Washington, Dec 28 (IANS): The US Centers for Disease Control and Prevention (CDC) has shortened the isolation time for Americans infected with Covid-19 from 10 to five days.

"Given what we currently know about Covid-19 and the Omicron variant, CDC is shortening the recommended time for isolation from 10 days for people with Covid-19 to 5 days, if asymptomatic, followed by 5 days of wearing a mask when around others," said the agency in a statement on Monday.

The change is motivated by science demonstrating that the majority of SARS-CoV-2 transmission occurs early in the course of illness, generally in the one to two days prior to onset of symptoms and the two to three days after, according to the CDC.

"Therefore, people who test positive should isolate for 5 days and, if asymptomatic at that time, they may leave isolation if they can continue to mask for 5 days to minimise the risk of infecting others," said the US health agency.

The CDC has also updated its recommendation of quarantine period for those exposed to Covid-19. For people who are unvaccinated or are more than six months out from their second mRNA dose or more than 2 months after the Johnson & Johnson vaccine, and not yet boosted, CDC recommends quarantine for five days followed by strict mask use for an additional five days, Xinhua news agency reported.

Individuals who have received their booster shot do not need to quarantine following an exposure, but should wear a mask for 10 days after the exposure, said the agency.

"The Omicron variant is spreading quickly and has the potential to impact all facets of our society. CDC's updated recommendations for isolation and quarantine balance what we know about the spread of the virus and the protection provided by vaccination and booster doses," said CDC Director Rochelle Walensky.