Michael Solomonov and Marc Vetri, arguably Philadelphia’s most famous hometown chefs, have joined the list of restaurateurs calling for indoor patrons to be vaccinated.

This new movement — in the name of keeping restaurant staffs and fellow diners healthy as the coronavirus continues to spread — has drawn mixed reactions.

Solomonov and his business partner, Steve Cook, posted on their reservation systems that Zahav in Society Hill, Abe Fisher in Center City, and Laser Wolf in Kensington will start requiring proof of vaccination on Aug. 31 for indoor dining. Their restaurants K’Far, Goldie, Dizengoff, and Federal Donuts are not following the policy, and a company spokesperson declined to elaborate.

Vetri and business partner Jeff Benjamin said that for reservations beginning Sept. 7 at Center City’s Vetri Cucina and indoors at South Philadelphia’s Fiorella Pasta Bar, people will be asked if they are vaccinated or have recovered from COVID-19. “We’re not carding people,” Vetri said Monday.

“In light of the current state of the unfortunate growing number of Covid cases, we are amending the reservation policy at Vetri Cucina and Fiorella in Philly,” a message on Fiorella’s Instagram began.

“Due to the physical layout and tight space indoor at Fiorella, the reconvening of our pasta classes and special events at Vetri Cucina that encourage guests to interact with each other, we will require all indoor diners at both restaurants to be either vaccinated or have recovered from Covid-19. Our coworkers are already 100% vaccinated since March. … While we understand and appreciate that vaccinations are a personal choice, this is simply a policy based on current scientific guidance in the hopes that we can do our part to help reduce transmission and avoid further shutdowns. No one wants to go back to that! Should you, for whatever reason, choose not to get a vaccination, you can still feel free to avail yourselves of our outdoor dining at Fiorella … which is most of the seating there. We expect that, much like last year, guidance will continue to change and as it does we will update our policies continuing to provide a safe and comfortable environment for both our team and our guests.”

Vetri was outspoken in summer 2020 against the city’s lockdown of restaurants, criticizing Mayor Jim Kenney in an Inquirer op-ed for not providing a plan that “listens to public health experts as well as economic experts to safely balance our city’s broader well-being.”

He added: “At some point we have to figure out how to live with COVID in the most responsible way.”

Last week, Cornerstone in Wayne, Martha in Kensington, and Irwin’s, in South Philadelphia, became the first Philadelphia-area restaurants to call publicly for proof of vaccinations. Some other restaurants are still deliberating. Such policies require all staff members to be vaccinated; many workers are, but some are not.

» READ MORE: Updated: The Inquirer's list of Philadelphia-area restaurants that require vaccinations

Danny Meyer, the high-profile restaurateur who heads Union Square Hospitality Group in New York and Washington, announced that all USHG employees must be fully vaccinated, effective Sept. 7. “If you really want to go unvaccinated, you can dine somewhere else, and you can also go work somewhere else,” Meyer told CNN. “I would call this a company policy rather than a mandate.”

The beleaguered restaurant industry had believed that business was on the way back, at long last, in May and June 2021. But the recent spread of the coronavirus’ highly contagious delta variant has worried some restaurant workers and steered more patrons to dine outside.

» READ MORE: Owners of Le Virtu explain why they're insisting upon vaccination proof for indoor dining

In an op-ed posted Monday at Inquirer.com, Francis Cretarola, who owns the South Philadelphia restaurant Le Virtu with his wife, Cathy Lee, explained his restaurant’s proof-of-vaccination policy and his reaction to naysayers.

Those who “for political reasons or due to mistrust of science-based reasons refuse vaccination and insist that indoor dining is an essential freedom,” he wrote, “they can certainly dine elsewhere. We trust in the science and those who’ve dedicated their lives to the study and prevention of contagious diseases. And we refuse to indulge comparisons of our requests to the policies of Nazi Germany — such comparisons and others have been made on both our and our like-minded fellow restaurant owners’ social media. To compare not being able to dine inside to the imprisonment, torture, and murder of millions based on their religion, ethnicity, sexuality and sexual identity, political beliefs, and perceived genetic imperfections is ignorant and offensive on its face.”

Meanwhile, Philadelphia’s health department has said it had no plans to mandate proof of vaccinations. New York City Mayor Bill Di Blasio announced last week that the city would require vaccination proof for indoor customers at restaurants, bars, and gyms.