WATCH: Brianna Keilar grills union leader over claims of being 'pro-vaccine but anti-mandate'

One of the leaders of a New York City union resisting vaccine mandates was grilled about the stance during a Tuesday appearance on CNN.

"Hundreds of New York City firefighters are calling in sick this week as a covid vaccine mandate for city employees goes into effect," CNN's Brianna Keilar reported.

She played a clip of New York City Mayor Bill de Blasio.

"The folks who are out sick and really aren't sick, the folks who are faking it, are doing immense disservice to the people of this city and to their fellow members in service," de Blasio said.

To find out why New York firefighters are resisting the free, safe, and effective vaccines, Keilar interviewed Jim McCarthy of the Uniformed Fire Officers Association.

"A sickout, estimated at 2,300. Isn't that irresponsible for firefighters to do that?" Keilar asked.

"Well, I don't agree with the mayor and his description of what is going on," McCarthy replied.

"There has been resistance among your union membership to the vaccine mandate for city employees. Tell us why you're fighting the mandate," Keilar said.

"Well, first of all, we're pro-vaccine, we're just anti-mandate," McCarthy claimed. "If people decide they want to have a religious exemption or reasonable accommodation or a medical exemption, you have to apply for that and get affidavits to support that."

"Okay, a few things there I want to talk to you about. You said you are pro-vaccine but anti-mandate. I mean, isn't that just like someone saying they are pro-condom but they're anti someone telling them they have to wear one," she asked.

"You see the issue here right? The prophylactic, whatever it is, isn't just about the person who uses it, it's about the people around them who could be affected by them and firefighters are forward-facing people who are dealing with a vulnerable population," Keilar said.

"Yes, they are forward-facing, and we have been involved in this pandemic from the very beginning," he replied.

"Address what I'm asking you here," Keilar said.

"I'm going to, yeah," he replied.

"The problem of being pro-vaccine and anti-mandate," she said.

"Well, we have -- again, we've been exposed to the virus very early on. Many of our members got sick, and they have a high --" he replied.

"It's not the same. Just today, the CDC is pointing to research that shows there is more consistent immunity when it comes to the vaccine than infection," Keilar noted. "That's not something you can hang your hat on."

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