Calm down about omicron – UK’s immunity is different to South Africa’s, says expert

Britain should “calm down” about omicron because new research suggests that UK immunity will be very different to South Africa and vaccines are holding up well, a leading immunologist has said.

Danny Altmann, the professor of immunology at Imperial College London, said he had been initially terrified after seeing the amount of worrying mutations that the omicron variant carried.

However, at a briefing on Friday, he said he had been “calmed” by real world data, showing that the majority of hospitalised patients are unvaccinated. His own new research also suggested that immunity among the British population is likely to be different to that of South Africa.

The study from Imperial and Queen Mary University of London showed that people become “imprinted” with a specific immune profile after encountering coronavirus, its variants and the vaccines, and this dictates how well they will fight off new variants.

The paper showed that those who contracted the original Wuhan strain had fewer antibodies capable of fighting off the delta strain, but those who became infected later with alpha had developed antibodies better attuned to the new variant.

It suggested that in countries such as South Africa, which have encountered different variants and have far lower vaccine uptakes than Britain, the immunity of the population will not be the same.

“By now, 19 or 20 months into the pandemic, many of us on planet Earth have very different patterns of protective immunity to Sars-Cov-2 variants and these have been shaped by prior infection, plus vaccine exposures,” Prof Altmann said.

“That’s what we mean by the term ‘immune imprinting’. I think we’ve been careful about any predictions about what omicron means to the UK, because we’re in such a different context here, in terms of an enormous background of delta caseload and higher vaccination rates.

“I was one of the people who was quite fast to say I was terrified by the mutations. And I’m still kind of terrified by them. But I’m also kind of calmed by the real life on-the-ground data as it looks like even in South Africa, with low vaccination uptake, vaccines are holding up to some extent against it.

“What it means for this country is I think we can calm down. The jury’s out. We’ve got a high level of vaccination and a backdrop of delta.”

Doctors in South Africa also said that vaccinated patients with the omicron variant are having only mild to moderate symptoms, while the country’s National Institute for Communicable Diseases said that 87 per cent of hospitalised cases were unvaccinated.

Prof Altmann added: “I guess that might mean that lots of other stuff that we’re not measuring is protecting them, including their T-cell memory and B-cell memory.”

Research released by several South African universities on Thursday showed that omicron appears to increase the risk of a reinfection by 2.39 times compared to the original Wuhan strain, signalling that the mutated virus can escape immunity.

However, the Imperial academics warned against transferring the South African findings to a British context.

Rosemary Boyton, the professor of immunology and respiratory medicine at Imperial, and co-author of the immunity paper, said: “If you have a different immunological history, in terms of the types of spike that you’ve encountered, then you will have a different repertoire of immune responses.

“And so it does make it extremely difficult to make those broad comparisons. Our current vaccines are pretty good. They do protect against hospitalisation, and death.”

The new immunity paper was published in the journal Science.