The mandate, which will go into effect on Dec. 27, requires every employee working at a company with more than one person to have received at least one dose of an approved coronavirus vaccine. Remote workers will not be required to be vaccinated, and there will be no testing option as an alternative.

De Blasio said more information on enforcement and penalties will be available on Dec. 15 and made in conjunction with business leaders. 

The mandate, he said, was a “preemptive strike” to mitigate the rise of the highly contagious Omicron variant of the virus and the spread often associated with holiday get-togethers and cold temperatures that force people indoors. 

Three new cases of the Omicron variant in New York City were announced over the weekend, bringing the total number of cases in the city to seven. 

Nearly 90% of New York City residents currently have at least one dose of the vaccine, and mandates have already been put in place for all city workers and employees and customers of indoor restaurants, bars, gyms, and other entertainment venues. 

The mayor said that many leaders have asked him to implement a blanket vaccination rule to level the playing field with a set standard for all businesses. 

De Blasio insisted that New York City had the legal authority to create such mandates, and that they were far removed from any legal woes President Joe Biden is experiencing with his attempts to create a similar mandate, enforced through the Occupational Safety and Health Administration. 

It is the “legal right of the health commissioner to keep the people of this city safe. That is something that’s been proven time and time again,” de Blasio said at a press conference on Monday morning. “When the health commissioner believes there is a pressing public health threat, he has the ability to act in that situation.”

His corporation counsel, Georgia Pestana, said that right has been upheld in state and city courts over the past few months. 

The mandate will go into effect just four days before de Blasio’s mayoral term ends and Mayor-elect Eric Adams takes over. Adams could easily discontinue the plan on Jan. 1. De Blasio insisted that Adams was well-informed and appeared onboard with the rule changes, but Adams refused to fully confirm. 

“The mayor-elect will evaluate this mandate and other COVID strategies when he is in office and make determinations based on science, efficacy, and the advice of health professionals,” said a spokesperson for Adams in a statement.