LONE TREE, Colo. (KDVR) – As the omicron variant surges, the demand for COVID-19 tests is high. Many people are also seeking tests as they return from Christmas gatherings and travel, and perhaps prepare to see more people for New Year’s.

However, it may be too soon to tell who was exposed or infected during Christmas celebrations.

Centers for Disease Control and Prevention guidance is to test if you are exhibiting COVID-19 symptoms – whether or not you’re vaccinated against the coronavirus.

Those who have been in close contact with a confirmed COVID-19 case should also get a test. For vaccinated individuals, the CDC says to wait five to seven days after exposure. Unvaccinated people should test immediately. If the test is negative, try again five to seven days after exposure.

Dr. Bill Janssen, critical care specialist with National Jewish Health, said the highly contagious omicron variant may be changing that timeframe slightly.

“The omicron variant seems to be more infectious, in general. Before, if you had an exposure to a person, unless you were in really close contact in a room that didn’t have good ventilation or airflow, your chances of getting infected were not as high as with omicron,” Janssen said.

Janssen said a positive test may show up sooner than the typical five-day mark with this new variant. He said the type of test is also important in timing.

“Your likelihood of getting a positive in someone that’s infected is greater with a PCR early on in their course. The rapid test is not quite as sensitive as the PCR. Super early in their course, someone could have an infection but the rapid test could miss it,” Janssen said.

If you do test positive, you’ll need to isolate yourself from others for five days. At the end of five days, if you have no symptoms, you can return to normal activities but must wear a mask everywhere—even at home around others—for at least five more days.

If you’ve been in close contact with someone who has COVID-19, you’ll also need to self-quarantine, unless you’ve received a booster shot.

The White House is working on a way to get rapid tests out to every American who wants one in January – but that doesn’t help people who think they were exposed over Christmas or are hoping to be among friends on New Year’s Eve.

In the meantime, rapid tests you can buy in drugstores are a good choice and give reliable results when used properly, doctors say. That’s if you can find one – many stores are selling out quick or out of stock entirely amid the surge.

The Associated Press contributed to this report.