And we were: I stopped taking my kids to indoor playgrounds or crowded malls or delicious but densely packed neighborhood Beijing restaurants. Out of an abundance of caution we canceled a family vacation to Cambodia — though my fear was less about catching SARS on the flight than that one of the kids would have a fever from an ear infection upon our return at a border screening, and would be stuck in a prolonged quarantine in China. We instead took a vacation within China, where we carried masks with us but didn’t use them except on a short domestic flight.

In time, during the SARS outbreak, the government shut down theaters and schools in Beijing, as it is doing now in many Chinese cities because these viruses are more easily transmitted in such crowded places.

But there was also a lot of irrational behavior: Entering a village on the way to a hike near the Great Wall, our car was stopped by locals who had set up a roadblock to check the temperature of all passengers. They used an oral thermometer that was only minimally cleaned after each use. What a great way to spread a virus.

The International School of Beijing, where my children were students, was one of the few in the capital — perhaps the only one — that stayed open throughout the SARS outbreak, though the classes were emptier, since so many kids had departed to their home countries. It was a studied but brave move, since a parent at the school had gotten SARS at the very beginning of the outbreak on a flight back from Hong Kong. She recovered fine, but it was close to home and families were scared.

The school instituted a bunch of simple precautionary policies: a stern note to parents reminding them not to send a child to school who was sick and warning them that students would be screened for fevers with ear thermometers at the school door. There was no sharing of food at lunch. The teacher led the kids in frequent hand washing throughout the day at classroom sinks, while singing a prolonged “hand washing song” to ensure they did more than a cursory pass under the faucet with water only.

If a family left Beijing and came back, the child would have to stay at home for an extended period before returning to class to make sure they hadn’t caught SARS elsewhere.

With those precautions in place, I observed something of a public health miracle: Not only did no child get SARS, but it seemed no student was sick with anything at all for months on end. No stomach bugs. No common colds. Attendance was more or less perfect.

The World Health Organization declared the SARS outbreak contained in July 2003. But, oh, that those habits persisted. The best first-line defenses against SARS or the new coronavirus or most any virus at all are the ones that Grandma and common sense taught us, after all.

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