Elliot Rosenberg is a retired New York City public school teacher.

At 82, I’m a potential covid-19 statistic. But not quite there yet. After the initial blast of data showing mortality by demographic class, my age group took “sheltering” during the pandemic seriously. Yet stepping out into the world, and into danger, is inevitable.

I look out my apartment window at a park in Lower Manhattan, seeing young people cavorting, seemingly without a thought for coronavirus or infection rates, and the lively scene stirs only a sense of dread.

For many of us born midcentury, it’s a case of double jeopardy. Seven decades ago, when my peers and I were young, we fell in the bullseye of another terrifying viral menace, one generally bypassing folks now our current age — an inversion of the covid-19 threat. Its very name highlighted our vulnerability: infantile paralysis. Also known as polio.

Before 1955, microbiologist Jonas Salk’s work was known only to his colleagues. Almost overnight, he emerged as a household name for solving the mystery of how to conquer the virus.

Older Americans remember how polio struck viciously each summer of their youth. Newsreels at movie houses across the land showed children trapped in huge metal cylinders, “tank ventilators” known as iron lungs. Covering your eyes couldn’t drown out the ominous grinding of the contraption’s motor. Between double features, the house lights went on and ushers moved up and down the aisles, jingling coins in canisters, collecting donations.

Annual March of Dimes campaigns sought funds to battle a viral invader that crippled more often than it killed. Widely circulated stamps depicted a tiny victim trying to rise from her wheelchair. We all knew that polio had put Franklin D. Roosevelt in a wheelchair, hitting him at age 39 — you weren’t even protected if you made it safely out of childhood.

The 1946 Hollywood productionSister Kenny” offered tribute to an Australian nurse whose physical therapy technique helped some patients. But a cure? No. Nor could the therapy aid against the worst strain of the disease, the kind that landed you in the dreaded metal cylinder.

How the virus passed from victim to victim was more puzzling than covid-19 transmission today. Some regarded water as suspect, so, in New York, we steered clear of Coney Island and beachfronts elsewhere, and swimming pools. Many people avoided crowds of any sort, as with the coronavirus.

Well-off parents could send their vulnerable children to presumably safer countryside camps distant from polluted coastlines and congested cities. Less-affluent folks gave their offspring the common-sense advice about good hygiene that sounded a lot like the constant reminders issued today.

My father’s evening newspaper, the New York World-Telegram, gave a front-page box score of new cases of infection reported weekly, borough by borough. Nationwide, in 1952 a record 57,628 cases were reported. Three more unsettling years would pass before Salk’s discovery would end this nemesis and relieve my generation of our first jeopardy.

Now, decades later, comes our second — even more dangerous because it’s more widespread, and deadlier. Staying homebound and safe must cease when long-delayed medical appointments can no long be put off and we must venture to doctors’ offices, clinics or hospitals.

We will wear our imperfect masks, sharing the same sidewalks, crosswalks, mass transit, building lobbies and elevators with our juniors. Mature, considerate people will follow government guidelines for reducing risks to themselves and to total strangers.

But consider one of those carefree youngsters I see in the park. If he ignores his social responsibility under quasi-compulsion, how will he respond after months of relaxed rules and then the “second wave” of infection — regarded as inevitable by many experts — races across the land?

Is he his brother’s keeper? No. But his grandma’s and grandpa’s? You bet.

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