“…the increased risk of disease in the pediatric population, in part because of increasing rates of vaccine refusal and in some circumstances more rapid loss of immunity, increases potential exposure of immunodeficient children.”
Medical Advisory Committee of the Immune Deficiency Foundation
You may have heard of the Polio Pioneers, the kids who got Jonas Salk‘s original inactivated polio vaccine in 1954.
They were part of a large clinical trial, getting either the polio shot or a saline placebo, and helped prove that the vaccine was safe and effective.
Do You Remember Sabin Sundays?
Of course, that wasn’t the end of the story though.
After the Cutter Incident, Albert Sabin soon proved that his live, oral polio vaccine was better than Salk’s inactivated polio vaccine.
And it was first given in the United States on April 24, 1960 – the first Sabin Sunday, when 20,000 children came to Cincinnati Children’s to receive his sugar cube vaccine.
“On three consecutive Sundays — “Sabin Sundays” — in 1960, millions of families lined up at churches and schools across the country to swallow a spoonful of pink syrup or a sugar cube treated with a life-saving polio vaccine, developed by UC researcher Albert Sabin.”
Sabin Sunday, 1960
Sabin Oral Sunday immunization programs continued over the next few years all over the country as kids got caught up on their polio vaccines.
Can you imagine taking your kids to school to get them vaccinated on a Sunday?
Millions of parents did it!
Newspapers urged folks to attend the Sabin on Sunday clinics to help end the threat of “crippling poliomyelitis.”
They lined up to get their kids vaccinated and protected.
As more people are vaccinated and diseases disappear, they forget how bad those diseases are, skip or delay getting their vaccines, and trigger outbreaks. Photo by WHO
They aren’t, but you can kind of understand why they might think that with a disease like polio, when they might never actually have known anyone to have the disease.
What Is the Morbidity/Mortality Rate of the Polio Vaccine vs the Wild Virus?
Still, even though polio is under good control and close to being eradicated, the risk/benefit ratio clearly favors getting vaccinated and protected.
That’s because the polio vaccines are very safe and if we stopped vaccinating, polio could come back.
In fact, morbidity/mortality from polio vaccines are decreasing, as we are using much less oral polio vaccine (OPV) in the transition (OPV cessation) to just using inactivated polio vaccine (IPV).
“Over the past ten years, more than 10 billion doses of OPV have been given to nearly three billion children worldwide. More than 16 million cases of polio have been prevented, and the disease has been reduced by more than 99%. It is the appropriate vaccine through which to achieve global polio eradication.”
OPV Cessation
And while most developed countries already use IPV, those that are still using OPV recently switched from a trivalent (tOPV) to a bivalent (bOPV) form of OPV. We could do this because type 2 poliovirus has already been eradicated (2015)!
Of course, the issue with the OPV vaccines is that they rarely cause vaccine-associated paralytic polio (VAPP) and circulating vaccine-derived polioviruses (cVDPV).
Fortunately, this is even less common with bOPV.
As this chart from the WHO shows, polio vaccines are very safe.
So morbidity (getting sick)/mortality (dying) from polio vaccines is low.
There were only 31 cases of wild polio in 2018, in Afghanistan and Pakistan, and an additional 102 cases of cVDPV in 7 countries.
What about morbidity/mortality from polio?
“As recently as 30 years ago, wild poliovirus paralysed more than 350 000 children in more than 125 countries every year. In 2018 there were fewer than 30 reported cases in just two countries – Afghanistan and Pakistan.”
“Zero polio transmission and health for all”, WHO Director-General gives new year’s wish to the people of Afghanistan and Pakistan
With a 99.9% drop in polio cases since 1998, your risk of getting polio in most parts of the world is very low, but you still have to consider both the morbidity/mortality of polio in the pre-vaccine era and the risk of polio returning if we stop vaccinating before it is eradicated.
What about the idea that you don’t have to worry about polio because only 1% of kids with polio developed paralysis?
“The mortality rate for acute paralytic polio ranges from 5–15%.”
Disease factsheet about poliomyelitis
Well, when everyone gets polio, even 1% is a lot.
With such a safe vaccine, why put your kids at risk of getting polio?
Do you even understand what the risks are?
No, it isn’t just the risk of wild polio in Afghanistan and Pakistan.
Since the oral polio vaccines shed, if you are unvaccinated, in addition to the risk of wild polio, there is a small risk of getting circulating vaccine-derived polioviruses (cVDPV) if you are not vaccinated and protected. No, it is not a big risk, as there were only 102 cases of cVDPV in 7 countries in 2018, but it isn’t zero either.
And the other big risk is that if enough folks stop getting vaccinated, taking their chances hiding in the herd, polio will come back and our chance to eradicate another vaccine-preventable disease will fail.
More on the Morbidity and Mortality Rates of Polio
It’s true, polio has been eliminated in the United States.
Are these folks serious with this anti-vaccine nonsense?
But that doesn’t mean that we can stop vaccinating kids against polio yet.
Why Do We Still Vaccinate If Polio Has Been Eliminated?
For one thing, the last polio case in the United States was a lot more recent than 40 years ago.
What happened 40 years ago?
That was when we had the last endemic case of polio in the United States, in 1979. After that, in addition to cases of VAPP, there were at least 6 cases of imported paralytic poliomyelitis. In fact, the last case of wild polio in the United States was in 1993, just 26 years ago.
And just ten years ago, in 2009, was the very last case of VAPP, a patient with a long-standing combined immunodeficiency who was probably infected in the late 1990s, even though she didn’t develop paralysis until years later.
But still, why couldn’t we stop vaccinating against polio in the United States, even though polio isn’t eradicated yet? After all, we stopped using the smallpox vaccine in 1972, before smallpox was declared eradicated (1980).
While that is true, smallpox isn’t as contagious as polio and there hadn’t been a case of smallpox in the United States for over 30 years when we stopped using the vaccine.
Until wild polio is eradicated and the oral polio vaccine isn’t used anymore (OPV switch), we must continue to vaccinate against polio to prevent new outbreaks.
That is the polio eradication and endgame strategic plan.
Over the next few years, the world will hopefully switch to using just the injectable form of the polio vaccines, which eliminates the risk of VAPP.
But if we are so close, why not just stop vaccinating in those parts of the world that don’t have polio?
Because we are so close to eradicating polio.
Why take the risk of polio spreading from one of the remaining endemic countries, paralyzing kids, and putting eradication efforts further behind?
Let’s continue the work and eradicate polio, once and for all!
And for the record – we don’t pump “kids full of polio” when we give them a polio vaccine. The polio shot is an inactivated vaccine, so doesn’t contain live polio virus.
More on Why Do We Still Vaccinate If Polio Has Been Eliminated?
