Americans fully inoculated against COVID-19 can meet in small groups with other vaccinated people without wearing masks but should keep wearing them outside the home, the US Centres for Disease Control and Prevention says.

CDC director Rochelle Walensky said the agency’s new guidance for fully vaccinated individuals stipulated that they could also visit unvaccinated, low-risk people from one other household without masks.

The CDC advised fully vaccinated people that they should continue with many precautions such as avoiding medium- and large-sized in-person gatherings, wearing masks when visiting with unvaccinated people from multiple households or wearing masks when with people who are at risk for severe COVID-19.

“It’s important to realise… that still over 90 per cent of the population is not yet vaccinated, and that is our responsibility to make sure, in the context of 60,000 new cases a day, that we protect those who remain unvaccinated and vulnerable,” Dr Walensky said.

The public health guidelines address how vaccinated people can safely resume some more normal activities and contacts with those outside their households while the coronavirus is still widely circulating.

The recommendations came as about 30 million people, or 9.2 per cent of the US population, have been fully inoculated with COVID-19 vaccines made by Pfizer-BioNTech, Moderna and Johnson & Johnson, according to CDC data.

Nearly 18 per cent of the US population, or 58.9 million adults, had received at least one dose of a COVID-19 vaccine.

Currently authorised COVID-19 vaccines prevent people from becoming ill but not necessarily from being infected.

Data on whether vaccinated people can still spread the virus to unprotected people is sparse.

-with AAP