US authorities are confident most states will soon reach and pass a peak in coronavirus Omicron variant cases, even as hospitals struggle to cope with the current surge, Joe Biden’s chief medical adviser said on Sunday.

“I think [we’re] as confident as you can be,” Anthony Fauci told ABC’s This Week. “You never want to be overconfident when you’re dealing with this virus, because it has certainly surprised us in the past.

“But, if you look at the patterns that we have seen in South Africa, in the UK and in Israel, and in the [US] north-east and New England and upper midwest states, they have peaked and started to come down rather sharply.

“There are still some southern states and western states that continue to go up but if the pattern follows the trend that we’re seeing in other places … I believe that you will start to see a turnaround throughout the entire country.”

Fauci also predicted “a bit more pain and suffering with hospitalisations in those areas of the country that have not been fully vaccinated or have not gotten boosters”.

But, he said, “we do know – and these are the recent data that have come out – that even with Omicron, boosting makes a major, major difference in protecting you from hospitalisation and severe outcomes.

“So things are looking good. We don’t want to get overconfident. But they look like they’re going in the right direction right now.”

More than 865,000 people have died in the US during the coronavirus pandemic.

Fauci said Omicron “looks like” it is causing less severe disease than other variants, though “it’s by no means exempt from making people sick and putting them into the hospital, particularly those who are not vaccinated”.

That relative lack of severity, he said, helped efforts to get Covid under control.

“Control means you’re not eliminating it, you’re not eradicating it, but it gets down to such a low level that it’s essentially integrated into the general respiratory infections that we have learned to live with.

“I mean, we would like them not to be present, but they’re there. But they don’t disrupt society. They don’t create a fear of severe outcomes that are broad. You will always get some severe outcomes with respiratory infections. Even in a good pre-Covid era, you have always had that. We’d like it to get down to that level where it doesn’t disrupt us, in the sense of getting back to a degree of normality.

“That’s the best-case scenario. We have got to be prepared for the worst-case scenario. I’m not saying it’s going to happen, but we have to be prepared, which is, I think, that we get yet again another variant that has characteristics that would be problematic, like a high degree of transmissibility or a high degree of virulence.”

According to the Centers for Disease Control and Prevention (CDC), 75.5% of eligible Americans have received at least one vaccination dose and 63.3% are considered fully vaccinated. However, only 39.7% (or 53.2% of those eligible) have had booster shots.

Further boosters could be recommended, Fauci said, once it is known how long a third shot of an mRNA vaccine or a second of the single-shot Johnson&Johnson vaccine will last.

“Certainly you are going to see the antibody levels go down,” he said. “That’s natural, but … it is quite conceivable, and I hope it’s true, that the third-shot boost will give a much greater durability of protection. We’re following that very carefully.

“And when I say protection, I mean protection against severe disease. You are going to see breakthrough infections as we’ve seen now, even in boosted people, but for the very most part, they’re mild or even asymptomatic.”

Fauci also said supplies of Covid tests still had to be improved. The Omicron surge has coincided with problems which the Biden administration is attempting to solve, including by offering free at-home tests.

Fauci was asked if it was safe to send children to school without a mask, in states where mandates are being removed, often due to political pressures.

“We want to get the children back to school,” he said. “And the way you do that, you … surround the children with people who are vaccinated. For the children who are eligible to be vaccinated, get them vaccinated, and provide masks … as well as ventilation to make sure that you can get a respiratory infection at its lowest level of infectivity.

“All of those things go together and masking is a part of that.”