Tag: correlation

Vaccines and SIDS

Rates of most causes of sudden infant death, including SIDS, have dropped since the mid-1990s.
Rates of most causes of sudden infant death, including SIDS, have dropped since the mid-1990s.

Long before Andy Wakefield scared parents with the idea that vaccines could be linked to autism, we had the myth that vaccines caused SIDS or sudden infant death syndrome.

SIDS

SIDS is the “cause assigned to infant deaths that cannot be explained after a thorough case investigation, including a scene investigation, autopsy, and review of the clinical history.”

Like other types of sudden unexpected infant death (SUID), including sleep related deaths, the incidence of SIDS decreased dramatically in the mid-1990s after the American Academy of Pediatrics introduced their safe sleep recommendations.

These recommendations have evolved over the years, which is now called Safe to Sleep, and now include advice about room sharing instead of bedsharing, the protective role of breastfeeding and getting immunized, avoiding overheating, using pacifiers, and getting regular prenatal care, etc.

Vaccines and SIDS

The fact that getting immunized is thought to have a protective role against SIDS should help folks understand that vaccines do not cause SIDS.

“There is no evidence that there is a causal relationship between immunizations and SIDS. Indeed, recent evidence suggests that vaccination may have a protective effect against SIDS.”

AAP Task Force on Sudden Infant Death Syndrome

It is very easy to see why some would think they could be linked though. The highest risk of SIDS coincides with the ages of the two and four month well child checks, when infants are vaccinated. But as many of us understand, correlation does not imply causation. Just because two things happen at the same time doesn’t mean that one caused the other.

It also didn’t help that in 1999, ABC’s 20/20 did a misleading episode, “Who’s Calling the Shots?,” which claimed that the hepatitis B vaccine could cause SIDS.

But it is easy to see that they were wrong.

For one thing, even as we are giving infants more vaccines and protecting them from more diseases, fewer infants are dying of SIDS. How can that be if vaccines are linked to SIDS?

And why is the infant mortality rate in the United States continuing to go down, recently reaching a record low?

Also, many studies, such as this one, “Probability of Coincident Vaccination in the 24 or 48 Hours Preceding Sudden Infant Death Syndrome Death in Australia,” showed that coincident vaccination and SIDS can be expected to occur by chance alone. In fact, for the infants in this study, they showed that “if a child experienced an illness at the age of 8 weeks, then there is a 7% chance (or probability of 0.07) that the child would have been vaccinated in the preceding 24 hours.”

“…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 Six Common Misconceptions About Immunization

And other studies actually showed that getting vaccinated reduced an infant’s risk of dying of SIDS.

What To Know About Vaccines and SIDS

Vaccines do not cause SIDS.

In fact, getting vaccinated is now thought to have a protective effect against SIDS!

For More Information on Vaccines and SIDS

Vaccines and Seizures

A newborn baby getting an EEG.
A newborn baby getting an EEG.

Can vaccines cause seizures?

Unfortunately, they sometimes can.

Vaccines and Febrile Seizures

The CDC reports that “There is a small increased risk for febrile seizures after MMR and MMRV vaccines.”

We also know that:

  • there is a small increased risk for febrile seizures when the influenza vaccine is given at the same time as either the Prevnar13 vaccine or the DTaP vaccine, although “the risk of febrile seizure with any combination of these vaccines is small and CDC’s Advisory Committee on Immunization Practices (ACIP) does not recommend getting any of these vaccines on separate days.”
  • there is a small increased risk for febrile seizures if the combined MMR and chicken pox vaccine (ProQuad) is given to infants between the ages of 12 to 23 months vs their getting the shots separately.

But remember that febrile seizures, while scary for parents and other caregivers, are rarely dangerous.

It is also important to note that while febrile seizures are common, they are not commonly triggered by vaccines. A 2016 report in Pediatrics, “Vaccines and Febrile Seizures: Quantifying the Risk,” states that “The risk is 1 febrile seizure per pediatric practice every 5 to 10 years.”

Not surprisingly though, vaccines can likely prevent many febrile seizures, as chicken pox, flu, Hib, measles, mumps, rubella, pneumococcal infections and other vaccine-preventable diseases often cause fever and can trigger febrile seizures themselves.

Also, a study recently found that children who got sick with pertussis could be at increased risk for developing epilepsy, or recurrent seizures. That’s just another good reason to get vaccinated and protected against vaccine-preventable diseases.

Vaccines and Other Types of Seizures

While vaccines can sometimes trigger febrile seizures, they do not typically cause other types of seizures.

It was once thought that seizures were a common side effect of the DPT vaccine, but many studies have found that to not be true and seizures following DPT was even removed as a table injury from the NVICP. In fact, many of these children were instead found to have Dravet syndrome, which put them at increased risk for febrile seizures.

Long-term non-febrile seizures are still listed as side effects for the DTaP and MMR vaccine, but they “are so rare it is hard to tell if they are caused by the vaccine.”

A 2010 study in Pediatrics, “Lack of Association Between Acellular Pertussis Vaccine and Seizures in Early Childhood,” did not find any “increased risk for seizures after
DTaP vaccination among children who were aged 6 weeks to 23 months.”

Do report any reaction to VAERS if you think it was caused by a vaccine though.

Seizures After Getting Vaccines

If vaccines don’t usually cause seizures, then how do you explain a healthy infant developing seizures a few days, weeks, or months after getting his vaccines?

We’re always looking for reasons why something happened. The example I use is from my wife, who is a pediatrician. She was about to vaccinate a four-month-old baby, and while she was drawing the vaccine from the syringe, the baby had a seizure — and went onto have a permanent seizure disorder. Now, my wife hadn’t given the vaccine yet. But if she had given that vaccine five minutes earlier, there would have been no amount of statistical data in the world that would have convinced that mother that the vaccine hadn’t caused the baby’s seizure. You can do studies that show no increased risk with vaccines and seizure disorders, but that mother might still say “well, that’s true for the population but it’s not true for my child.”

Temporal associations are powerful, and they’re hard to defeat with statistics or studies.

Paul Offit, MD interview for The Thinking Persons Guide to Autism

There are many seizure disorders that begin in infancy.

Some even start in the newborn period, before a baby is a month old.

They are not triggered by vaccines though.

They include:

  • Infantile Spasms (first described in 1841) – typically begin when infants are about 4 months old, just when they get their second set of vaccines, which weren’t available when Dr. West described his own son’s repeated spasms
  • Benign Familial Neonatal Seizures – often genetic, seizures may begin on a baby’s third day of life
  • Benign Neonatal Convulsions – begin on the fifth day of life – the “fifth day fits,” and the seizures stop in about a month

If your child got her first hepatitis B vaccine when she was five days old and began having seizures, would you accept a diagnosis of Benign Neonatal Convulsions or would you blame the shot?

Would you remember the saying about correlation and causation?

For More Information on Vaccines and Seizures: