Washington, Jan 2 (IANS): Even after causing mild illness, people infected with Omicron are likely to suffer from long Covid, top infectious disease expert Dr. Anthony Fauci has said.

Data emerging from studies in South Africa, the US and the UK, has shown that Omicron causes mild illness, as well as causes lower hospitalisation rates. However, it is still too early to affirm how severe omicron is.

"Long Covid can happen no matter what virus variant occurs. There's no evidence that there's any difference between Delta or Beta or now Omicron," Fauci was quoted as saying in an interview with Spectrum News.

"We should always be aware that when people get symptomatic infection - anywhere from 10 to up to 30 plus per cent of people will go on to have persistence of symptoms," he added, noting that even mild cases are included in that possibility.

Long-term symptoms usually include shortness of breath, fatigue, difficulty concentrating, insomnia, and brain fog.

Fauci also noted that the words used to define vaccination status could soon change.

He said the label will likely evolve from "fully vaccinated" to "up to date," to identify when someone has been boosted, which Fauci called critical for protection against the virus, the report said.

"People should put aside this concern about a definition and say 'If I want to be optimally protected, I should get boosted'," he said.

According to Fauci, reaching a high vaccination rate will drive down Covid infections once and for all.

"I'm hoping that more people who are being recalcitrant about getting vaccinated wind up getting vaccinated, so we can have a uniform blanket of protection over the country," he said.

That blanket of protection, Fauci explained, could help the US diminish Covid-19 to "such a low level that it doesn't interfere with our function as a society".

"I'm always cautiously optimistic," Fauci said. "But I'm quite realistic. We need to do better with regard to vaccinations."