the question always comes up whether or not this year’s flu shot is causing more side effects than usual.

That’s actually not unreasonable, even when you consider that the biggest change in most flu vaccines from year to year is the strain of flu viruses they include, and not any of the other ingredients.

In addition to the Pandemrix flu vaccine, in 2010, the use of one brand of flu vaccines in Australia was suspended because they were causing more side effects (fever and febrile seizures) in young children than expected.

“The studies flesh out preliminary findings from CSL in June 2012, which said that the manufacturing process retained more virus component than that of other manufacturers and that the 2010 virus components triggered an excessive immune response in some young kids.”

CSL studies shed light on 2010 flu vaccine seizures

So are there any more side effects this year?

No, there is no evidence of increased side effects from this year’s flu vaccines

More on Flu Vaccine Side Effects

Who Is Mark Green?

Have you heard of Mark Green?

For those of us who grew up watching ER, Mark Green is a household name.

But that’s not the Mark Green I’m talking about…

Who Is Mark Green?

Mark Green is a soon-to-be congressman, recently elected for Tennessee’s Seventh Congressional District.

A Republican, he is also a doctor. Specifically, he became a Army special operations flight surgeon after completing a residency in emergency medicine.

Dr. Hotez was one of the many people who called out Rep Mark Green for his anti-vaccine comments.

Of note, Dr. Green has also made horrible statements about transgender people, saying that they have a disease and that they are an evil that must be crushed.

Although his previous statements led him to withdraw as Trump’s pick for Army Secretary, that didn’t keep folks in Tennessee from sending him to Congress.

And now we have his comments about vaccines and autism…

At a recent town hall meeting in Tennessee, Green said:

“Let me say this about autism,” Green said. “I have committed to people in my community, up in Montgomery County, to stand on the CDC’s desk and get the real data on vaccines. Because there is some concern that the rise in autism is the result of the preservatives that are in our vaccines.

“As a physician, I can make that argument and I can look at it academically and make the argument against the CDC, if they really want to engage me on it,” Green said.

Has he apologized?

Mark Green's statements will hurt autistic families.
Mark Green’s statements will hurt autistic families.

Despite some saying that he has walked back those claims, his main response has been that his comments had been “misconstrued” and that “I’ve vaccinated my kids and let others know they need to vaccinate theirs too.”

Nothing about vaccines and autism.

“There appears to be some evidence that as vaccine numbers increase, rates of autism increase,” Green said. “We need better research, and we need it fast. We also need complete transparency of any data. Vaccines are essential to good population health. But that does not mean we should not look closely at the correlation for any causation.”

Except for when he doubled down on his statements trying to associate vaccines with autism…

So just what did Rep Mark Green mean to say about vaccines and autism?
So just what did Rep Mark Green mean to say about vaccines and autism?

Statements which seemed to cause the Tennessee chapter of the AAP and the Tennessee Department of Health to issue statements of their own.

“Vaccines do not cause autism.”

Tennessee Department of Health Statement on Immunizations

So, is he going to really apologize for his comments, and perhaps learn a bit more about vaccines, vaccine-preventable disease, and autism?

More on Mark Green

How Are Vaccines Related to News About Food Recalls and Food Poisoning?

Do you ever think about vaccines when you think about food recalls?

How about when you think about food poisoning?

Well, maybe you should, after all, we do have vaccines to prevent hepatitis A infections and typhoid fever, both are which can be spread through contaminated food.

How Are Vaccines Related to News About Food Recalls and Food Poisoning?

That’s not exactly what we were talking about though…

Anti-vaccine folks have a new conspiracy theory about food recalls and food poisoning.
Surprise! Anti-vaccine folks have a new conspiracy theory about food recalls and food poisoning. How often do these types of posts correlate with the truth? What do you guys think? Zero?

That’s right, some folks think that the recent food recalls are correlated to vaccines. They are “creating a market” for a new Salmonella enterica serovar Typhimurium vaccine!

“We evaluated the extent of attenuation and immunogenicity of the ΔlppAB and ΔlppAB ΔmsbB mutants of Salmonella enterica serovar Typhimurium when delivered to mice by the oral route.”

Erova et al on Protective Immunity Elicited by Oral Immunization of Mice with Salmonella enterica Serovar Typhimurium Braun Lipoprotein (Lpp) and Acetyltransferase (MsbB) Mutants

At least they are if mice are monitoring our outbreaks and are in the market for a Salmonella enterica serovar Typhimurium vaccine?

How would that work anyway? No, not mice watching the news and ordering vaccines…

Do they actually think that someone is contaminating our food with Salmonella bacteria so that folks will want these vaccines, when they become available?

Food poisoning is horrible!

Whether it is for Listeria, Salmonella, or E. coli, it likely won’t be very hard to get folks vaccinated, if and when they become available.

More on Propaganda About Vaccines and Food Recalls

Diagnosing Vaccine Injuries

Vaccines are often described as one of the greatest public health achievements of the 20th century.

That great benefit also leaves no doubt for most people that getting vaccinated and fully protected far outweighs the very small risks that vaccines might have.

Vaccine Injuries vs Vaccine Side Effects

Vaccines can certainly have side effects.

Fever, pain at the injection site, and redness and swelling where the shot was given are all common, mild problems that can be associated with almost any vaccine.

Some vaccines might also commonly cause fussiness, tiredness or poor appetite, and vomiting within 1 to 3 days of getting the vaccine. Others can cause a rash, headache, or muscle and joint pain for a few days.

Even syncope or fainting can commonly occur within 15 minutes of teens getting a vaccine.

Other vaccine side effects can include persistent crying, nodules at the injection site, limb swelling, and febrile seizures, etc.

These are well known vaccine side effects that are often minor and temporary though.

Is It a Vaccine Injury?

Although the term is typically associated with the anti-vaccine movement, as they tend to think everything is a vaccine injury, it is important to understand that vaccine injuries, although rare, are indeed real.

After all, vaccines are not 100% safe.

In addition to the milder side effects listed above, vaccines can very rarely cause more serious types of adverse events or injuries, including:

  • life threatening allergic reactions
  • brachial neuritis (shoulder pain and then weakness) following a tetanus containing vaccine
  • encephalopathy/encephalitis following a measles, mumps, or rubella, or pertussis containing vaccine
  • chronic arthritis following a rubella containing vaccine
  • thrombocytopenic purpura (ITP) following a measles containing vaccine
  • vaccine-strain measles viral infection in an immunodeficient recipient following a measles containing vaccine
  • intussusception – following a rotavirus vaccine
  • shoulder injury related to vaccine administration – SIRVA

Keep in mind that some of these are just table injuries and are not necessarily proven as being caused by vaccines.

And while vaccines are associated with some serious adverse events, the research is clear that vaccines are not associated with autism, SIDS, and shaken baby syndrome, type 1 diabetes, multiple sclerosis, inflammatory bowel disease, or other so-called vaccine induced diseases.

Or Is It Just a Coincidence?

Dr. Samuel Johnson once said that “It is incident to physicians, I am afraid, beyond all other men, to mistake subsequence for consequence.”

How does this apply to diagnosing vaccine injuries?

Too often we forget that just because one event is subsequent (happens after) another, it does not mean that it was a consequence (was caused by) the first event. It is another way of saying that correlation does not imply causation.

This is also highlighted by missed vaccine stories, events that would surely be blamed on a vaccine injury, except that a vaccine was never actually given for one reason or another.

Most pediatricians have these types of missed vaccine stories, such as:

  • an infant who begins vomiting on the way home from a well appointment and is diagnosed with intussusception (9 month old visit and didn’t get any vaccines)
  • a 4 year old who developed encephalitis just one week after his well check up (no vaccines – DTP had been deferred to his 5 year old visit)
  • a 2 month old who died of SIDS on the night of his scheduled well child visit (no vaccines as they had forgotten to go to the appointment)
  • a 4 month old who had a seizure at his well child visit (no vaccines were given yet as they were still being drawn up)

Or they have kids who begin to have symptoms or are diagnosed with a condition right around the time of a check up when they would routinely get one or more vaccines, but haven’t yet. From diabetes and POTS to transverse myelitis, some parents would have blamed their child’s vaccines if they had actually been vaccinated at that time and subsequently got diagnosed.

My own son started getting migraines when he was 12 years old and about to start 7th grade. Should I blame his headaches on his middle school booster shots? While it would be convenient, it is more likely that genetics are to blame. I started getting migraines at about the same age, and he began getting them just before he got his booster shots.

Diagnosing Vaccine Injuries

How do you know if your child had a true vaccine injury?

Does the reaction fit into the vaccine injury type AND “time period for first symptom or manifestation of onset or of significant aggravation after vaccine administration” as described in the NVICP vaccine injury tables?

That time period, also known as a risk interval, is when “individuals are considered at risk for the development of a certain adverse event following immunization (AEFI) potentially caused by the vaccine.”

For example, did your child develop an anaphylactic reaction within four hours of getting the DTaP vaccine? While a reaction 14 hours after the vaccine would be much less likely to be caused by the vaccine, if it occurred within 4 hours, that could certainly be a vaccine injury.

How about a child who developed thrombocytopenic purpura 90 days after getting his MMR vaccine? That is unlikely to be a vaccine injury, as the MMR vaccine typically causes TTP within 7 to 30 days.

If you think that your child has had a vaccine injury, be sure to talk to your pediatrician. You should also report any vaccine reaction to Vaccine Adverse Event Reporting System (VAERS) and if you truly believe that your child has been injured by a vaccine, you can file a claim with the National Vaccine Injury Compensation Program (VICP).

“You may file a claim if you received a vaccine covered by the VICP and believe that you have been injured by this vaccine.”

What You Need to Know About the National Vaccine Injury Compensation Program (VICP)

How will your pediatrician figure out if it is a vaccine injury? Among the things that they will consider when evaluating a reaction after a vaccine will be the answers to some key questions, including:

  • Is there any evidence that something else caused the reaction? While getting a vaccine could cause an anaphylactic reaction, so could the fact that your child just eat a peanut butter and jelly sandwich.
  • Is there a known causal association between the reaction and the vaccine?
  • Is there strong evidence against a causal association between the reaction and the vaccine?
  • Is there a laboratory test that implicates the vaccine as a cause of the reaction?
  • If the reaction is an infection, did it have a vaccine or wild type origin?

Your pediatrician will also consider other factors when making a decision, including whether other patients were affected (might implicate a contaminated vaccine), and will make sure that the original diagnosis is correct.

Being able to answer all of these questions often puts pediatricians in the unique position of correctly evaluating potential vaccine injuries. There is even a standardized algorithm that can help your pediatrician collect and interpret all of the data they will get when evaluating a possible vaccine injury.

Another algorithm can help evaluate and manage suspected allergic reactions, including immediate or type 1 hypersensitivity reactions and delayed type 3 hypersensitivity reactions. If the reaction is consistent with an allergic reaction and additional doses of the vaccine are still needed, possible next steps in this algorithm include serologic testing for immunity and skin testing with the vaccine or vaccine components.

For extra help, your pediatrician can consult an allergist or immunologist before considering giving your child another vaccine, if necessary. Experts at the Clinical Immunization Safety Assessment (CISA) are also available for consults about suspected vaccine injuries.

Over-Diagnosing Vaccine Injuries

In addition to vaccine side effects and vaccine injuries, it is much more common for children and adults to develop health problems and symptoms after getting a vaccine that have nothing to do with the vaccine. These are events, sometimes tragic, that would have happened even if they had not been vaccinated.

Anytime we see a post about vaccines and SIDS, we know what happened, an anti-vaccine Facebook group is taking advantage of a grieving family.
Anytime we see a post about vaccines and SIDS, we know what happened, an anti-vaccine Facebook group is taking advantage of a grieving family.

Despite the evidence against it, some parents may still think that their child has been injured or damaged by a vaccine, especially if they:

  • believe all of the vaccine injury stories they hear on the Internet
  • misuse vaccine package inserts
  • believe that VAERS reports have all been confirmed to be true
  • think that vaccine injuries can occur months or years after getting a vaccine
  • find a case report in PubMed and think that is convincing evidence of causality, even though it is really nothing more than a glorified anecdote
  • have found their way into a Facebook group where folks think vaccines always injure kids
  • go to a homeopath, chiropractor, or holistic practitioner who told them the child was injured

For example, studies have repeatedly shown that “vaccination does not increase the overall risk of sudden infant death (SIDS),” and that “the risk of SIDS in vaccinated cases and controls is neither increased nor reduced during the early post-vaccination period.”

What should you do if you really think that your child has a vaccine injury?
Just what a parent needs when their baby dies of SIDS, someone to reach out and tell them it was because they had him vaccinated… 

So a VAERS report of SIDS on the night that an infant received his 4 month vaccines, while tragic, would likely not end up being classified as a true vaccine injury.

Neither should a case report or package insert about SIDS influence your thinking about SIDS being associated with a vaccine injury.

Still, it is easy to understand why many like to blame vaccines.

Vaccines are an easy target, especially as most vaccine-preventable diseases are under fairly good control compared to the pre-vaccine era. And in some cases of SIDS, a new case of diabetes, or the sudden death of an older child, etc., it may happen soon after the child was vaccinated, and that correlation is hard to ignore for some folks.

At least it is hard to ignore and easy to be influenced by anti-vaccine folks if you don’t understand the background rate of these diseases – or the fact that a certain number of children will be affected no matter what, and because many kids get vaccinated, it is only a matter of chance that the two get correlated together. 

Vaccines are safe.

They don’t typically cause serious vaccine injuries.

If you do think that your child has a vaccine injury, talk to your pediatrician. Don’t get diagnosed in a Facebook forum…

More on Diagnosing Vaccine Injuries

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