Experts in Singapore, which is seeing a surge in Omicron cases, have warned that the new and supposedly more contagious variant is likely to replace Delta over the coming weeks as the dominant global variant, with the virus being fitter and having a reproductive advantage.
While Delta is still the most common variant in all continents except Africa, Omicron is spreading very quickly, said Dr Sebastian Maurer-Stroh, executive director of the state-owned Agency for Science, Technology and Research’s Bioinformatics Institute.
Of the genome submissions sent to the Munich-headquartered Gisaid, a data science initiative that provides the shared genome platform for Covid, the Omicron strain has comprised between 7 per cent and 27 per cent of new submissions over the past month, up until Tuesday. The figures refer to all continents except Africa.
“From current data, it looks like Delta will go down over time relative to Omicron,” The Straits Times reported, quoting Dr Maurer-Stroh, who is part of the global team that maintains Gisaid.
The new variant was first detected in South Africa on November 11, and then in Botswana and Hong Kong, before it rippled across more than 110 countries, as at last weekend.
Omicron is already dominant in Australia, Russia, South Africa and the United Kingdom, noted Professor Dale Fisher, a senior consultant at the National University Hospital’s Division of Infectious Diseases.
“We are seeing a global transition from Delta to Omicron because with a greater transmissibility, the virus is fitter and has a reproductive advantage,” said Dale Fisher.
But he added a caveat that the reports of Omicron rates may be biased as some countries do little gene sequencing, and those that do may be looking for a deletion in a specific spike gene to identify Omicron, instead of carrying out whole genome sequencing.
Singapore’s Ministry of Health, or MoH, said on its website that from December 24, COVID-19 cases that tested positive for the so-called S-gene target failure will be categorised as Omicron. The S-gene encodes the virus’s spike protein.
Based on local experience, if a person tests positive for the S-gene target failure, the individual is very likely to have the Omicron variant, said the Singapore MoH, noting that this practice aligns with those in other countries.
Singapore on Wednesday reported 170 new Omicron cases. According to Johns Hopkins University data, Singapore has recorded 278,750 COVID-19 cases and 826 deaths.
Dale Fisher said most experts in the field believe Omicron will replace Delta as the dominant strain. While the Delta variant has 13 mutations with nine on the spike protein, Omicron has about 50 mutations not seen together before, and 32 of them are on the spike protein.
Because of its mutations, the Delta variant attaches more effectively to human cell receptors, causing it to be more infective, said Fisher. But the Omicron variant made health authorities more concerned as the virus is even “stickier” because of its extra mutations, he added.
The rise and fall of new variants over time follows the laws of nature and the survival of the fittest, Dale Fisher noted.
Dr Maurer-Stroh said the environment in which two variants compete will also help determine which is more successful. “As immunity in the population increases from both vaccination and natural infection, severity goes down but even slightly better escape from the prevalent immune response can give one variant the extra edge over another,” he said. “This is also what we see with different flu variants every year.” Dr Maurer-Stroh said. “Because of the great benefit of vaccination including boosters, we see less severe cases.”
As Omicron and Delta continue to wrestle for dominance, some have wondered whether it would be possible to be infected with both strains at the same time. “This is possible but rare. And very quickly, only one variant would be the dominant infection in the body,” added Dr Maurer-Stroh.
International evidence indicates that the Omicron variant is likely to be more transmissible, but less severe than the Delta variant.
Not Same Disease We Were Seeing A Year Ago
The omicron variant that’s taking the world by storm is not “the same disease we were seeing a year ago,” a University of Oxford immunologist said, reinforcing reports about the strain’s milder nature.
The strain first discovered at the end of November appears to be less severe and even patients who do end up in the hospital spend less time there, John Bell, regius professor of medicine at Oxford, said on BBC Radio 4’s Today program.
“The horrific scenes that we saw a year ago — intensive care units being full, lots of people dying prematurely — that is now history in my view, and I think we should be reassured that that’s likely to continue,” Bell said.
Bell’s comments came after the U.K. government said it wouldn’t introduce stricter Covid-19 restrictions in England before the end of the year.
Infections have jumped by more than a quarter of a million in the past week, heaping pressure on Prime Minister Boris Johnson to respond. Health Secretary Sajid Javid late Monday said he’s monitoring the latest data and urged people to be careful, particularly at New Year celebrations.
Hope, Despair, Repeat: How India Spent 2021 Under Covid Shadow
2021 started with a hope of a return to pre-Covid lives after a year of pandemic. Curbs eased and travel picked up as people hoped for new beginnings. And then the second wave struck and not one person was left in the country who did not know the pain of losing someone close. As cases dropped and vaccination picked up, time started healing. The shadow of the third wave remained, but we started inching back to life. As the year ends, the curbs are returning and the third wave seems close. Hope and fear hang in a delicate balance as we welcome another new year under the shadow of the pandemic.
January: India begins vaccination drive, starting with healthcare workers, as case count remains low. By then, most states have scaled down curbs and travel has picked up.
February: Daily case count falls below the 9,000-mark for the first time in months. Domestic travel picks up and the country breathes a sigh of relief, unaware of what’s coming.
March: The spike begins again. India records a daily case count of 68,020, highest in five months. In many states, restrictions make a return.
April: Vaccinations were opened up to all over the age of 45. The daily case numbers keep rising exponentially, crossing grim milestones of 1 lakh, 2 lakh and then 3 lakh new infections in a day. Health infrastructure is found wanting in face of the surge and the squabble for beds and oxygen supply begins.
April 23-May 1: National capital Delhi witnesses nine days of Covid hell as people start dying in the long wait for hospital beds and oxygen supply. Black marketing of oxygen cylinders and life-saving drugs begin and SOS messages do the rounds on WhatsApp groups of people desperately seeking help for their loved ones. Queues at crematoriums and burial grounds.
May: Daily case count crosses the 4 lakh mark and daily death numbers near 4,000. Vaccinations extended to all above the age of 18 but shortage of doses hits the pace of immunisation. Later in May, while the case count dipped, the death numbers kept rising, crossing the 4,500 mark.
June: Amid shortage of shots, the centre revises its vaccine policy, announcing free jabs for all and taking control of procurement and supply. Daily Covid counts continue to drop.
July: Many states ease curbs on public movement and activities as cases and positivity rates continue to drop in most parts of the country.
August: The easing of curbs continues as key cities remove deadlines for shops. In some cities, physical classes in schools resume partially. Hospital occupancy drop significantly.
September: More curbs lifted, public transport, including Delhi Metro, resumes services cautiously. Restaurants and pubs reopen after a year-and-a-half.
October: The festival season begins under the shadow of a potential third wave of Covid infections. Authorities appeal to the public to not let the guard down. India reaches 100-crore vaccination milestone.
November: Omicron emerges as the highly transmissible new variant from South Africa. International case counts start spiking again as India braces for another spike. Testing at airports stepped up.
December: Curbs back in Delhi, Mumbai and other key cities as daily case counts rise rapidly. India clears booster health workers, frontline workers and the elderly. Vaccinations set to begin in the 15-18 years age group as the threat of the dreaded third wave looms large.