The infecting polio virus was a live oral polio vaccine strain mutated back to virulence.
The live oral polio vaccine is no longer used in the US because of this risk, but is used in some other countries. An inactivated virus vaccine is used in the US.
The patient did not have recent travel history.
It is possible that the virus was imported into the US through travel, then spread in the community to the patient.
While the live oral polio vaccine is easy to administer, and the risk of back mutation to virulence is small, making it commonly used in places where polio is endemic, the risk of back mutation to virulence makes it less preferred in places like the US where polio has been eliminated or close to eliminated. Hence, the inactivated virus vaccine is used in the US.
If you are unsure of your polio immunity status, you may want to consider checking that or getting the inactivated virus vaccine.
One of my first questions when I see my doctor is whether a vaccination from 60 years ago is still effective, or if those of us who were vaccinated that long ago should get a booster. From what I just found on the CDC web site it appears that a booster is probably not needed.
However, this does remind us that all of us should have been vaccinated for polio. It is not gone.
This is very sad. Polio was nearly eradicated. Apparently it shares with smallpox the relatively unusual feature that only humans can get it, which makes eradication possible. With the current anti-vaccine hysteria, it seems very unlikely that we will be able to get this done.
According to another news source, the patient is a 20 year old Orthodox Jewish man who had traveled to Hungary and Poland. Nationally, more than 92% of children are fully vaccinated by age 2. Last year, Rockland County’s rate of completion of the childhood vaccination schedule, which protects against a range of diseases, was 42%, the lowest in the state.
I was surprised to hear this news yesterday because I thought polio had been eradicated from pretty much everywhere.
I checked the CDC website and it says that the only remaining countries with polio cases are Pakistan and Afghanistan. Not anymore I guess
I’d be interested in knowing how this gentleman contracted the virus.
DH and I both had BOTH the oral polio and shot polio vaccines as children. Nevertheless, we were required to have a polio shot booster before traveling to some countries in Africa in 2011. We went to an international immunization clinic…and this was on the list of vaccines we needed.
This NY person…sounds like they had no polio vaccines of any kid at all.
The risk factor is that someone else received the live oral polio vaccine (while not in the US, since the oral polio vaccine is not used in the US), and passed the virus on to others (either directly to the patient, or through intermediary contacts). The oral polio vaccine viruses passed on this way would ordinarily just vaccinate those it infects, but occasionally it mutates back into a virulent form that can cause paralysis, which appears to be the case here.
Actually, chimpanzees can get it, as Jane Goodall documented a polio outbreak in chimpanzees that she was studying. She also gave them bananas with oral polio vaccine in them to stop the outbreak.
But the chimpanzee population is much smaller than the human population.
It does seem unlikely that community transmission of the oral polio vaccine virus has been going on in the US for 22 years since its use was discontinued in the US.
The unvaccinated US man traveled outside the US to Eastern Europe. There, he was exposed to a strain of polio from the live attenuated vaccine, that had mutated back to being virulent. Back when the US was using live attenuated polio vaccine, we had about 4-8 cases a year of polio in infants with severe combined immunodeficiency (immunized with live attenuated oral polio vaccine before they had been diagnosed), but virtually no one else. Eventually the US got to the point where the rate of immunization against polio was so high that the tiny risk of vaccine-induced polio outweighed the cost of switching over to inactivated, injected polio vaccine.
Now, between vaccines having been delayed by the pandemic, and increasing vaccine refusal, there may be enough of a reservoir of unimmunized people in the US for something like polio to spread. Unfortunately, for some people, immunization refusal has become akin to a religious principle, where they fear immunization more than death from vaccine-preventable diseases.
At this point, how it happened is kind of irrelevant. What is relevant is the extremely low rate of immunization in certain groups, because they choose to decline vaccines. This has left us vulnerable to a resurgence of vaccine-preventable diseases, even among those who appropriately immunize their kids, but whose children are young enough to not yet be fully immunized - measles, chicken pox, polio, diphtheria, whooping cough. We’re losing herd immunity, which puts everyone’s infants at risk.
One can accelerate the normal immunization schedule within the limits of the guidelines. Begin at 6 weeks old, and have a set of immunizations every 6 weeks, so that the infant has received the full primary series by about 4.5 months old, rather than 6 months old. Give the first MMR and chicken pox at 12 months, and the second dose two months later, for full protection by 15 months old - and during measles outbreaks, MMR can be given as early as 6 months old.
As for those who neglect or decline to immunize, it’s pretty clear that polio is no longer a disease of the past. So sad. We were SO close to eliminating wild-type polio, so that it would go the way of small pox, by about 2016. But there was ignorant local resistance to vaccines in Afghanistan and Pakistan, promoted by religious leaders, who preached that the polio vaccination campaign was an attempt to sterilize Muslim girls. Islamist gunmen have murdered local vaccine workers in Nigeria, Afghanistan, and Pakistan. Now wild-type polio is spreading again, along with vaccine-derived polio strains from back-mutated vaccine strains. Be it trendy vaccine-refusal, the pandemic isolation, or violent opposition interfering with immunization, polio is no longer a disease of the past.
My mom was an RN who worked in a polio ward with patients in iron lungs. When our S was immunized with live polio while my mom was undergoing chemo, we chose to keep him away from her. Mom knew first hand what an awful disease polio is, so we were not taking any chances.
Does anyone know if we were looking for it’s spread before a clinical case arose? Since so many cases produce no symptoms at all, it seems possible if we weren’t looking until a case with symptoms arose.
