Vaccinated and test positive? What to know about omicron, COVID for this holiday season.

As COVID-19 cases surge, fueled by the highly transmissible omicron variant of the coronavirus, Americans wonder how to approach the holidays and safely travel and gather with friends and family. 

The pace of new cases in the USA is up 41% compared with a month ago, according to a USA TODAY analysis of Johns Hopkins data. For much of December, cases hovered around 120,000 but have jumped to more than 130,000 a day.

As of Saturday, the omicron variant accounted for 73.2% of new COVID-19 infections in the nation, the Centers for Disease Control and Prevention reported. The week ending Dec. 11, it accounted for 12.6% of new cases. 

Get COVID-19 updates right to your inbox:Sign up for our newsletter, Coronavirus Watch, here

Health experts said COVID-19 vaccines are less effective against the new strain, which may lead to more breakthrough infections. Boosters provide more protection against omicron, but the CDC reported only 30% of the eligible population has received their booster.

Here are answers to some common questions: 

Can you safely gather with family for the holidays?

Though the easy answer is to stay home, it's important to recognize how challenging the past year has been on families and the need to see loved ones around the holidays, said Akhil Bindra, a pulmonologist at the Cleveland Clinic.

"Being conscientious of that, there is a safe way to do it, but there's always some risk," Bindra said.

The best way to protect loved ones from severe disease is to get vaccinated and boosted, he said. Getting tested for the virus before you gather inside is a good idea, even if you don't have symptoms, he said.

Wearing a mask indoors will add another layer of protection, he said, acknowledging it may not be realistic to expect of all families.

Tuesday, presidential health adviser Anthony Fauci said vaccinated Americans don't need to cancel their plans. "If you don’t have the availability of the test and you are fully vaccinated and boosted, you should feel comfortable having a holiday meal or gathering with family members who are also vaccinated and boosted," he said on NBC's "Today."

What do you do if you have a close contact to COVID-19?

The CDC defines close contact as being within 6 feet of someone with COVID-19 for a cumulative total of 15 minutes or more over a 24-hour period.

The agency urges unvaccinated people quarantine if they’ve had close contact with someone with COVID-19, which entails:

• Staying home for 14 days after your last contact with the infected person.
• Watching for symptoms such as a fever of 100.4 degrees, cough or shortness of breath.
• Staying away from people you live with, if possible, especially those who are at higher risk for severe disease.

The CDC recommends consulting your local health department’s website for more information on quarantine. In some states, unvaccinated individuals can shorten their quarantine to 10 days without testing if they don’t develop symptoms or seven days upon receiving a negative test result.

Misinformation about COVID-19 is spreading:Experts explain why and how to spot false claims.

COVID-19 winter:Stressed hospitals, weary nurses brace for another surge

What 'super immunity' looks like:Full vaccination against COVID-19 and a breakthrough infection

People who are fully vaccinated  do NOT need to quarantine after contact with someone who had COVID-19 unless they develop symptoms, the CDC said. They should still get tested five to seven days after their exposure and wear a mask in indoor public settings for 14 days after exposure or until they get a negative test result.

When do you become contagious with COVID-19?        

A person infected with COVID-19 may be contagious 48 hours before symptoms start, health experts said. Early studies have shown people may be most likely to unknowingly spread the virus to others during that initial two-day period. 

How soon after contact with infected person should you get tested? 

The CDC recommends people get tested five to seven days after exposure and wear a mask in indoor public settings for 14 days after exposure or until they get a negative test result.

Omicron's spread:What it could mean for holiday plans

Asymptomatic COVID-19:More than 40% of people with COVID-19 never show symptoms, study finds

When COVID-19 cancels vacation:How to get a refund for your Airbnb or Vrbo rental

What should you do if you're vaccinated, test positive and feel sick?

Regardless of vaccination status, health experts said, Americans should not travel to see family or friends if they’ve tested positive for the coronavirus. Unfortunately, that may mean canceling holiday plans. 

According to the CDC, people who test positive for the coronavirus and experience symptoms should:

• Monitor their symptoms. If you’re having trouble breathing, persistent pain, pressure in the chest or confusion, seek emergency medical care immediately.
• Stay in a room separate from other household members, if possible.
• Use a separate bathroom, if possible.
• Avoid contact with other members of the household and pets.
• Don’t share personal household items.
• Wear a mask when around other people.

The CDC said a person infected with COVID-19 should isolate from people for 10 full days, counting Day 1 as the first full day after symptoms developed. After isolation, health experts said, it’s not always necessary to retest.

“A positive test doesn’t necessarily mean you have to wait another 10 days because we know that these tests can stay positive for a while,” said Purvi Parikh, an allergist and immunologist with the Allergy and Asthma Network, a nonprofit for allergy, asthma and immune conditions. “After 10 days, it’s very unlikely you’ll be contagious.”

She recommended rest, hydrating with lots of fluids and over-the-counter pain medication to alleviate symptoms during the isolation period.

What if you're vaccinated and asymptomatic and test positive?

Even if you’re asymptomatic, health experts said, it’s important to isolate after testing positive for the coronavirus.

If you test positive for the coronavirus and never develop symptoms, the CDC said, Day 0 is the day of your positive viral test and Day 1 is the first full day after your positive test.

If you develop symptoms before the 10-day isolation period is over, the agency said, your period must start over with Day 0 being the first day of symptoms and Day 1 the first full day after symptoms develop.

Even if symptoms never develop, the CDC recommended following the same rules of isolation as someone who does have symptoms, including avoiding contact with other household members, using separate facilities, not sharing personal items and wearing a mask. 

What if you're unvaccinated and test positive?

If you’re not feeling sick and have yet to test positive for the coronavirus, health experts urged unvaccinated Americans to get vaccinated as soon as possible.

Those who tested positive for the coronavirus and are unvaccinated should follow the same isolation rules as people who are fully vaccinated and infected.

People who are unvaccinated are more at risk of severe disease, hospitalization and death, Parikh said, which means they should be extra vigilant of symptoms that may require emergency care.

Regardless of vaccination status, people who are at high risk for severe disease, such as those over 65, are immunocompromised or have underlying medical conditions, should call their doctor for early treatment options.

“You should strongly consider monoclonal antibody infusion preferably two to three days after (testing positive),” Parikh said. “It will lessen your chances of needing to be admitted in the hospital or dying of COVID-19.”

Why are COVID-19 cases rising? And why are hospitals filling up if omicron is milder?

Bindra, with the Cleveland Clinic, said the majority of cases at his hospital are unvaccinated people, highlighting the need to get vaccinated. "It's still not too late," he said.

The omicron surge has helped fuel the rise in cases, he said. According to the CDC, omicron can spread among the vaccinated and people who are asymptomatic. Bindra said among the small number of vaccinated cases at his hospital, most are older or immunocompromised patients.

Though more research is needed on the signs and symptoms of omicron compared with other variants, Bindra said it's important to remember that delta is still circulating, which can account for many longer-term and intensive care unit hospitalizations.

Can you get boosted or vaccinated if you have COVID-19?

The CDC said people who have COVID-19 should not get vaccinated right away. If you are asymptomatic, wait until you meet the criteria for leaving isolation to get a shot. If you are symptomatic, wait until you have recovered and meet the criteria to leave isolation, the CDC said.

Can the virus change as it spreads?

Yes. Omicron is a variant of the coronavirus, similar to delta. They both occurred when genetic mutations occurred to the virus.

"I think the longer the virus can exist – which is now, existing for about two years – (there's a) higher chance of it continuing to mutate. So I don't think any of us expect that this one will count as the last mutation," Bindra said.

Contributing: Mike Stucka and Ryan Miller

 Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.

Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.