Breaking News – 158 cases of AFM in 36 states have been confirmed so far this year, with an additional 153 cases under investigation.
Since 2014, we have seen several outbreaks of acute flaccid paralysis (the sudden onset of weakness in one or more arms or legs) across the United States.
We don’t know, except we do know that these folks don’t have polio, even though folks continue to get confused because the kids are described as having a “polio-like” disease. Every case undergoes extensive testing, including testing for polio and other viral infections.
Do Vaccines Cause Acute Flaccid Myelitis?
Tragically, like some other conditions of unknown cause, some people have grasped onto the idea that AFP could be caused by vaccines.
“Of 14 patients with available information, 12 had previously received polio vaccine; one child and one adult were unvaccinated because of personal belief exemptions.”
Acute Flaccid Paralysis with Anterior Myelitis — California, June 2012–June 2014
It shouldn’t be surprising that there is absolutely no evidence that this is any type of vaccine injury.
Of nearly 350 cases of the acute flaccid myelitis (AFM), or the subtype of AFP that we have been seeing since 2014, we know that:
- most cases occur in children
- they have a magnetic resonance image (MRI) showing spinal cord lesion largely restricted to gray matter and spanning one or more vertebral segments
- AFM can be caused by viruses, environmental toxins, and genetic disorders, although no common etiology has been found in recent cases
- cases are occurring sporadically – after 120 cases in 34 states in 2014, there were only 24 cases in 17 states in 2015, but then 149 cases in 39 states in 2016 and 33 cases in 16 states in 2017. And there have been at least 62 cases in 22 states in 2018.
- most cases occur in the late summer and early fall
- most had symptoms of a preceding viral illness, including respiratory symptoms or diarrhea
- some were unvaccinated
- the ages of affected children has ranged from 5 months to 20 years
- some patients have recovered, while others have persistent paralysis
- there has been at least one death
- some, but not all, were positive for enterovirus D68
- in Colorado this year, 9 of 14 cases were linked to EV-A71 infections
- although there was a national outbreak of EV-D68 in 2014 that coincided with the first AFM cases, we didn’t see this kind of outbreak in the following years
So what’s causing these kids, with a median age of about 7 years, to develop acute flaccid myelitis?
We don’t know, but there is certainly no reason to think that it could be a vaccine, as some anti-vaccine folks suggest.
For one thing, several of the kids were completely unvaccinated!
And then, if it was a vaccine, why the seasonal pattern?
And why don’t cases occur in all states and at the same rates each year?
Also, why the big range in ages? After all, what vaccines do a 5 month old and a 20 year old have in common?
And the CDC has been looking at all possible causes.
“Our medical team has been reviewing vaccine records when available during this year’s investigation and do not see a correlation.”
Kristen Nordlund, CDC spokeswoman
Acute flaccid myelitis is not caused by vaccines. Hopefully we will soon find out what really is causing it and can figure out how to prevent it.
Want to prevent a type of acute flaccid paralysis right now?
While AFM is a type of non-polio AFP, we have long had a vaccine that can prevent polio, which also causes acute flaccid paralysis.
More on Vaccines and Acute Flaccid Paralysis
- CDC – Transcript for CDC Telebriefing: Update on Acute Flaccid Myelitis (AFM) in the U.S.
- Paralyzing polio-like illness mainly affecting children confirmed in 22 states, CDC says
- Why health care providers & public health professionals say vaccines are not the cause of recent acute flaccid myelitis (AFM) cases
- Polio-like syndrome – blame enterovirus 68 not vaccines
- Acute flaccid paralysis of unknown etiology in California
- WHO-recommended surveillance standard of poliomyelitis
- Polio-like paralysis in California
- CDC cites 2 more deaths in EV-D68 cases, more polio-like illnesses
- Study – Enterovirus D68 and acute flaccid myelitis-evaluating the evidence for causality.
- AAP – No common etiology, treatment found for acute flaccid myelitis
- CDC – About Acute Flaccid Myelitis
- CDC – AFM Investigation
- CSTE Standardized Case Definition for Acute Flaccid Myelitis
- MMWR – Acute Flaccid Paralysis with Anterior Myelitis — California, June 2012–June 2014
- MMWR – Enterovirus D68 Infection in Children with Acute Flaccid Myelitis, Colorado, USA, 2014
- MMWR – Severe Respiratory Illness Associated with Enterovirus D68 — Missouri and Illinois, 2014
- MMWR – Acute Flaccid Myelitis Among Children — Washington, September–November 2016
- MMWR – Notes from the Field: Cluster of Acute Flaccid Myelitis in Five Pediatric Patients — Maricopa County, Arizona, 2016
- Study – Acute Flaccid Myelitis in the United States, August-December 2014: Results of Nationwide Surveillance.
- Study – Acute flaccid myelitis: A clinical review of US cases 2012-2015.
- Study – A cluster of acute flaccid paralysis and cranial nerve dysfunction temporally associated with an outbreak of enterovirus D68 in children in Colorado, USA.
- Study – Notes from the Field: Acute Flaccid Myelitis Among Persons Aged ≤21 Years — United States, August 1–November 13, 2014
- CDC – About Acute Flaccid Myelitis
- CDC – Non-Polio Enterovirus
- Acute Flaccid Paralysis (AFP) Surveillance
- India’s Victory Over Polio Has an Unexpected Consequence
- Study – Eradicating poliomyelitis: India’s journey from hyperendemic to polio-free status
- Report – The Spatial Dynamics of Poliomyelitis in the United States: From Epidemic Emergence to Vaccine-Induced Retreat, 1910–1971
- Study – Antigenic Diversity of Enteroviruses Associated with Nonpolio Acute Flaccid Paralysis, India, 2007–2009
- Transverse Myelitis Association
- Six Minnesota kids suffer rare, polio-like disorder
- States and CDC probe reports of rare poliolike symptoms in kids
Updated December 10, 2018
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