With more states considering vaccine requirements for public employees, the president of the AFL-CIO was asked Tuesday whether the labor federation supports vaccine mandates in the workplace.

“Yes, we do,” Richard Trumka said on C-SPAN, responding to a question from a viewer. “If you’re coming back into the workplace, you have to know what’s around you.”

The remarks from Trumka come at a time when the COVID-19 delta variant is spreading rapidly among the unvaccinated, prompting officials to weigh mandates for workers in order to boost vaccination rates and protect public health.

New York Mayor Bill de Blasio announced Monday that the city’s municipal workforce would have to be vaccinated or undergo weekly testing. California Gov. Gavin Newsom said the same day that his state’s employees and health care workers would face a similar requirement.

The mandates have drawn resistance as well as support from different unions that represent public employees and health care workers.

A union representing New York City paramedics and EMTs, FDNY EMS Local 2507, declared its opposition to de Blasio’s mandate, saying that “the city and the mayor cannot simply disregard the civil liberties of the workforce.” The union said any such requirement should be subject to bargaining.

But a spokesperson for the United Federation of Teachers, which represents most public school teachers in New York City, told The Wall Street Journal that de Blasio’s requirement “puts the emphasis on vaccination but still allows for personal choice and provides additional safeguards through regular testing.”

In California, a union representing 300,000 health care workers voiced words of support for the state’s mandate. According to Politico, SEIU-UHW called it “a reasonable step to protect the safety and wellbeing of patients and healthcare workers.”

Last week, however, hospital workers with 1199 SEIU in New York held a rally against a vaccine requirement implemented by New York-Presbyterian Hospital. “Force is not the answer, and a mandate forcing people at the barrel of a gun is not right,” one protesting worker told NY1.

Unions have a responsibility to represent their members, and union members are no different from the general U.S. population: a significant share are not vaccinated. But Trumka said Tuesday that vaccine requirements would help protect everyone at a time when COVID-19 caseloads are increasing once again.

“If you come back and you’re not vaccinated, everybody in that workplace is jeopardized,” Trumka said. “[And] if we don’t know if you’re vaccinated or not, we can’t make the proper accommodations to make sure that you are protected and everybody else is protected.”