NEW YORK (NYTIMES) - After a rise in known infections this spring, new coronavirus cases in the United States have levelled off in recent weeks, even as hospitalisations continue to inch upward and new Omicron subvariants rapidly circulate.

The country is recording just over 105,000 new coronavirus cases a day, on average, a rate that has more or less held steady over the last month, according to a New York Times database.

That figure is sure to be an undercount, as more people have turned to at-home testing, the results of which often go unreported.

But other indicators are also showing signs of steadying: The number of patients hospitalised with the virus is still growing but doing so slowly, with the average hovering for most of this week around 29,000. Deaths have stayed below 400 a day for several weeks.

With key indicators far below their Omicron winter peaks, long-standing public health orders continue to be lifted. In one sign of recent change, travellers flying to the United States no longer need to provide a negative test result.

Dr Rochelle Walensky, director of the Centres for Disease Control and Prevention, explained the decision last week in part by pointing to booster shots and how Omicron had "generally caused less severe disease among those who are infected."

"We seem to be plateauing right now," said Dr Jennifer Nuzzo, a professor of epidemiology and inaugural director of the Pandemic Centre at Brown University's School of Public Health, who is monitoring the spread of two new Omicron subvariants, BA.4 and BA.5, which have been gaining ground in the United States.

"What is a little unclear to me is whether BA.4, BA.5, is going to see another bump," she said. "But my best guess is, we are not going to see another giant peak until possibly later in the summer for the southern states, and the fall and winter."

The current outlook varies from place to place.

In Alameda County, California, which includes Oakland, officials reinstated a mask order earlier this month, citing growing hospitalisations locally. In Sacramento, California, and in Philadelphia, school officials have added mask requirements for summer school amid new subvariants and rising case rates.

But in New York City, where cases slowed recently, Mayor Eric Adams, who had previously lifted a mask requirement in schools, announced last week that masks are now optional for toddlers in day care and preschool.

Children younger than 5 are the last remaining group not yet eligible to be vaccinated.

A committee of experts advising the Food and Drug Administration voted Wednesday to recommend that Pfizer-BioNTech and Moderna's paediatric coronavirus vaccines be authorised for that age group.

Authorising those vaccines could offer relief for many families, who have been juggling day care closures and lingering fears that their children could be among the few who develop a serious case of CovidD-19.

"The biggest impact is you take away the rare chance of something bad happening," said Dr Paul Offit, director of the Vaccine Education Centre at Children's Hospital of Philadelphia, who is part of an advisory panel to the Food and Drug Administration.

But experts do not expect the availability of paediatric vaccines for young children it to change the overall trajectory of the pandemic.

Many children have already been infected with the virus - by one estimate, as many as 75 per cent as of February. And vaccine uptake among children overall has been low.