The Omicron variant of the coronavirus is spreading faster than the Delta variant and is causing infections in people already vaccinated or who have recovered from the COVID-19 disease, the World Health Organization (WHO) has said.
WHO chief scientist Soumya Swaminathan said on Monday it would be “unwise” to conclude from early evidence that Omicron is a milder variant than previous ones.
Soumya Swaminathan told Geneva-based journalists that “with the numbers going up, all health systems are going to be under strain.”
She warned that South Africa and other places reporting lower hospitalisation rates from Omicron had been hit hard in earlier waves, so many of the Omicron cases may have been reinfections.
“The variant may be behaving differently in people with prior immunity,” she said.
The variant is successfully evading some immune responses, she said, meaning that the booster programmes being rolled out in many countries ought to be targeted towards people with weaker immune systems.
“There is now consistent evidence that Omicron is spreading significantly faster than the Delta variant,” WHO director-general Tedros Adhanom Ghebreyesus told the briefing.
“And it is more likely people vaccinated or recovered from COVID-19 could be infected or re-infected,” Tedros said.
Their comments echoed the finding of a study by Imperial College London, which said last week the risk of reinfection was more than five times higher and it has shown no sign of being milder than Delta.
But while the antibody defences from some actions have been undermined, there is hope that T-cells, the second pillar of an immune response, can prevent severe disease by attacking infected human cells.
WHO expert Abdi Mahamud added: “Although we are seeing a reduction in the neutralisation antibodies, almost all preliminary analysis shows T-cell mediated immunity remains intact, that is what we really require.”
However, highlighting how little is known about how to handle the new variant that was detected last month, Swaminathan also said: “Of course there is a challenge, many of the monoclonals will not work with Omicron.”
She gave no details as she referred to the treatments that mimic natural antibodies in fighting off infections. Some drugmakers have suggested the same.
Ending the pandemic
In the short term, Tedros said that holiday festivities would in many places lead to “increased cases, overwhelmed health systems and more deaths” and urged people to postpone gatherings.
“An event cancelled is better than a life cancelled,” he said.
But the WHO team also offered some hope to a weary world facing the new wave that 2022 would be the year that the pandemic, which already killed more than 5.6 million people worldwide, would end.
It pointed towards the development of second and third generation vaccines, and the further development of antimicrobial treatments and other innovations.
“(We) hope to consign this disease to a relatively mild disease that is easily prevented, that is easily treated,” Mike Ryan, the WHO’s top emergency expert, told the briefing.
“If we can keep virus transmission to a minimum, then we can bring the pandemic to an end.”
Amid growing concern over Omicron, many governments are scrambling to roll out vaccine booster shots to populations, with early data suggesting that a third dose offers increased protection against the variant.
But the WHO has repeatedly voiced concern that such booster programmes could deepen already glaring inequity in vaccine access between wealthy and poorer countries.
Many vulnerable people around the world are still waiting for a first vaccine dose, and the UN health agency has said it is better to prioritise them over providing fully vaccinated health adults with boosters.
“If we are to end the pandemic in the coming year, we must end inequity,” Tedros said.