Tag: correlation

Should I Blame the Vaccine If I’m Sick and I Just Got Vaccinated?

We all know the saying, correlation equals causation, right?

So if you get an MMR vaccine and get the measles a week later, it has to be the vaccine, right?

Should I Blame the Vaccine If I’m Sick and I Just Got Vaccinated?

Actually, no.

“Correlation does not imply causation.”

Although it would be very easy to blame the vaccine, if you keep in mind that the saying is actually “correlation does not imply causation,” maybe you will do a little investigating and see if something else is to blame.

Some things to consider and ask yourself:

  1. Do I really have measles? Remember that it is not uncommon to develop a fever and a rash about 7 to 12 days after getting an MMR vaccine. This is a very common, mild vaccine reaction. It doesn’t mean that you have measles or even a mild case of the measles.
  2. Was I recently exposed to someone with measles? If you were vaccinated because you were exposed to measles during an outbreak, then there is a good chance that the vaccine hasn’t had a chance to work yet and you actually developed measles from being exposed to the wild virus.
  3. Do I have the wild type or a vaccine strain of measles? Testing can be done to tell which strain of measles you have and to see if it is a wild type or vaccine strain.

Are there any examples of folks having wild type disease if they get sick shortly after being vaccinated?

Not surprisingly, there are a lot of these types of examples.

“Vaccine strains are poorly or not transmissible and prompt differentiation between wild-type and vaccine strains allows for optimal management and public health action.”

Pabbaraju et al on Simultaneous Detection and Differentiation between Wild-Type and Vaccine Measles Viruses by a Multiplex Real-Time Reverse Transcription-PCR Assay

What about examples of folks getting sick with vaccine strain measles and other diseases? Not so many.

The clinical diagnosis could just as easily have been wild type measles and not a vaccine strain, as there was a lot of measles in the the UK in 1988.
The clinical diagnosis could just as easily have been wild type measles, as there was a lot of measles in the the UK in 1988.

Most of the published examples are case reports without evidence of a vaccine strain.

What about the kid in Canada that got measles after her MMR vaccine?

“We describe a case of vaccine-associated measles in a two-year-old patient from British Columbia, Canada, in October 2013, who received her first dose of measles-containing vaccine 37 days prior to onset of prodromal symptoms.”

Murti et al on Case of vaccine-associated measles five weeks post-immunisation, British Columbia, Canada, October 2013.

She had symptoms of measles and a vaccine strain and was reported as “the first case of MMR vaccine-associated measles.” Well, at least the first case that occurred so long after getting vaccinated. Still, they note that “clinically significant vaccine-associated illness is rare.”

What about all of the people in California and Michigan who supposedly had vaccine-strain measles?

This is not vaccine strain measles! It is people with a rash or fever after being vaccinated. They don't have measles though.
This is not vaccine strain measles! It is people with a rash or fever after being vaccinated. They don’t have measles though.

Anti-vaccine folks made that up!

When It’s a Wild-Type Virus

What’s the most obvious evidence against the idea that vaccines and shedding are responsible for causing outbreaks?

For one thing, despite the recent uptick, cases of vaccine-preventable diseases are way down from the pre-vaccine era. That’s not what you would expect if vaccine-induced disease was common or if contacts of those who were recently vaccinated could easily get sick from shedding.

And we have evidence against vaccine induced disease.

When kids get chicken pox shortly after being vaccinated, they often have a wild strain. They don’t have breakthrough chicken pox.

“All of 57 vaccinees with breakthrough varicella, clinically diagnosed on the basis of a generalized maculopapular or vesicular rash, in which there was amplifiable DNA [corrected], had wild-type VZV infection based on analysis of viral DNA. “

LaRussa on Viral strain identification in varicella vaccinees with disseminated rashes.

Same thing with measles.

Want to avoid these situations in which you could get a wild strain of a vaccine-preventable disease?

Don’t skip or delay your child’s vaccines!

More On Wild-Type and Vaccine Measles Viruses

Side Effects and Adverse Events Following Immunizations

Vaccines are safe, but they do have some side effects, mostly mild, and they rarely cause some serious and severe adverse reactions.

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

To help keep our vaccines safe, it is important that all “clinically important adverse events that occur after vaccination of adults and children” be reported to VAERS, not just the ones that are known to be side effects.

Wait.

Isn’t an adverse event the same as a side effect?

Adverse Events Following Immunizations

To better understand that, let’s first look at how we define an adverse event following immunization (AEFI):

“An Adverse event following immunization (AEFI) is any untoward medical occurrence which follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine. The adverse event may be any unfavourable or unintended sign, abnormal laboratory finding, symptom or disease.”

Classification of AEFIs

So it should be clear that not all adverse events are actually caused by vaccines.

Many are coincidental events that simply occur after a vaccine is given.

What’s the Difference Between Side Effects and Adverse Events Following Immunizations?

Others are true vaccine reactions though, including fever, pain, fainting, and allergic reactions, etc.

“A side effect is any health problem shown by studies to be caused by a vaccine. Like any medication, vaccines can cause side effects. Usually vaccine side effects are minor (for example, a sore arm where a shot was given or a low-grade fever after a vaccine) and go away on their own within a few days.”

Understanding Side Effects and Adverse Events

These are the reactions that we call side effects or adverse reactions of the vaccine.

Still, just because a sign or symptom can be a side effect of a vaccine doesn’t mean that it always will be.

“A vaccine reaction is an individual’s response to the inherent properties of the vaccine, even when the vaccine has been prepared, handled and administered correctly.”

Vaccine reactions – WHO Vaccine Safety Basics

Here are some other definitions:

  • adverse event – Medical occurrence temporally associated with the use of a medicinal product, but not necessarily causally related.
  • adverse reaction/side effect – A response to a drug which is noxious and unintended, and which occurs at doses normally used in man for the prophylaxis, diagnosis, or therapy of disease, or for the modifications of physiological function.
  • unexpected adverse reaction – Not consistent with applicable product information or characteristics of drug.
  • severe adverse event or reaction – are rarely life-threatening and usually do not result in long-term problems
  • serious adverse event or reaction – Any untoward medical occurrence that at any dose is life-threatening, results in death, requires inpatient hospitalization or prolongation of existing hospitalization, or results in persistent of significant disability or incapacity

Does understanding those definitions make it easier to see why you should be skeptical when folks try to scare you with VAERS reports and data from package inserts?

“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

They both can include reports about adverse events, not just side effects. So they both include events that can very well be coincidental, and not caused by a vaccine.

So when doing your research about vaccines, focus on real side effects, or things that are known to be caused by vaccines. You will find that most vaccine side effects are mild and that more serious or severe side effects are very rare.

More on Side Effects and Adverse Events

Do Vaccines Cause Psoriasis?

Even with all of the so-called vaccine-induced diseases that anti-vaccine folks come up with, few people likely think that vaccines cause psoriasis.

Bob Sears is being investigated by the California Medical Board for giving these medical exemptions because he thinks vaccines cause psoriasis.
Bob Sears is being investigated by the California Medical Board for giving these medical exemptions. Were they legitimate?

Some do though…

Do Vaccines Cause Psoriasis?

Bob Sears thinks that these kids shouldn’t be vaccinated because “vaccines can trigger psoriasis or make existing psoriasis worse.”

Dr. Bob did his research and thinks that vaccines are a risk to cause lifelong psoriasis.
Dr. Bob did his research and thinks that vaccines are a risk to cause lifelong psoriasis.

He even provided a list of studies that he thinks support his case.

“Nevertheless, the likely very low incidence of psoriasis following vaccination emphasizes the safe profile and the relevance of vaccination strategies in psoriasis patients, especially in candidates for immunosuppressive treatments.”

Sbidian et al on National survey of psoriasis flares after 2009 monovalent H1N1/seasonal vaccines.

Do they?

“The risk of psoriasis was also increased in subjects who reported a history of a recent infectious episode. The analysis by individual diagnosis pointed to acute pharyngitis as the disease with the strongest association and the only one providing statistically significant results…”

Naldi et al on Family history of psoriasis, stressful life events, and recent infectious disease are risk factors for a first episode of acute guttate psoriasis: results of a case-control study

Let’s see, although I’m not sure he actually read more than the abstracts or understands that guttate psoriasis isn’t the same as plaque psoriasis

  1. Possible Triggering Effect of Influenza Vaccination on Psoriasis – a small group of patients (36) either had an exacerbation of their psoriasis, or new onset of psoriasis (7), within a couple of weeks to months after getting a flu shot.
  2. Psoriasis triggered by tetanus-diphtheria vaccination – a case report of a 50-year-old with chronic psoriasis for 6 years who developed an exacerbation a week after getting a tetanus booster.
  3. Psoriatic skin lesions induced by BCG vaccination – a case report of a 6-month-old who developed a BCG-induced tuberculid-like eruption accompanied by psoriatic skin changes one month after vaccination. They went away without treatment within 3 months.
  4. Guttate psoriasis-like lesions following BCG vaccination – a case report of a 7-year-old who developed guttate psoriasis-like lesions one week after his BCG vaccination. He was treated with steroid creams and the rash went away within three weeks.
  5. New Onset Guttate Psoriasis Following Pandemic H1N1 Influenza Vaccination – a case report of a 26-year-old who developed guttate psoriasis after getting a flu shot. Her rash went away within three weeks.
  6. National survey of psoriasis flares after 2009 monovalent H1N1/seasonal vaccines – a small group of patients (10) who either developed new onset psoriasis or had an exacerbation after getting a flu shot.
  7. Psoriasis vaccinalis; report of two cases, one following B.C.G. vaccination and one following vaccination against influenza – from 1955, two case reports of psoriasis after BCG vaccine and the flu shot.
  8. Family history of psoriasis, stressful life events, and recent infectious disease are risk factors for a first episode of acute guttate psoriasis: results of a case-control study – a case control study that “confirmed that recent pharyngeal infection is a risk factor for guttate psoriasis. It also documented the strong association between guttate psoriasis and a family history of psoriasis. Finally, the study added evidence to the belief that stressful life events may represent risk factors for the onset of psoriasis.” The study doesn’t mention vaccines, but does remind us that “it has been estimated that only one third of cases of guttate psoriasis progress to chronic plaque psoriasis, whereas a history of guttate psoriasis is not frequent in patients with psoriasis.”
  9. Genetic background of psoriasisdoesn’t mention vaccines.

So, none of Bob’s studies were in children, they are mostly about flu shots and the BCG vaccine (which isn’t used in the United States), they are mostly case reports (low on the hierarchy of evidence), and a few don’t mention vaccines…

And most aren’t about chronic psoriasis!

Explaining the Correlation of Psoriasis After Vaccines

Is there anything that might explain the case reports that do show an association between vaccines and psoriasis flares?

“Psoriasis can appear in areas of the skin that have been injured or traumatized. This is called the Koebner [KEB-ner] phenomenon. Vaccinations, sunburns and scratches can all trigger a Koebner response. The Koebner phenomenon can be treated if it is caught early enough.”

National Psoriasis Association on Causes and Triggers

Experts also talk about Th1- and Th17-predominant immunologic responses of flu shots and the BCG vaccine’s Th17 activity. It is known that Th17 cells play a role in psoriasis.

Are there any other studies about vaccines and psoriasis that Dr. Bob left out?

  1. Yellow fever vaccine used in a psoriatic arthritis patient treated with methotrexate: a case report – “A case of yellow fever vaccine used in a 27-year-old Slovenian male with psoriatic arthritis during treatment with methotrexate is described. We demonstrate a positive case, since there were no adverse effects in concurrent administration of yellow fever vaccine and methotrexate.”
  2. Live attenuated varicella vaccine: A new effective adjuvant weapon in the battlefield against severe resistant psoriasis, a pilot randomized controlled trial – a study of 35 patients which found that the “use of chickenpox vaccine with low-dose cyclosporine seems to have value for the treatment of resistant psoriasis.”
  3. [Psoriasis is no obstacle to smallpox vaccination] – (I haven’t found the full article yet, but the title is intriguing, since eczema is a contraindication to getting the smallpox vaccine…)
  4. Factors associated with 2009 monovalent H1N1 vaccine coverage: a cross sectional study of 1,308 patients with psoriasis in France – mentions that more than twice as many people with psoriasis in France got a flu shot than the general population.
  5. Immune response to pneumococcus and tetanus toxoid in patients with moderate-to-severe psoriasis following long-term ustekinumab use – vaccines work when you have psoriasis!
  6. From the Medical Board of the National Psoriasis Foundation: monitoring and vaccinations in patients treated with biologics for psoriasis – addresses vaccination practices for folks with psoriasis.
  7. Challenges in the treatment of psoriasis with biologics: vaccination, history of malignancy, human immunodeficiency virus (HIV) infection, and pediatric psoriasis – actually talks about how UNDERVACCINATION is a challenge in treating kids with psoriasis, as you might have to interrupt therapy to get them caught up!
  8. Vaccinations in patients with immune-mediated inflammatory diseases – is very clear that the “Clinical evidence indicates that immunization of IMID patients does not increase clinical or laboratory parameters of disease activity. Live vaccines are contraindicated in immunocompromized individuals, but non-live vaccines can safely be given.”

The bottom line is that experts that treat people with psoriasis recommend that they be fully vaccinated.

“Psoriasis is a treatable, chronic dermatosis. The very low absolute risk of new-onset or relapsed psoriasis following influenza vaccination should not change its universal recommendation, particularly for patients with psoriasis on immunosuppressive therapy. We present this case to highlight clinical manifestations of this rare association.”

Shi et al on Widespread psoriasis flare following influenza vaccination

There is even talk of development of a vaccine to treat psoriasis!

It should be clear that neither psoriasis nor a family history of psoriasis should be a reason to get a medical exemption for vaccines.

More on Vaccines and Psoriasis

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