Scientists are racing to establish the variant’s transmissibility, effect on immune system and chance of hospitalisation or death!
Three major issues will determine the magnitude of the impact of the new Omicron variant of the Covid virus will have on the nation and the rest of the planet. What is the transmissibility of this new Covid variant? How good is it at evading the antibodies and T-cells that make up a person’s immune defences? What are the chances it will trigger severe illness that could lead to the hospitalisation, and possibly death, of an infected person?
Scientists are struggling to find definitive answers to these critically important questions, although evidence already suggests Omicron has the potential to cause serious disruption. “The situation is very finely tuned and could go in many different directions,” says Prof Rowland Kao of Edinburgh University.
• Where has the virus been detected?
The Omicron variant has now been detected in 38 countries, although no deaths have yet been reported in any of these nations, according to the World Health Organization. The US and Australia have become the latest countries to confirm locally transmitted – as opposed to imported – cases of the variant. On Friday, the UK Health Security Agency announced that 75 more cases of the Covid-19 Omicron variant had been identified in England, bringing the total number of confirmed cases to 104.
As a result of Omicron, many nations that were already suffering from soaring numbers of Covid-19 cases caused by the Delta variant have imposed new lockdown measures and travel restrictions.
• How fast is the variant spreading?
Omicron has spread rapidly in South Africa, to the alarm of researchers worldwide. On 1 December, the country recorded 8,561 cases compared with a total of 3,402 reported on 26 November. In mid-November, only a few hundred cases were noted. South Africa’s National Institute for Communicable Diseases (NICD) in Johannesburg confirmed that Omicron is spreading quickly.
Tom Wenseleers, an evolutionary biologist at the Catholic University of Leuven in Belgium, estimates that Omicron can infect three to six times as many people as Delta, over the same time period. “That’s a huge advantage for the virus — but not for us,” he told the journal Nature.
When the Delta variant began its rapid spread in the UK, case numbers doubled roughly every five days. Scientists are now carefully monitoring Omicron cases to determine how swiftly the variant is affecting the population of Britain.
• How easily does the variant evade the body’s anti-virus defences?
On this question, scientists are clear. Evidence indicates that Omicron has an advantage over other variants in bypassing the immune system. “From what we have learned so far, we can be fairly confident that – compared with other variants – Omicron tends to be better able to reinfect people who have been previously infected and received some protection against Covid-19,” said Prof Francois Balloux, director of the Genetics Institute at University College London.
• If the power of previous infection to protect people is reduced, how might vaccines fare against the variant?
If previous questions raised fairly worrying responses from scientists, most are more optimistic about the power of jabs to safeguard people from Omicron. “It is extremely unlikely this variant will evade vaccines completely,” said Prof Peter Openshaw of Imperial College London. “The vaccines we have are remarkably effective against a range of other variants but we need more lab and real world data to determine the degree of protection in those vaccinated.”
• How likely is infection with Omicron to lead to hospitalisation or death?
This is the most difficult question to answer because Omicron has not been known for long enough to determine its ability to cause serious illness. However, early evidence does give some grounds for optimism. “The number of cases of Omicron infections does not seem to translate at this stage into the hospitalisation rates we would have expected with similar numbers of cases of Alpha or other variants,” said Balloux.
However, even if this reduction in serious risk proves correct, it is balanced by the variant’s apparent ability to infect more people.
“We could still get high levels of hospitalisations, and that in turn would put pressure on a nation’s health service.”
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