The impact of the new Omicron variant of the Covid virus will be determined by three major issues. What is the transmissibility of this variant? How good is it to get rid of the T-cells that make up a person's immune defences? What are the chances that it will cause a severe illness that could lead to the death of a person?
Evidence suggests Omicron has the potential to cause serious disruption, but scientists are struggling to find definitive answers to these important questions. Prof Kao of Edinburgh University says that the situation is very finely tailored and could go in many different directions.
Where has the virus been found?
The Omicron variant has been found in 38 countries, but no deaths have yet been reported. The US and Australia are the latest countries to confirm that the variant is transmitted locally. The UK Health Security Agency announced on Friday that 75 more cases of the Covid-19 Omicron variant had been identified in England, bringing the total number of confirmed cases to 104.
Many nations that were already suffering from soaring numbers of Covid-19 cases caused by the Delta variant have imposed new restrictions on travel as a result of Omicron.
How fast is the variant spreading?
Omicron has spread quickly in South Africa. The country recorded 8,561 cases on 1 December, compared with 3,408 reported on 26 November. There were a few hundred cases in November. The National Institute for Communicable Diseases (NICD) in South Africa confirmed that Omicron is spreading quickly.
Omicron can cause three to six times the number of infections as Delta over the same time period, according to an evolutionary biologist at the Catholic University of Leuven in Belgium. He told the journal Nature that the virus has an advantage over us.
The case numbers doubled every five days when the Delta variant spread in the UK. Scientists are watching Omicron cases to see how quickly the variant is affecting the population of Britain.
How easy is it for the variant to evade the anti-viruses?
Scientists are clear on this question. Evidence shows that Omicron has an advantage over other variants. Prof Francois Balloux, director of the Genetics Institute at University, said that they can be fairly confident that Omicron tends to be better able to reinfect people who have been previously infections and received some protection against Covid-19.
That is clear and was anticipated from the changes we have found in its structure. These make it more difficult for the immune system to fight the virus.
This point was supported by a Reading University professor. There is no indication as to how this immune evasion happens, although it can be presumed to be because of decreased antibody binding to Omicron's spike protein. But decreased T-cell immunity can't be excluded as a factor.
How might vaccines fare against the variant if the power of previous infections is reduced?
Most scientists are more optimistic about the power of jabs than they were previously. Prof Peter Openshaw of Imperial College London said it was unlikely that this variant would evade vaccines. We need more lab and real world data to determine the degree of protection in those who have been vaccined.
How likely is it that Omicron will cause hospitalisation or death?
Omicron has not been known for a long time to be able to cause serious illness. Early evidence gives some grounds for optimism. The hospitalisation rates we would have expected with similar numbers of cases of Alpha or other variant are not being translated by the number of Omicron infections.
Even if the reduction in serious risk is correct, it is still balanced by the variant's ability to cause more harm.
It would put pressure on a nation's health service if we got high levels of hospitalisations.
People in high-risk groups might be affected by Omicron.
It's too early to know how the variant will affect the elderly or other high-risk groups. Some scientists are concerned. Kao said the big issue was the elderly population.
The variant has been circulating in younger age groups because they are the ones who are relatively protected. The variant may shift its profile to cause more infections in older people, who are more vulnerable to severe infections. The reasoning is easy to understand. The built-up immunity in the elderly will be less meaningful if the variant is able to evade the immune response of young people. That is a real worry.
The health service was at risk of overload before Omicron appeared. It was perfect. There is a chance of serious seasonal flu returning to increase the burden on hospitals. Any shift towards increased transmissibility, a shifting of age profiles, vaccine evasion, or more severe disease will put us in a more dangerous situation. Short-term indicators will be helpful, but it will probably be a little while before we can rule out worse scenarios.
