People with Guillain-Barré syndrome develop the rapid onset of muscle weakness and then paralysis. They may also have numbness and a loss of reflexes.
Unlike some other conditions that cause weakness and paralysis, GBS is a symmetrical, ascending paralysis – it starts in your toes and fingers and moves up your legs and arms.
What Causes Guillain-Barré Syndrome?
GBS is an autoimmune disorder and often starts after a viral or bacterial infection, especially one that causes diarrhea or a respiratory illness.
One of the biggest risk factors is a previous Campylobacter jejuni infection, that is often linked to drinking raw milk, eating undercooked food, drinking untreated water, or from contact with the pet feces.
In less half of cases, no specific cause is found.
Fortunately, although progress can be slow, many people with GBS recover.
“On very rare occasions, they may develop GBS in the days or weeks after getting a vaccination.”
CDC on Guillain-Barré syndrome and Flu Vaccine
It is not common though.
For example, the increased risk of GBS after getting a flu vaccine is thought to be on the order of about one in a million – in adults.
Flu vaccines have not been shown to cause GBS in children.
“The risk of GBS is 4–7 times higher after influenza infection than after influenza vaccine. The risk of getting GBS after influenza vaccine is rare enough that it cannot be accurately measured, but a risk as high as one case of GBS per 1 million doses of flu vaccine cannot be reliably excluded.”
Poland et al on Influenza vaccine, Guillain–Barré syndrome, and chasing zero
It is also important to keep in mind that you are far more likely to get GBS after a natural flu infection than after the vaccine, plus the flu vaccine has many other benefits.
What about other vaccines?
“In this large retrospective study, we did not find evidence of an increased risk of GBS following vaccinations of any kind, including influenza vaccination.”
Baxter et al on Lack of association of Guillain-Barré syndrome with vaccinations
No other vaccines that are currently being used routinely have been associated with Guillain-Barré syndrome.
In fact, many studies do not even find an association between GBS and the flu vaccine.
What to Know About Guillain-Barré Syndrome and Vaccines
Guillain-Barré Syndrome may be associated with the flu vaccine in adults in about 1 in a million cases, but does not occur with any other vaccines, and occurs far more commonly after a natural flu infection.
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?
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 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.
“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.
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.
Just about any side effect after a vaccine can be scary for parents.
What if your child suddenly became limp, wasn’t responsive, and was pale?
That would be scary for any parent.
What Are Hypotonic-Hyporesponsive Episodes?
But that’s just what can happen when a child has a hypotonic–hyporesponsive episode (HHE).
“A hypotonic-hyporesponsive episode (HHE) is the sudden onset of hypotonia, hyporesponsiveness, and pallor or cyanosis that occurs within 48 hours after childhood immunizations.”
DuVernoy et al on Hypotonic-hyporesponsive episodes reported to the Vaccine Adverse Event Reporting System (VAERS), 1996-1998
These types of episodes were once thought to happen once for every 1,750 DTP vaccines given.
Fortunately, although they certainly do sound scary, the episodes stop on their own and don’t cause any permanent harm.
Hypotonic-hyporesponsive episodes were even removed as table injuries after DTP back in 1995. It is not that HHE can’t occur after DTP, DTaP, or other vaccines, but rather that HHE doesn’t then cause any permanent neurological damage to the child.
And it is rare for kids to have a second episode, so they can continue to get vaccinated. HHE is not a good reason to skip or delay all of your child’s vaccines. While not a contraindication to getting vaccinated, having an episode of HHE “within 48 hours after receiving a previous dose of DTP/DTaP,” is listed as a precaution to getting another dose of DTaP or Tdap though.
“In general, vaccinations should be deferred when a precaution is present. However, a vaccination might be indicated in the presence of a precaution if the benefit of protection from the vaccine outweighs the risk for an adverse reaction.”
CDC on Vaccine Contraindications and Precautions
Also, HHE has become even more rare since we switched to using DTaP, instead of the older DTP vaccine. So being worried about HHE is definitely not a good reason to skip or delay any vaccines.
What to Know About Hypotonic-Hyporesponsive Episodes
Hypotonic-hyporesponsive episodes were more common after the older DTP vaccines, but still didn’t cause any long term problems and aren’t a good reason to skip or delay your child’s vaccines.
It is not uncommon to hear about parents having ‘panic attacks’ over the idea of vaccinating their kids.
“…many parents are inundated with horror stories of vaccine dangers, all designed to eat away at them emotionally while the medical and scientific communities have mounted their characteristic response by sharing the facts, the data, and all of the reliable peer-reviewed and well-cited research to show that vaccines are safe and effective.”
Federman on Understanding Vaccines: A Public Imperative
“…recognizes the importance of examples—testimonials and stories—that are the lifeblood of vaccine-hesitant beliefs.”
Nathan Rodriguez on Vaccine-Hesitant Justifications
Vaccine injury stories aren’t new though.
These types of anecdotal stories were very popular when folks used to think that the DPT vaccine was causing a lot of side effects. It wasn’t though. And it was soon proven that the DPT vaccine didn’t cause SIDS, encephalitis, non-febrile seizures, and many other things it was supposed to have caused.
“Anecdotes – about a new miracle cure, a drug that is not being made available on the NHS, or the side effects of treatment, or some environmental hazard – sell product. Data, on the other hand, which take us towards the truth about these things, are less popular. Anecdotes, however many times they are multiplied, do not point the way to reliable knowledge. As the aphorism says, “The plural of anecdote is not data”.”
Raymond Tallis on Anecdotes, data and the curse of the media case study.
That anecdotes “sell” better than data may be one reason why you see them so often on anti-vaccine websites. Another is that they simply don’t have any good data to use as evidence!
Are Vaccine Injury Stories True?
Vaccines are not 100% safe, so there is no doubt that some vaccine injury stories are true.
There is also no doubt that what many people perceive to be vaccine injuries have actually been proven to not be caused by vaccines, from allergies and eczema to autism and MS.
“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
Also keep in mind that in addition to the many so-called vaccine induced diseases, there are many historical vaccine injury stories that have been shown to be untrue:
Johnnie Kinnear supposedly began having seizures 7 hours after getting a DPT vaccine, when he was 14-months-old, but medical records actually shown that his seizures started 5 months after he received his vaccines
Dravet syndrome now explains many severe seizures associated with vaccinations
And at least one of Wakefield’s own followers – a mother who claimed that the MMR vaccine caused her son’s autism, was “dismissed as a manipulative liar” by a court in the UK.
Vaccine Injury Stories are Dangerous
Do vaccine injury stories have a purpose? They might help a parent cope with a diagnosis in the short term, but vaccine injury stories are dangerous in so many ways.
We have seen how they create anxiety for many parents, which can scare them away from vaccinating and protecting their kids from life-threatening vaccine-preventable diseases.
What else can they do?
They can certainly build up mistrust towards pediatricians and other health professionals. That is one way that the anti-vaccine movement continues to hurt autistic families. They also can lead parents to think that their “vaccine injured” child is “damaged” in some way.
And they push parents towards dangerous, unproven, unnecessary, and expensive alternative treatments. It shouldn’t be a surprise that many of the sites and forums that push vaccine injury stories also promote a lot of dangerous advice.
They are not 100% safe though and they can have some side effects.
“Considering that the vaccines in the infant schedule are administered to millions of children each year, the list of known adverse events, even rare ones, is impressively short.”
O’Leary et al on Adverse Events Following Immunization: Will It Happen Again?
Fortunately, most of these side effects are harmless and don’t have any long term risks. And of course, the great benefits of vaccines outweigh those risks.
Common Vaccine Reactions
Although most kids don’t have any reactions at all, some do have mild reactions.
Among the possible vaccine reactions or side effects that can occur include:
redness or swelling at the injection site
soreness or tenderness at the injection site
chills and sore joints
swelling of glands in the cheeks or neck
How commonly do they occur?
These side effects depend on the vaccine that was received and can range from 1 in 3 kids for some fussiness all the way down to 1 in 75 kids for kids who have swelling of their glands.
And they usually begin 1 to 3 days after the vaccine was given and last for 1 to 7 days. Fortunately, fever and fussiness don’t last that long, typically going away after just a day or two.
Keep in mind that some reactions are more delayed though. This is especially true for the MMR vaccine, in which mild reactions, like a fever, rash, or swelling of glands might not occur until 6 to 14 days after a child got his vaccine.
What can you do if your child has a mild vaccine reaction?
Consult your health care provider, but keep in mind that treatment is often symptomatic, typically with a cold pack or cool cloth/compress for local reactions and pain reliever.
Fainting also commonly occurs after vaccines, especially in teens, but it is thought to be due to the vaccination process itself and not the vaccines. Still, it is something to be aware of.
What About More Moderate Reactions?
More moderate reactions after vaccines are fortunately more uncommon.
“There is low public tolerance of vaccine adverse reactions. Vaccines are therefore only licensed when the frequency of severe reactions is very rare and when only minor, self-limiting reactions are reported.”
All of these reactions, as well as the risks of getting a natural infection, are listed in each vaccine’s VIS. The Vaccine Information Statements also includes information on how to report all possible vaccine side effects to VAERS.
What to Know About Common Vaccine Reactions
While most kids don’t have any reactions at all after their vaccines, those that do typically have mild reactions, including some fever, soreness, or swelling at the injection site. More moderate and severe reactions are rare.
Vaccines are very safe, but they are not 100% risk free.
They are certainly not as high risk as some anti-vaccine folks will have you believe though.
“Vaccine hesitation is associated with perceived risk. Since vaccine-preventable diseases are rare, an adverse event from a vaccine is perceived by the parent to be of greater risk. Risk perception is critical.”
AAP on Addressing Common Concerns of Vaccine-Hesitant Parents
And when you consider their great benefits, it is easy to see why the great majority of parents get their kids fully vaccinated and protected against all recommended vaccine-preventable diseases.
Risk Perception and Vaccine Hesitancy
Even though the risks and side effects of vaccines are very low, some people think that they are much higher. This is often amplified because of vaccine scare stories and the misinformation found on anti-vaccine websites.
“No intervention is absolutely risk free. Even the journey to a physician’s office with the intention to receive a vaccination carries the risk of getting injured in an accident. With regards to risks of vaccination per se, one has to distinguish between real and perceived or alleged risks.”
Heininger on A risk–benefit analysis of vaccination
can be more likely to avoid risks that are associated with an action or having to do something vs. those that involve doing nothing or avoiding an action, even if inaction (skipping or delaying a vaccine) is actually riskier
often think about risks based on their own personal experiences (you remember someone’s vaccine injury story), rather than on scientific evidence
“As much previous research claims, this study confirms that individuals characterized by greater trust of healthcare professionals and the possession of more vaccine-related knowledge perceive higher levels of benefits and lower levels of risks from vaccinations.”
Song on Understanding Public Perceptions of Benefits and Risks of Childhood Vaccinations in the United States
Most vaccines have some common, mild side effects, which might include (depending on the vaccine):
fever, typically low-grade
redness or swelling where the shot was given
soreness or tenderness where the shot was given
tiredness or poor appetite
How commonly do they occur?
It depends on the vaccine and side effect, but they range from about 1 in 50 to 1 in 3 people. These side effects are typically mild and only last a day or two. And they don’t cause lasting problems.
While not all possible side effects are mild, those that are more moderate or severe are much more uncommon. Febrile seizures, for example, only happen after about 1 out of 3,000 doses of MMR and some other vaccines. And while scary, febrile seizures, crying for 3 hours or more, or having a very swollen arm or leg, some other uncommon vaccine side effects, also don’t cause lasting problems.
Fortunately, the most severe side effects, including severe allergic reactions, are only thought to happen in less than 1 out of a million doses. And although these types of severe reactions can be life threatening, they are often treatable, just like severe allergic reactions to peanuts. For others, like encephalitis, although they are table injuries, it isn’t clear that they are even side effects of vaccines, since they occur so rarely.
“No medical product or intervention, from aspirin to heart surgery, can ever be guaranteed 100% safe. Even though we will never be able to ensure 100% safety, we know that the risks of vaccine-preventable diseases by far outweigh those of the vaccines administered to prevent them.”
World Health Organization
In addition to side effects, some other risks of getting vaccinated might include that your vaccine didn’t work, after all, although vaccines work very well, they are not 100% effective. You might also, very rarely, be given the wrong vaccine or the right vaccine at the wrong time.
Any small risks of getting vaccinated, including side effects that are often mild, are not a good reason to think about skipping or delaying a vaccine, especially when you thoughtfully consider all of their great benefits.
Anti-vaccine folks claim that an awful lot of things are encephalitis, from crying excessively after getting a vaccine to autism.
Although the Vaccine Information Statement for the DTaP vaccine (it was more common after the older DTP vaccine) does state that children may uncommonly have “non-stop crying, for 3 hours or more” it is not because they have brain inflammation, and the reaction “although unnerving, is otherwise benign.” It is not even a contraindication to getting another dose of DTaP or a later dose of Tdap.
What causes this non-stop crying? It is thought to be a painful local reaction. Fortunately, it does not happen as often with the newer DTaP vaccines.
And autism is not encephalitis.
“That measles infections can cause neurologic side effects on rare occasions is known, but the complication rate for vaccinations is low. After infectious measles encephalitis, risk of an autistic regression has occurred in 1/1000 to 1/10,000 cases. If the trend toward delaying vaccination continues because parents remain misinformed about the MMR, the number of children with neurologic complications of measles or rubella will increase. ”
Chez et al on Immunizations, Immunology, and Autism
Can encephalitis lead a child to have symptoms of autism?
In addition to natural measles infections, there have been reports of children developing autism after HSV encephalitis, varicella encephalitis, congenital rubella syndrome, and congenital syphilis.
But the great majority of kids with autism do not first have encephalitis. They do not have ongoing brain inflammation.
Saying that encephalitis can cause autism is not the same thing as saying that autism is encephalitis.
Do Vaccines Cause Encephalitis?
And even though encephalitis has long been a table injury for a few vaccines, the 2012 IOM report, “Adverse Effects of Vaccines: Evidence and Causality,” found inadequate evidence to be able to conclude that encephalitis was caused by vaccines.
“Follow-up investigations in that cohort and others, however, found no evidence of a real increased incidence of encephalitis following DTwP. In addition, the most recent IOM report concludes that the evidence is inadequate to accept or reject a causal relationship between diphtheria toxoid-, tetanus toxoid-, or acellular pertussis-containing vaccine and encephalitis or encephalopathy.”
Vaccinophobia and Vaccine Controversies of the 21st Century
That’s not surprising, because follow-up of children studied in the 1980s, from which the original claims about DTP and encephalitis were made, found no evidence of an increased risk of encephalitis.
What about the MMR vaccine?
Again, the IOM report found inadequate evidence, but the problem has always been that “acute encephalitis post-MMR is so rare that it has been impossible to distinguish from the background encephalitis rate of 1 in one million in immune competent hosts.”
Doesn’t the discovery of anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis prove that vaccines cause autism?
“Anti-NMDA receptor encephalitis is a disease occurring when antibodies produced by the body’s own immune system attack NMDA receptors in the brain.”
The Anti-NMDA Receptor Encephalitis Foundation
Often associated with tumors, isolated case reports do correlate anti-NMDAR encephalitis with vaccines. There are so few cases of anti-NMDAR encephalitis though, it is hard to know what they mean, as are the reports of autism developing after anti-NMDAR encephalitis.
What to Know About Vaccines and Encephalitis
Vaccines still don’t cause autism and the latest safety studies report that vaccines probably don’t cause encephalitis, although a few are still listed as a table injury.