By Rachel V. Thomas

New Delhi, Jan 7 (IANS): Although studies claim Omicron to be mild, there is no plausible reason to think that the highly-transmissible variant will not cause long Covid conditions among survivors, experts said on Friday.

According to the Centers for Disease Control and Prevention (CDC), long Covid "is a range of symptoms that can last weeks or months after first being infected with the virus that causes Covid-19 or can appear weeks after infection. Long Covid can happen to anyone who has had Covid-19, even if their illness was mild, or if they had no symptoms".

More than 50 long-term effects of Covid-19 have been detected. But the most common symptoms reported by Covid survivors four to 12 weeks after acute infection are headache, fatigue, sleep disturbance, concentration difficulties and abdominal pain. Even in mild cases, many Covid patients suffer from long-term residual symptoms.

Studies have shown that up to one in seven children and young people who caught SARS-CoV-2 may also have symptoms linked to the virus about three months later.

But, the risk of long Covid with Omicron has not been taken seriously as before. One reason could be lack of proper data.

"It is too early to know what the prolonged symptoms related to Covid might be for a new variant that has only recently been reported. In the acute phase, severe fatigue and myalgia appear to be prominent symptoms, and there might be symptoms of long Covid in a fraction of these individuals," Lancelot Pinto, Consultant Pulmonologist and Epidemiologist at P.D Hinduja Hospital & MRC, Mumbai, told IANS.

While infections are mild, there is "no plausible reason to believe that the incidence of long Covid with Omicron will be less than what is reported with Delta, or Alpha", she added.

In a recent interview with Spectrum News, top US infectious disease expert Anthony Fauci was also quoted as saying that even after causing mild illness, people infected with Omicron are likely to suffer from long Covid.

"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 said.

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

In line with this, a research by Cedars-Sinai Medical Center, Los Angeles, showed that Covid infection, even if mild, can trigger an immune response that lasts longer than the initial infection and recovery.

The study showed that the presence of elevated autoantibodies after mild or asymptomatic infection, as well as their persistence over time, Jerusalem Post reported.

However, there are some experts who disagree and say that Omicron may not cause long Covid.

According to Nikhil Modi, Consultant Pulmonology/ Respiratory Medicine, Indraprastha Apollo Hospitals, as Omicron causes a mild disease, "we are expecting that the Long Covid will not be seen in this variant of the virus".

"It is because the symptoms are already settling within a few days and as we are seeing that the inflammatory markers are either not rising or are significantly mild in patients being infected with this variant.

"Long Covid symptoms are the resultant factor of the inflammation being left by the virus, since this variant is not giving rise to the inflammatory factors we are not expecting long Covid to be a part of Omicron variant," Modi explained.

The super mutant Omicron strain first emerged in late November in South Africa and Botswana. It has since spread to more than 100 countries, outpacing the Delta strain in many countries.

Data 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.

But World Health Organization Director-General Dr Tedros Adhanom Ghebreyesus, in his latest address said that while Omicron does appear to be less severe compared to Delta, it does not mean it should be categorised as ‘mild' and just like previous variants, Omicron is hospitalising people and it is killing people.

In fact, he stressed, the tsunami of cases is so huge and quick, that it is overwhelming health systems around the world, which means the variant is going to haunt people even after its virulence is over. This emphasises the need to take the cover of vaccines, masks, hygiene and social distancing.