PLYMOUTH, N.H. (CBS) — Families need to plan ahead to ensure a safe Thanksgiving gathering during the coronavirus pandemic, Dr. Deborah Birx of the White House Coronavirus Task Force said Monday. The doctor spoke with reporters after visiting Plymouth State University in New Hampshire.

She urged the public to continue social distancing, wearing masks and “really [ensure] that when in private, we’re taking the same precautions that we take in public.”

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“We will have to adapt this Thanksgiving, just like the students have adapted to how they interact with each other,” Birx said.

Families need to remain vigilant to protect vulnerable members, she warned. “This virus can spread among families and among friends if you take your mask off and are primarily indoors.”

“I’m very careful to say physically distanced and socially engaged,” Birx said. “Maybe it means…provide a safe space that’s physically distanced from others where people can interact with [vulnerable individuals] inside the house with masks on. When you’re eating and happen to have your mask off, you maintain greater physical distance between those that are most vulnerable.”

Birx said there is evidence of “silent spread” of coronavirus in the northeast.

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While she sees people wearing masks and being socially distanced in public, Birx said, “we also need to bring that same attention to detail into our homes and ensure that we’re not bringing small gatherings together, un-masked, in houses, where there could be spreading events among those individuals that are silent spreaders because they don’t know they’re infected.”

According to the doctor, most people under 35 who have coronavirus will be asymptomatic.

“In many situations, test positivity going up by 0.1, 0.2 when you’re this low is an indicator that there’s progressive spread in addition to the case numbers,” Birx said.

Massachusetts has seen a recent uptick in coronavirus cases. Forty communities are considered at “high risk” for coronavirus in the state.

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“We know that [holidays] become transmission events and so we have to be careful both in public and in private.”