The Centers for Disease Control and Prevention announced Monday that it was changing its recommendations for how long a person who is infected or exposed to COVID-19 should isolate based on emerging evidence that people are more likely to spread the virus during a five-day window.

The statement from the CDC said new data shows that people infected with COVID-19 are most likely to transmit it to others one to two days before their symptoms begin and the two to three days after they become symptomatic.

CDC Director Dr. Rochelle Walensky said that the updated guidelines “ensure people that can safely continue their daily lives,” while encouraging people to get vaccinated, and to get their booster shots if they’ve already been fully vaccinated.

According to data from South Africa and the United Kingdom, vaccine efficacy for people with two doses is 35% while a booster shot bumps the vaccine’s effectiveness up to 75% against infection. Los Angeles County health officials have reported an average of 8,734 new daily cases over the past four days, a dramatic increase from Dec. 1 when the county recorded 1,473 new COVID-19 cases.

Here are the new guidelines released from the CDC Monday: 

What should I do if I test positive? 

The new guidelines say, everyone, regardless of vaccination status, should stay home for five days. If you’re asymptomatic, you can leave your house after five days but the CDC recommends wearing a mask around others for an additional five days. People with fevers should still stay home until the fever goes away, according to the new guidelines.

What should I do if I’m exposed to COVID-19?

If you’ve received your booster shot or are within the window that your primary vaccines should still be effective (six months for Moderna/Pfizer and two months for Johnson & Johnson) the CDC is recommending wearing a mask around others for 10 days and getting tested on the fifth day, if possible. If you are symptomatic, get a test as soon as possible and stay home.

If you’re not boosted and are outside of the effective window for the vaccines or you’re unvaccinated the new guidelines suggest staying home for five days and continuing wearing a mask for five days. If you can’t quarantine, the new guidelines suggest wearing a mask for 10 days when around others.

UPDATE: COVID-19 surge hits Long Beach Fire Department; positive case count now up to 46