The Trump administration is considering shortening the recommended quarantine time for Covid-19

(CNN) — President Donald Trump’s coronavirus task force is reviewing evidence about how long people need to quarantine to be safe and slow the spread of Covid-19, according to Assistant Secretary for Health Adm. Brett Giroir.

Giroir said at a news conference Tuesday held by the US Department of Health and Human Services that there is starting to be a “preponderance of evidence” that a shorter quarantine, complemented by a test, may be enough to slow the spread of Covid-19, and that a 14-day quarantine may no longer be necessary. He did not say specifically what shorter time period is being considered.

“We are actively working on that type of guidance right now, reviewing the evidence, but we want to make absolutely sure,” Giroir said. “Again, these kinds of recommendations aren’t willy-nilly. They’re worked on with a variety of experts.”

Giroir stressed to CNN’s Wolf Blitzer on “The Situation Room” later Tuesday that the agency has not yet made a decision on the matter but that it “will be driven by data.”

“Half of people become symptomatic by day five. That’s when the virus is present. There’s a long tail of very low probability afterwards. So the postulate is … if you get a test on day seven or day 10, particularly, can that shorten your quarantine from 14 days to perhaps 10 days?” he said.

Giroir added that “people are much more likely to listen to a 10-day quarantine than a 14-day quarantine” so a potentially shorter period “might actually improve our public health responses.”

A CDC spokesperson told CNN, “CDC is always reviewing its guidance and recommendations in the light of new understandings of the virus that causes COVID-19, and will announce such changes when appropriate.”

Health experts have recommended a 14-day quarantine for infected people or individuals exposed to the virus since the early days of the pandemic and the US Centers for Disease Control and Prevention has consistently used that standard during the crisis — recommending early in the pandemic, for example, that people self-quarantine for two weeks after traveling to countries with widespread coronavirus transmission.

Scores of cities and states have also required or recommended two-week quarantines for people traveling from hot spots around the US.

Dr. Peter Hotez, an infectious disease specialist at Baylor College of Medicine, explained to CNN’s Erica Hill on “The Lead” that the 14-day standard intends to cover the potential incubation period of the disease, and that “if you’re going to become symptomatic it’s usually around four to six days.”

“But we know that this is a range, it’s a probability, and roughly about 90% become positive within 10 or 11 days, so possibly that’s what they’re looking at is cutting it short those extra three days because 90% of the people are going to be positive by that period,” he said.

“And even 14 days is not perfect,” Hotez added. “You still get the outliers that are positive after 20 days, so probably something along those lines to ease things up a bit.”

The potential change in guidance would add to a growing list of pandemic-related recommendations that have changed in recent months. In August, the CDC raised the bar on who should get tested, advising that some people without symptoms probably don’t need it — even if they’ve been in close contact with an infected person — before once again changing that guidance the following month.