The live oral polio vaccine is mutating and replicating wild polio.
Polio is rare, very rare thanks to modern medicine. However, for the first time ever mutated forms of the oral polio vaccine paralyzed more people than wild polio. Yesterday, NPR came out with a great report on this story. Before any wild headlines develop or fear-mongering, keep in mind the number of polio cases we are talking about are six and twenty-one. Six reports of wild polio cases and twenty-one cases of vaccine derived polio have been reported in 2017 so far. To add some perspective, as NPR mentions, when the campaign to eradicate polio began in 1988 there were 350,000 reported cases of polio around the world.
What is “Vaccine Derived” Polio and What is “Wild Polio”?
Wild polio is the polio of old. The regular naturally occurring polio that has existed in this world for centuries. According to the Global Polio Eradication Initiative, possible reports of polio go as far back as 1580 BC. In the 20th century polio became one of the most feared diseases paralyzing 1000 children a day. The massive effort to eradicate polio began in 1988. When the Global Polio Eradication Initiative began that year, polio paralyzed more than 1000 children worldwide every day. The Global Polio Eradication Initiative reports more than 2.5 billion children have been immunized against polio thanks to the cooperation of more than 200 countries and 20 million volunteers, backed by an international investment of more than US$ 11 billion. Some strands of polio have even been eradicated.
What then is vaccine derived polio?
According to NPR’s report vaccine derived polio only comes from the oral vaccine form of polio. In most developed countries like the United States the polio vaccine is injected. The injected form of polio uses a killed polio virus. However, the oral vaccine uses a live but weakened form of the virus. The reasons for using the oral vaccine, as NPR reports, are multiple. One, it’s cheaper. The oral vaccine costs approximately ten cents per dose, whereas the injectable form costs $3 per dose. Plus administering a pill is easier to administer than an injection, especially in places where healthcare is limited. Third, we simply don’t have the manufacturing capacity to produce the killed polio vaccine for every child on this planet. Lastly, those vaccinated with the killed vaccine can still carry polio and spread it to others who aren’t immunized. Thus, making it harder to eradicate the virus.
What’s happening though is the live vaccine in the oral polio is mutating and spreading.
How is vaccine derived polio occurring and spreading?
What researchers have discovered in recent years is that cases of polio are popping up and the virus infecting people is a mutated form of the oral vaccine. The NPR report interviews Raul Andino, a professor of microbiology at University of California – San Francisco. Andino studied how the oral vaccine is mutating. According to Andino, when a child is vaccinated with the live oral vaccine, the virus replicates inside the child’s intestines. From there the vaccine is excreted. In places where there are sanitation issues fecal matter can get into the water allowing the virus to transmit. What Andino also found is that the vaccine grows in strength quickly and only a few mutations are needed for the vaccine polio to turn into a replica of the wild polio. Andino tells NPR,
“We discovered there’s only a few [mutations] that have to happen and they happen rather quickly in the first month or two post-vaccination. As the virus starts circulating in the community, it acquires further mutations that make it basically indistinguishable from the wild-type virus. It’s polio in terms of virulence and in terms of how the virus spreads.”
Where is vaccine derived polio happening?
Yesterdays NPR report says the World Health Organization reported 17 cases of vaccine derived polio in Syria and 4 cases in the Democratic Republic of Congo in 2017. NPR first reported on the mutated polio strains in 2015. In that report they refer to an outbreak in 2000 of 23 cases of polio in Haiti and the Dominican Republic. Doctor Olen Kew studied the genetic code of that viral outbreak. Kew discovered that all of the cases derived from a mutated form of the oral vaccine.
War torn countries like Syria are the most vulnerable to outbreaks. According to the NPR story, the WHO is still investigating about a dozen more cases of potential polio in Syria and the WHO is staging a “massive response to the Syrian outbreak. WHO plans to work with local health officials and aid groups to vaccinate a quarter of a million children in early July. The goal is to reach every child younger than 5 in the area with two doses of two different types of polio vaccine, spaced one to two weeks apart.” Countries like Syria where providing good sanitation systems and access to quality healthcare is a challenge are where the virus has more potential to mutate. In those same areas if there are pockets of unimmunized children the virus has an increased chance of spreading.
The WHO is, according to NPR, ultimately attempting to phase out the live oral polio vaccine, but given war, money, and politics it won’t be an easy task.
For now as Andino tells NPR we have a conundrum. “The very tool you are using for [polio] eradication is causing the problem.”