Polio Vaccination Gone Wrong
The story of worldwide Polio eradication is very close to becoming one of humanity's greatest victories. Polio has been almost completely eradicated the same way that smallpox has been eradicated. The exception is small pockets of Africa where there are outbreaks of polio where Nigerian Muslims aren't getting vaccinated because they hold to of crazy conspiracy theories which say that the oral polio vaccine causes AIDS, sterility, or that it causes polio itself.
The Oral Polio Vaccine (OPV) works better than the Inactivated Polio Vaccine (IPV) but the increased efficacy comes at a higher risk of "reversion". There's a 1-in-1.5 to 3 million chance (depending on the population) that OPV will infect a child with polio. In a population where everyone gets vaccinated this wouldn't be a major problem - 1 out of 3 million children gets polio and the rest get lifetime immunity, which is much better odds than sitting back and hoping you don't contract it naturally. But superstitious populations that aren't getting vaccinated don't have herd immunity, and the one unlucky kid spreads his disease to the unvaccinated population. And that's exactly what happened in Nigeria earlier this month. There are three strains of polio "in the wild" but the strain used in the vaccine is distinctive, and that's the strain causing the latest outbreak. One unlucky kid out of ~2 million caught the disease and because the population has been incompletely vaccinated there are dozens of new "vaccine-only" polio cases. "The vaccine gives you polio" became a self-fulfilling prophecy.
I'm wondering what it's going to be like to be a WHO worker now. It's hard enough for me to explain to a literate, rational, science-friendly audience that even though the vaccine caused an outbreak of polio the answer is more polio vaccine - I'd hate to try to convey this concept to a superstitious Nigerian across religious, ethnic, and cultural barriers.
The Oral Polio Vaccine (OPV) works better than the Inactivated Polio Vaccine (IPV) but the increased efficacy comes at a higher risk of "reversion". There's a 1-in-1.5 to 3 million chance (depending on the population) that OPV will infect a child with polio. In a population where everyone gets vaccinated this wouldn't be a major problem - 1 out of 3 million children gets polio and the rest get lifetime immunity, which is much better odds than sitting back and hoping you don't contract it naturally. But superstitious populations that aren't getting vaccinated don't have herd immunity, and the one unlucky kid spreads his disease to the unvaccinated population. And that's exactly what happened in Nigeria earlier this month. There are three strains of polio "in the wild" but the strain used in the vaccine is distinctive, and that's the strain causing the latest outbreak. One unlucky kid out of ~2 million caught the disease and because the population has been incompletely vaccinated there are dozens of new "vaccine-only" polio cases. "The vaccine gives you polio" became a self-fulfilling prophecy.
I'm wondering what it's going to be like to be a WHO worker now. It's hard enough for me to explain to a literate, rational, science-friendly audience that even though the vaccine caused an outbreak of polio the answer is more polio vaccine - I'd hate to try to convey this concept to a superstitious Nigerian across religious, ethnic, and cultural barriers.