Los Angeles and St. Louis both reinstated mask mandates. Photo: Nina Westervelt/Bloomberg via Getty Images

Last week, Atlanta restaurateur Armando Celentano posted a sign on his restaurant, Argosy: “No Vax No Service,” after identifying breakthrough COVID-19 cases among his vaccinated staff. Celentano explained his decision to the Atlanta Journal-Constitution, saying, “I have to do what I think is right to protect the people who rely on me to make a living.” In doing so, he joined a growing wave of business operators who are taking a hard line against unvaccinated customers. Even without mandates, a growing body of evidence suggests those unvaxxed customers should avoid bars and restaurants no matter what.

COVID cases continue to rise sharply around the country, with the New York Times reporting a 144 percent upsurge over the last two weeks. Hospitalizations and cases have not increased as much, however. This increase in cases has led cities like Los Angeles and St. Louis to reinstate mask mandates, and Argosy is one of an increasing number of restaurants requiring proof of vaccination. (And today, per the Times, the CDC is expected to recommend “that people vaccinated for the coronavirus resume wearing masks indoors in certain areas of the country.”) One CNN contributor, Dr. Jonathan Reiner of George Washington University, has gone so far as to say that the unvaccinated “should probably not eat at a restaurant” because they “are at great risk of becoming infected.”

I emailed Dr. Purvi Parikh, an allergist and immunologist at NYU Langone Health, to ask about this. She replied, “Unvaccinated people should be very worried” about their health when going into restaurants. “I would be more cautious if you live in an area where vaccination rates are low or if you are a high-risk individual especially with indoor dining,” she added.

Restaurant dining rooms, after all, remain uniquely suited to spreading coronavirus: They are often poorly ventilated, crowded spaces where numerous strangers interact, ideal circumstances for viral spread among unvaccinated customers. Where capacity and social-distancing restrictions have been lifted, safety measures simply can’t be guaranteed. The spread of the Delta variant, which is responsible for 80 percent of infections in the U.S., can reportedly be transmitted in only five to ten seconds, according to Australian health officials, the San Francisco Chronicle reports, which is much, much quicker than the original coronavirus strain. According to one study, Delta is more contagious because there’s simply more of it in infected people, to the tune of 1,000 times more copies of the virus than the original strain. While breakthrough cases can happen, they are often not severe, while nearly all of COVID deaths in recent months have been among the unvaccinated — and according to the CDC, 97 percent of hospitalizations are among the unvaccinated as well.

Yet as vaccination efforts have plateaued — the number of daily doses has declined, the Times reports, from a peak of 3.3 million in April to just 537,000 — government officials have started to enforce vaccine requirements. Yesterday, the Department of Veterans Affairs became the first federal agency to require vaccination, and a group of major medical organizations has called for mandatory vaccination of health-care workers. On Friday, New York City mayor Bill de Blasio urged employers to require vaccination, and yesterday announced that government employees will have to get vaccinated or endure weekly COVID tests. California governor Gavin Newsom also says his state will require government workers and health-care workers to be vaccinated.

Florida, meanwhile, has taken the exact opposite approach: In May, Governor Ron DeSantis signed legislation banning vaccine passports, and is selling merchandise mocking masks. The state now accounts for roughly a quarter of new infections, and DeSantis is asking Floridians to get vaccinated.

Dr. Parikh supports the vaccine requirement — which has been made policy in countries including Italy — being instituted by some businesses. “Requiring vaccine cards will likely be the next best thing to ensure safety,” she explains.