In one of the greatest medical successes of the century, the polio virus – which once crippled, paralyzed, or even killed hundreds of people every year – has been eradicated in the United States since 1979, thanks to successful vaccination practices. Because it hasn’t been seen here in a couple of generations, some people may believe that vaccinating against it is no longer necessary – but polio still exists in several other countries, so vaccines are needed both here and in those places in order to stop the spread of the disease.
Polio hasn’t been reported in the Western hemisphere since 1991 in Peru, but it’s still an unfortunately common occurrence in Africa, Asia, and the Indian subcontinent. As long as the virus that causes the disease still exists, anyone who has not received a vaccination against it is susceptible to contracting it; in an increasingly small world of globalization, it puts even currently polio-free nations at risk. This means that an unvaccinated American child who is exposed to the virus while traveling through or living in a country where it is present could contract polio. Unvaccinated children aren’t the only ones at risk: even adults who had polio as children should be vaccinated before traveling to a country with polio, because the strain they contracted in the past may not immunize them against current strains.
Because polio often doesn’t show visible symptoms for long periods – sometimes years – an unvaccinated person who picks up the virus abroad could easily bring it back to a Western country where it’s been eradicated and spread it to others without knowing. The more unvaccinated people there are, the more likely it is to spread, and it could quickly and easily cause an epidemic return of the disease.
A set of polio vaccinations are now standard practice for children beginning at two months and finishing between four and six years of age. It’s important that this remain standard to prevent the return of polio in the Western hemisphere.