The news that President Trump and his wife tested positive for the coronavirus has caused concern for both him and all those he came into contact with recently.

Many, including former Vice President Joe Biden, Senator Kamala Harris, and the president’s children Ivanka and Barron, have tested negative. However, Dr. Jennifer Haythe, a critical care cardiologist, said they are not necessarily out of the woods.

“Even if you test negative today, you still could become positive,” she told NY1’s Roma Torre.

The incubation ranges from 2 to 14 days, and tests can come back negative until there is a large enough amount of the virus to be detected.

This can be seen in the case of White House aide Hope Hicks, who initially tested negative before testing positive. Dr. Haythe also noted it could have been a false negative. She said all those who were in contact with President Trump or Hicks must continue to quarantine and be tested.

As for President Trump’s prognosis, Dr. Haythe acknowledged that he could be at increased risk due to his weight. “But in general, probably his biggest risk factor at this point is age,” she said. “However, [the] overwhelming number of people who get COVID are going to be OK.”

It is currently unknown exactly when the president was infected, and who he contracted the virus from. Dr. Haythe said a large amount of contact tracing will be necessary to pinpoint when the initial infection occurred. Already, the president of the University of Notre Dame and Utah Senator Mike Lee, who were in attendance at last Saturday’s announcement of the president’s Supreme Court nominee, have both tested positive.

Trump must now quarantine for at least 10 days, ending 24 hours after his last fever or when he begins testing negative. Dr. Haythe said he should be in isolation, having no contact with anyone except medical personnel in sufficient PPE.