Two co-hosts of The View, Ana Navarro and Sunny Hostin, were abruptly pulled from the set on live television on Friday morning after testing positive for the coronavirus, minutes ahead of a live in-studio interview with Vice President Kamala Harris.

Joy Behar, another co-host of the show, announced that they had contracted breakthrough cases. None of the hosts were wearing masks on set, but members of the live studio audience were all masked.

“Ana and Sunny, at the last minute, we realized they tested positive for Covid,” Ms. Behar said. She said Ms. Harris, who was in the building preparing to come onstage, was going to appear remotely on the program from another room.

After the positive cases were announced, Ms. Behar and another co-host, Sara Haines, were the only hosts left on set (Whoopi Goldberg, another host, was off on Friday). They took questions from the audience to fill the program while the Secret Service tried to find a way for Ms. Harris to safely participate in the planned interview.

The announcement came minutes after the hosts had been discussing the importance of getting vaccinated and after they had promoted Ms. Harris’ appearance as her first “in-studio” interview since taking office.

Ms. Harris’ appearance on “The View” had long been planned and was one of only a handful of television interviews she has participated in since taking office. The timing was not ideal for a vice president whose portfolio includes immigration issues, but who had hoped to use the opportunity to talk about issues such as broadband access and women in the work force.

It came as the administration’s handling of Haitian migrants at the border prompted outrage among Democrats and called into question President Biden’s decision to swiftly deport thousands who had been arriving en masse at a small Texas border town.