Covid-19. what is this sub version BQ.1.1, at the beginning of wave nine?

The ninth wave of Covid-19 is forming in France. According to Public Health France (SPF), 68,382 new cases of Covid-19 were confirmed this Wednesday, November 30 (+39% in seven days). The increase is due in part to the emergence of subversion BQ.1.1. It is more precisely a sub-gen of BA.5, itself a sub-spec of Omicron, which SPF calls “everywhere». BA.5 represents 93% of Omicron viruses circulating in France. It should be noted that currently only the Omicron version is circulating in the country.

Experts interviewed for this article agree that this BQ.1.1 subexchange is largely responsible for “traffic recoveryCovid-19 is treated with SPF. Be careful though, this data should be treated with caution due to the recent biologists strike. This may lead to data collection.

So what do we know about BQ.1.1? Le Figaro provides an update on this subversion that started gaining momentum last October.

• Will it become dominant in France?

Of course. “Within two weeks within a month unless another sub-exchange appears», wants to believe Yves Buson, epidemiologist and chairman of the National Academy of Medicine’s Covid cell. In its weekly epidemiologic bulletin 1^eh December, SPF claims that BQ.1.1 accounted for 49% of BA.5 sublines in the week of November 7-13, 2022, up 15 points over the three weeks. “This evolution of subspecies follows the classic pattern of viruses that tend to mutate. The resulting version is the most likely to be transmittedYves Buson recalls.

Obviously, subspecies all have an interest in being more contagious than other subspecies if he wants to impose himself. BQ.1.1 is about 30% more transferable than BA.5. “There are over 500 subspecies worldwide. Some are essential, and this is the case with BQ.1.1“, confirms Antoine Flaon, epidemiologist and director of the Global Health Institute at the University of Geneva.

Also included is a mutation that “leads to a decrease in the effectiveness of antibodies, whether due to vaccination or previous infection», assures Gilles Pialou, infectious disease specialist and head of the Department of Infectious and Tropical Diseases at the Tenon Hospital (AP-HP). Therefore, re-infection with Covid-19 can occur more quickly.

• Is it more dangerous?

Still hard to say. According to the first elements available to experts, the BQ.1.1 would not be more dangerous than its parent BA.5, the currently dominant version. “Still very hard to compare BA.5 and: BQ.1.1 at the level of danger. We can consider it about the same level as the other subspecies of Omicron», assures epidemiologist Yves Buson.

However, BQ.1.1 may have an effect on the most vulnerable people. This subtype is said to be resistant to monoclonal antibodies, a treatment used especially in immunocompromised people and the elderly. “BA.5 had already beaten multiple monoclonal antibody treatments– recalls Mircea Sofonea, professor of epidemiology at the University of Montpellier. Now it’s going to get even harder».

Therefore, is excess mortality to be expected in this type of population? “That’s the whole pointasks epidemiologist Antoine Flao. But it is not impossible in the most fragile people infected with BQ.1.1.».

• Do vaccines work against BQ.1.1.?

In terms of transmissibility, BQ.1.1 may be more vaccine evasive than BA.5, although the experts interviewed agree that real-life data are still lacking. The new so-called bivalent vaccines, which are effective against both the original strain of Covid-19 and the Omicron BA.1, BA.4 and BA.5 subtypes, and which are integrated into the vaccination campaign in September.should have continuous activity against severe forms and deaths [par rapport à l’efficacité des vaccins contre BA.5, NDLR]”, claims infectious disease expert Gilles Pialou.

The SPF also noted on November 16 that it has “no indication that BQ.1.1 is associated with a different clinical presentation or severity than other Omicron subtypes“. Vaccine efficacy against severe forms of BQ.1.1 may therefore be the same as against other Omicron subtypes.

Moderna, however, confirmed on November 14 that these bivalent vaccines have “exhibited strong neutralizing activity against BQ.1.1», in a study involving about 40 people. Fortunately.