WORLDWIDE RACE TO HALT THREAT POSED BY OMICRON
▶ Scientists study how quickly variant spreads and severity of infection
As the Omicron coronavirus variant leads countries around the world to impose travel bans on many African nations, scientists are racing to understand the latest mutation.
There are signs that it may spread faster than earlier variants, and concerns that it may evade the protection conferred by vaccines or prior infection.
But much uncertainty remains over a variant listed as being of concern by the World Health Organisation only four days ago.
Q
What symptoms does Omicron cause?
A
There has been an increase in hospital admissions in South Africa, where Omicron was first identified. But the WHO says this may simply reflect growing case numbers.
Doctors there who have seen Omicron-infected patients said that symptoms were mild, although patients tended to be younger and so less likely to develop severe disease.
Dr Angelique Coetzee, who was among the first to have patients with the new variant, said symptoms were “very, very mild”. These included body aches and pains, headaches and a “scratchy” throat, but no effect on taste and smell.
“What we are seeing clinically in South Africa is extremely mild,” she said. “We haven’t admitted anyone. I spoke to other colleagues of mine — the same picture.”
However, Dr Paul Burton, the chief medical officer of coronavirus vaccine manufacturer Moderna, said the picture remained unclear.
“Until we see how this virus behaves in populations of older people … we really will not get a handle on exactly how severe the disease could be,” he said.
How easily does Omicron spread?
Omicron is suspected to have led to a rapid increase in Covid-19 cases in South Africa in the past two weeks, suggesting that it may spread more easily than other variants. This includes even Delta, which is passed on more easily than other variants.
However, the WHO said it was “not yet clear” whether the surge in cases was owing to Omicron and more studies were under way.
Prof Eskild Petersen, of Aarhus University Hospital in Denmark, said the rise in cases in Gauteng, the South African province where cases have surged, could have been due to a “super-spreading event” rather than changes to the virus.
“We have to wait and see if it’s spreading to people who are fully vaccinated and have received their third shot,” he said.
How effective are vaccines and treatments against Omicron?
Because Omicron has many mutations in its spike protein, it may be better able to evade protection from vaccines and prior infection.
The spike protein is the part of the coronavirus that latches on to human cells, and is also the part recognised by antibodies produced by a person who has been vaccinated.
Moderna said results from laboratory tests indicating how likely Omicron is to evade the protection from vaccines should be available within two weeks. If needed, the company could produce a reformulated vaccine by early next year.
Pfizer chief executive Albert Bourla said if there was a need for a new vaccine, his company could make four billion doses.
Other vaccine producers are carrying out similar tests.
Early data indicates Omicron is more likely than other variants to reinfect people who have already had Covid-19.
The WHO said that treatments involving certain drugs — corticosteroids and interleukin-6 receptor blockers — “will still be effective” against severe Covid-19, even if caused by Omicron.
These drugs are used against severe Covid-19 to prevent the immune system from overreacting, a main cause of death.
Other treatments, such as antivirals, “will be assessed” to determine if they are still effective.