In July 2022, an unvaccinated man in New York had been sickened with variant poliovirus genetically linked to the spread in London. We can stop it. Help eradicate polio by making a donation in honor of World Polio Day, October 24. Your contribution will be tripled by the Bill & Melinda Gates Foundation. Join the Rotary Club of Salem Creekside as we help stop the spread in the US and around the world.
For much of the developed world, polio is a distant memory. Long gone are the days of terror in the 1940’s and 50’s with children going to bed with a mild case of flu only to wake up rubber-limbed and burning with fever. Thousands were paralyzed. Some ended up in the dreaded iron lung device which helped them breathe.
In 1988 wild poliovirus paralyzed hundreds of children every day, with an estimated 350,000 polio cases across more than 125 countries that year. Since then, cases have plummeted 99.9%. From January to early August of this year 14 cases of wild polio were confirmed in Pakistan and one in Afghanistan. Four additional cases were reported in Mozambique in an outbreak that began in Malawi in late 2021 and was linked to a virus strain that had circulated in Pakistan.
A vaccine developed in the early 1950s by virologist Jonas Salk using killed virus, known as the inactivated polio vaccine or IPV carries no risk of seeding vaccine-derived or variant, outbreaks, because the killed virus cannot mutate. This is injected and hit only protects the vaccinated individual and cannot prevent person-to-person spread, which is required in an eradication program.
The oral polio vaccine, or OPV was developed in the late 1950s by physician Albert Sabin. And became the vaccine of choice for polio eradication because it’s safe, inexpensive, and easy to administer and the live but weakened vaccine virus replicates in the gut and produces strong intestinal immunity., which can be shed in their stool for several weeks. In areas with poor sanitation, the weakened virus spreads, stimulation an immune response in the unvaccinated. In 2000 children started getting sick in the Dominican Republic and Haiti. From July 2000 to July 2001, 21 children were paralyzed on the island. This however was a weakened vaccine virus that became virulent. All but one of the children were unvaccinated or incompletely vaccinated, and from countries where vaccination rates are as low as 7 %. Some 3.2 million children were vaccinated on the island and the outbreak stopped. In 2016, type 2 stain was removed from oral vaccine formulas to avoid the risk of seeding new vaccine variant outbreaks The number of children paralyzed by the type 2 variant poliovirus surged from 2 in 2016 to more than 1,000 in 2020, spread over 2 dozen countries, most of them in Africa, made worse by the halt to immunization during the COVID-19 pandemic that left 80 million children unprotected. Variant cases now vastly outnumber cases of wild polio.
Recently variant poliovirus outbreaks have emerged over the past two decades as a significant stumbling block in the effort by Rotary and its partner in the Global Polio Eradication Initiative to wipe out the disease. The outbreaks are different from those driven by wild poliovirus, which circulated naturally in the environment for millennia and remains endemic in just two countries, Afghanistan and Pakistan. But the outcome is the same—the virus in either kind of outbreak can, in rare instances, cause paralysis. In 2011 staff at the Bill and Melinda Gates Foundation, wondered if the live virus in the traditional oral vaccine could be tweaked to limit its ability to mutate.
From May to August in 2017 a trial was conducted on a new variant NOPV2 and was first used in November of 2020., then rolled out in March of 2021 in Nigeria and Liberia. Through the first half of 2022, more than 370 million doses were administered in more than 20 counties. It’s looking like it’s doing what it is supposed to do: induce population immunity and interrupt transmission in most settings. It won’t stop transmission if immunization campaigns cannot reach close to 90% of children in the response zones. Adding to the challenge in Africa, a drop in routine childhood immunizations during COVID-19 led to surges in cases of measles, yellow fever, cholera, and other infectious diseases. Recently officials detected polio in London and New York City sewage this year.
We’ve never been closer than we are now. The Taliban leadership that returned to power in Afghanistan a year ago agreed to allow house-to-house immunization campaigns to resume nationwide after a 3 ½ year ban in so. And there are more scientific innovations in t, including more genetically stable versions of the oral vaccines for the other two types of polio, modeled on nOPV2.
Rotary Magazine, October 2022