The new Omicron variant of coronavirus, which is driving a new wave of infections across the world, may infect the same person twice, experts have said. According to US epidemiologist Eric Feigl-Ding, an Omicron reinfection is certainly possible if the first Omicron infection was of a 'low-dose' that did not stimulate the immune system enough.A person may also end up getting re-infected if they have a heavily compromised immunity."There are lots of recent anecdotes about new Omicron reinfections after a recent Omicron infection. It’s certainly possible if your first Omicron infection was a low-dose one that didn’t stimulate your immune system enough or if you’re immunocompromised. Be careful folks," the epidemiologist said in a tweet. His comment came in response to a news story, which had quoted Stanley Weiss, MD, professor at the Rutgers New Jersey Medical School, as saying that one patient can get the Omicron infection twice. “Omicron is highly contagious and it would appear to not induce fantastic protective immunity,” said Weiss. Weiss had cited a recent lecture he attended from a virologist in South Africa, where Omicron first emerged, who said that doctors in the country had seen several people who had Omicron reinfections.Prior to this, experts had pointed out that Omicron is able to infect people who have had past infections, and that it causes milder symptoms in some people with some immunity. According to a study by the Imperial College London, the risk of reinfection with the Omicron coronavirus variant is more than five times higher and it has shown no sign of being milder than Delta. The protection afforded by past infection against reinfection with Omicron may be as low as 19%, Imperial College (ICL) said in a statement. The researchers found a significantly increased risk of developing a symptomatic Omicron case compared to Delta for those who were two or more weeks past their second vaccine dose, and two or more weeks past their booster dose.A new variant of Covid-19 was first reported to the World Health Organisation (WHO) from South Africa on 25 November. As per the WHO, the first known confirmed B.1.1.529 infection was from a specimen collected on 9 November this year.On 26 November, the WHO named the new Covid-19 variant B.1.1.529 as 'Omicron'. The WHO has classified Omicron as a 'variant of concern'.