Polio isn’t a serious threat to most children. We still require vaccines for it anyway.

Salk’s original polio vaccine used an inactivated virus. Given imperfections in the inactivation process, it would occasionally cause polio itself. Vaccines for covid-19 are different; they don’t use the coronavirus, so it is physically impossible to get the disease from the shot. In that way, coronavirus vaccines are far safer. And the coronavirus vaccines have been rapidly given to more than 4 billion people around the world, including to tens of millions of children, with a safety profile that far exceeds those of the original polio vaccine. In fact, it is greater than any vaccine in our nation’s history.

The comparison has other limits, of course. Polio was a devastating disease that in the 1950s caused as many as 3,000 deaths annually. There was no capacity to do screening testing — kids were tested for polio only after they showed symptoms and were likely already on the way to serious illness. It would be like waiting to test our children for covid-19 until the virus had already led to hospitalization.

Mercifully, covid-19 has led to only about 700 deaths among children in the United States, a tiny proportion of the overall death toll. Nonetheless, it has closed schools and canceled major public gatherings. And as with polio, thousands of children have been hospitalized with severe illness, and thousands have developed multisystem inflammatory syndrome, a life-threatening condition. Meanwhile, the number of infected children who suffer from long covid is unknown, as is their prognosis.

There’s another difference between polio and covid-19: We eradicated polio, but given the highly infectious nature of the coronavirus, it will become endemic in the United States.