"Don't let this be you," Sesma told her. "If you truly love your loved ones, don't let this be you. Continue to take all the precautions. Take extra precautions. Exaggerate if you have to."
The powerful interview had taken its toll by the time Sidner went live.
"To see the way that these families have to live after this and the heartache that goes so far and so wide, it's really hard to take," she told anchor Alisyn Camerota before trying to apologise through tears.
"No apology needed," Camerota told her. "We've been watching your reporting on the ground. Throughout this horrific year, and we have all been struck by the grief.
"Sara, we all appreciate the heart that you bring to this every single day as well as your excellent reporting."
Sidner responded: "It's just not OK. It's not OK what we're doing to each other. These families should not be going through this. No family should be going through this."
On Twitter, Sidner wrote that it was "not my proudest moment as a reporter" but that she "could not hold this back".
The United States continues its losing fight against a virus that has infected more than 90 million people worldwide and killed almost two million.
The US is the worst affected with more than 376,000 deaths, followed by Brazil with 203,000 and India with 151,000.
