Analysis by Tom Clarke, science and technology editor
This is the data scientists have been waiting for ever since the Omicron variant was first discovered.
It is very preliminary, and the numbers are subject to change. But those numbers are significant.
In people vaccinated against COVID-19 with two jabs of the Pfizer vaccine, the ability of their antibodies to neutralise Omicron was reduced by between 20 and 40 times compared to the original COVID variant against which all our vaccines are made.
It’s a huge reduction compared to variants that we have seen before.
The Beta variant (previously known as the South Africa variant) was one of the strongest variants showing this “immune escape” but based on this analysis the omicron variant is five to ten times better at evading antibodies.
While the effect observed in this study is significant, it’s a lot better than some immunologists had feared. Some were privately worrying that vaccines may have no impact against Omicron at all.
“We saw a lot of escape,” said Alex Sigal at the Africa Health Research Institute in Durban, who led the study. “But I think the news is pretty good.”
The fact antibodies from vaccines still recognise Omicron is significant. Especially as there are other parts to the immune system like T-Cells which could work against it too.
But the most promising finding is the fact that people who had been infected with COVID-19 previously, as well as being vaccinated, had much improved protection against Omicron.
This would indicate that in places like South Africa, where infection rates have been high in the past, the impact of Omicron could be reduced. It also bodes well for booster vaccination programmes like the one in the UK.
More studies, on larger numbers of people, will be needed to confirm these results. But they are the first direct evidence we have of how much of a challenge Omicron might turn out to be.