Scientists in South Africa grew live samples of the omicron variant and performed laboratory experiments to see if and how the omicron was affected by antibodies in blood samples from 12 people who had been vaccinated. Six of the people had also previously had Covid.
The world was waiting for these neutralizing studies to assess how well pre-existing immunity due to vaccination and previous infection will resist omicron.
The study shows how many antibodies are needed to stop the virus from replicating and is an early indicator of how well the disturbing new variant is working to bypass our immune system.
In reality, the picture is much more complex because the human immune system has other lines of defense that work in tandem with antibodies, such as T cells.
The new study is the first to show how omicron compares to previous variants, such as beta and delta, on a par and preliminary data shows that antibodies in blood samples are 41 times less effective for omicron than for strain 2020.
“That doesn’t mean vaccines will be 40 times less effective,” said Dr Muge Cevik, an infectious disease expert at the University of St Andrews who was not involved in the research.
However, it will be several weeks before real world data becomes available and more nuanced assessments are possible.
Before the emergence of omicron, the beta was the variant that scientists had found most apt to avoid antibodies.
In similar experiments, the team of academics found that beta only triggered a triple decrease in the number of neutralizing antibodies.
Real-world studies subsequently showed that beta reduced the ability of vaccines to prevent infection by about 40%.
“The results we present here with omicron show a much more extensive leak,” write the researchers of the new study.