Indoor eating and drinking establishments have been on the leading edge of the response to the COVID-19 pandemic.

They were some of the first businesses to be closed by government order, and among the last to be allowed to reopen – with new rules regarding mask-wearing and social distancing that limited their ability to serve their customers.

Three Portland restaurants have taken the next step – this time, without waiting for a government mandate. Little Giant on Danforth Street, Portland Hunt & Alpine Club on Market Street and Crown Jewel on Great Diamond Island have announced that they will serve only people who have been vaccinated against COVID 19.

They are among the first businesses to come to this decision, but they certainly will not be the last. At a time when cases are rising across the country, it makes a lot of sense.

Others are making the same choice. New York City will require proof of vaccination at all indoor restaurants, bars and gyms. Elsewhere businesses are taking the lead.

Large employers here in Maine, including the state’s two biggest health care systems, MaineHealth and Northern Light, will require all of their employees to be vaccinated.

Concert venues, movie theaters, retail stores and other businesses that invite the public inside are also going to have to decide how they plan to keep customers and employees safe.

The challenge for all of them will be verifying who among their potential customers has received their shots. Our overly complex and decentralized heath care system cannot spit out vaccine “passports” like those produced in European countries, so it will probably be up to private businesses to develop a secure, easy-to-use credential that can be universally accepted.

That will make it easier for other restaurants and bars to follow the example of Little Giant, Portland Hunt & Alpine and Crown Jewel.

The Pfizer, Moderna and Johnson & Johnson vaccines are highly effective, even against the very transmissible delta variant. No vaccine is perfect, but breakthrough cases involving vaccinated people are not what is overwhelming hospitals in other states. The bulk of the new cases involve unvaccinated people, who get much sicker when they get infected.

If access to entertainment venues provides an incentive for people to get vaccinated, that would be good for their health and their community’s.

But businesses like the three Portland restaurants are rightfully looking at a narrower question: How can they best take care of the health of their customers and staff?

Mixing with unvaccinated people indoors is not safe. Restaurants may be the first to draw this line, but by now we should be used to them being on the leading edge.