Can a polio vaccine give you polio?
One decade after the introduction of vaccine, the average yearly paralytic polio cases in the U.S. dropped from 15,000 to 100. Data from CDC. Drawn by Diana Pi
The tip of an iceberg
In July, hell broke loose with the discovery of one locally acquired case of paralytic polio in a 25-year-old healthy but unvaccinated man in New York. So how can a single case of polio roil the public health sector – similar to or worse than 22,000 cases of monkeypox?
Background story
With an aggressive vaccine program, the U.S. eliminated polio in 1979. (Yup, I drew the graph.)
Most people who are infected have no symptoms. Some suffer a few days of stomach flu-like illness. Only 1 in 200 to 2,000 develops paralysis. Experts estimate that for each case of paralysis, hundreds to thousands have been infected and just don’t know.
For example, albino tigers are rare, occurring 1 in 10,000 births in the wild. To spot a white tiger in the wild, you can safely bet there are over 9,000 orange ones running around somewhere.
A confirmation is wastewater testing. Polio virus has been detected in wastewater samples not only in Rockland County, where the first known victim resides, but also in neighboring Orange County, Sullivan County, New York City, and Long Island. The first positive sample dates to April.
The culprit: a polio vaccine?
Before you cancel your trip to NYC, or I-told-you-so tongue-lash me for my unwavering vaccine-worship, allow me to get one point across.
About the polio vaccines
We have two different kinds. One is a dead virus. Given as a shot, it provides 99% lasting protection against the worst outcome of polio – paralysis. It’s the only vaccine we’ve used in the U.S. since 2000.
The second one is a live-attenuated virus. Like a biter with no teeth, it cannot give us polio. Given orally as drops, it replicates in the guts. In one to two months, our guts develop a robust anti-polio immune system and rids the virus completely.
How does a vaccine that protects you from polio give you polio?
The live vaccine has many advantages over the dead one, which I won’t dwell on. But it’s a saint with a small devil detail.
Rarely, rarely, as in 1 in 10 million vaccinations, the harmless vaccine virus can mutate to a virulent form – and cause polio in an unvaccinated or inadequately vaccinated person. But that’s not the only problem. An outbreak needs a critical mass of vulnerable (unvaccinated) population to sustain the transmission. These are communities that are way behind in vaccinations.
Can Cleveland be the next Rockland?
Not today. For a highly contagious disease like polio, a 90% vaccination rate is adequate to protect our community. In Cleveland, our vaccination rate is 89%. In comparison, the rate in Rockland County and surrounding areas is 60%.
Here’s the big picture. It won’t be long before polio will be eliminated, like smallpox. I can see the finish line. The vaccines are that good. But so long as there’s one case of polio, nobody is safe. This crisis only reinforces my one message: Get vaccinated.