Omicron More Apt at Sidestepping Immunity, Though Less Contagious Than Feared – Danish Study

While the novel Omicron strain currently harrowing several European nations is better at getting past the vaccines and natural immunity, booster shots continue to have an effect, a recent Danish study has shown.

A Danish study has concluded that the Omicron strain has an edge over Delta in cracking the immunity.

A joint study by 19 researchers from the University of Copenhagen, Statistics Denmark, the Technical University of Denmark (DTU) and the States Serum Institute (SSI), which is still a preprint hasn't been peer-reviewed, measured the effect of Omicron against the previous Delta strain on nearly 12,000 households, Danish Radio reported.

While the SSI previously calculated that Omicron was twice as contagious as the Delta strain, the study indicates that it is only one and a half times as contagious, which SSI doctor Camilla Holten Møller labelled a “positive surprise”, suggesting that the outlook was “much brighter” than the worst-case scenarios.

Lone Simonsen, the head of the PandemiX Center at Roskilde University, said the overall conclusion is positive.

“For me, the suspicion has been that Omicron could have been as contagious as the measles. It isn't, and it is relieving,” Simonsen said.

However, the Omicron strain, which originated in South Africa and has since spread to become the dominant variant in several European nations, is far better at breaking through immunity from both vaccines and previous infections, Camilla Holten Møller emphasised.

“The vast majority of the households surveyed got their second shot four or five months ago, and there we can see that the protection against Omicron disappears. This is one of the reasons why Omicron has an advantage over Delta,” she said. “It is of course discouraging that it evades our immunity, which we have built up from the vaccines. Conversely, it is good news that the booster vaccines work to reduce further infection and against becoming infected,” she added.

However, Camilla Holten Møller concluded that Denmark is not on the top of the wave and expects it to peak at some point in January.

In mid-December, SSI's expert group predicted as many as 45,000 daily infections by Christmas Eve. However, the increase has not been so bad. While Denmark has indeed seen a record-breaking wave, resulting in the world's highest infection rate, it has “only” seen around 20,000 daily infections, which is more than in Russia, a nation of 144 million.