Peanut butter and Swiss cheese: A Back to School metaphor

As the school year gets into full swing, students and teachers across our area are wearing masks and keeping socially distant in class, to prevent the spread of coronavirus. They're also taking steps to protect kids who have severe allergies from getting exposed to the peanuts or other foods that could trigger a life-threatening reaction.

In both cases, it takes multiple measures to reduce risk.

You might think of it as the Swiss cheese approach, with each measure represented by a slice of cheese.

No one measure is perfect enough by itself to keep the virus or the peanuts from getting through - that's the holes in the cheese. But as we add more protective measures, the chances that those holes will line up — and that the virus or the allergy-triggering food will get through — goes down.

Here's a video I made that shows this concept:

This concept has been used in hospitals for decades to help describe the steps doctors, nurses and others take to protect patients from infections or surgical accidents.

During the pandemic, Australian virus expert Ian MacKay has taken it to a new level with graphics that he produced and translated into many languages, and made available for free.

Each layer of protection involves someone making a decision to do what they can to protect others. This community-minded spirit has driven efforts by parents across the state to press for mask requirements, timely case notifications and clear quarantine guidance from their district and county authorities.

The result? A growing number of districts where masks are required for all inside K-12 schools, or for those in lower grades only. This map, crowdsourced with information from people across the state, shows the current status as of September 18. Green and yellow pins represent schools with mask requirements, blue pins represent those that are only "recommending" mask use. To see an interactive version visit https://bit.ly/MImaskmap .

A grassroots group of parents across the state is working to build support for a statewide mask requirement in K-12 schools that would help protect kids in the "blue pin" districts. Called the Michigan Parent Alliance for Safe Schools, it has launched a petition and Facebook page to share information and help parents in "blue pin" districts come together to press for local policies.

Of course, the actions taken by students and staff inside schools can only do so much. As COVID-19 cases rise in our state and nation, the same concept of "layers of protection" should apply in our everyday lives.

Vaccination of people over age 12, wearing masks in indoor public places and crowds, avoiding massive gatherings if you are unvaccinated or immunocompromised, encouraging good ventilation in buildings, getting tested if you've been near someone who just found out they have COVID-19, staying home if you feel sick or test positive, and meeting up with people outdoors are all simple steps we can take.

Because children under 12 can't yet get vaccinated, they need the rest of us to protect them with layers of safety and keep the virus from getting to them. That includes making sure that everyone who lives with or interacts with them and is old enough to get vaccinated does, and also keeping them from being around people who have COVID-19 symptoms.

And because every serious case of COVID-19 takes up health care resources that could otherwise be used to care for someone with another health problem, layering on the preventive measures helps all of us.

If you had a heart attack, or a car accident, or a bad fall today, your care might suffer because the emergency medical teams are busy caring for COVID-19 patients who caught the virus because it slipped through the holes in the Swiss cheese.

So if you haven't yet, please think about what kind of layers you can add in your own life, to protect others and yourself.