Out of 120 guests, all were vaccinated and, yet, more than half were then tested positive for Covid-19 … A festive evening in Oslo turned into a probable focus of infection with the Omicron variant, reinforcing fears about its high transmissibility and resistance to vaccines.
It all started with a company party on November 26 in the Norwegian capital: at the invitation of solar power producer Scatec, some 120 people, including one who recently returned from South Africa where the Omicron variant first began. been detected, meet at the Louise restaurant to celebrate Christmas ahead of time.
“All had been vaccinated, none showed symptoms and they had all carried out a self-test” before the meal, an official of the municipal health authorities, Tine Ravlo, told AFP on Friday.
“Everything had been done in order and no rule was broken,” she said.
However, a week later, the atmosphere is no longer at the party: 64 guests, or a large half of the 120 or so participants, tested positive for Covid. As of Friday evening, the Omicron variant had been confirmed in 13 cases and was deemed likely in others.
Still provisional, these numbers are likely to increase as testing analyzes progress.
Among the infected guests, none have so far developed a severe form of the disease, most showing mild symptoms in the form of headaches, inflammation of the throat and cough, according to Ms Ravlo.
– Largest outbreak outside South Africa –
“Our working hypothesis is that at least half of the 120 participants were infected with the Omicron variant during the party,” senior Norwegian Institute of Public Health official Preben Aavitsland told AFP.
That would make it “the biggest Omicron outbreak outside of South Africa,” he said.
According to the European Center for Disease Prevention and Control (ECDC), the number of known cases of people infected with this variant in countries of the European Economic Area (European Union plus Norway, Iceland and Liechtenstein) was 109 on Friday in mid-day.
“It is still too early to say whether this event is proof that the Omicron variant is more infectious than the Delta variant,” Aavitsland said. “Episodes of super-propagation also occur with the currently dominant Delta variant”.
Too early too, he said, “to say whether the clinical picture of the disease is different for Omicron infections than for Delta infections.”
After the appearance he described as “worrying” of this suspected outbreak of the Omicron variant, the Norwegian government on Thursday announced a series of health restrictions in Oslo and its region.
Since midnight (23:00 GMT), wearing a mask is compulsory in and around Oslo on public transport, taxis, shopping centers and shops where distance is impossible.
– Vaccine dams in danger –
Telecommuting has also become the rule where possible, the number of people in private indoor events is capped at 100, and patrons of bars and restaurants must register with alcohol to be served seated.
Christmas meals generally very watered and dear to the Norwegians, the “julebord” – like the one organized by Scatec – are not prohibited but several institutions and companies have canceled theirs.
“What we see is that Omicron is spreading very quickly and very widely, despite vaccination. It is appalling information in the course of this pandemic”, explains French epidemiologist Antoine Flahault.
Even in a Europe where people are quite widely vaccinated – 88% of the adult population is in Norway – “this may raise concerns that the vaccine dams against the progression of the new variant may not hold up,” says- he.
From a genetic point of view, the Omicron variant has an unprecedented number of mutations, including around thirty in the spike protein, the key to entry of the virus into the body. Some may be associated with greater transmissibility and decreased efficacy of vaccines.
According to the ECDC, the Omicron variant is likely to become the majority in Europe within “the next few months”.
Festivities like those organized by Scatec generate “significant risks, known since the start of the pandemic”, underlines Mr. Flahault. “They should unfortunately be banned in the midst of an epidemic wave”.