NEW VARIANT. This subvariant of Omicron is the majority in France. It accounts for 92% of positive Covid tests. The monoclonal antibodies Ronapreve and Evusheld could be used in preventative treatments against BA.2 What are the symptoms? How dangerous is it? Can you get infected again?
[Mis à jour le 11 avril 2022 à 15h40] BA.2 is a Subvariant of omicron, itself a variant of Sars-CoV-2. BA.2 and responsible for the recent epidemic resurgence. That symptoms of BA.2 infection are the same as those caused by Omicron: Fatigue, cough, fever… The bottom line BA.2 is majority in Francerepresent 92% of positive Covid tests analyzed by Public Health France according to the April 7 epidemiological update. He is more contagious than the sub-variant BA1 Omicron, which first appeared in France. But he doesn’t introduce himself no more danger. French researchers from the Pasteur Institute have investigated the effectiveness of Ronapreve monoclonal antibodies® (Combination of two antibodies developed by Roche/Regeneron) and Evus hero® (Combination of two antibodies developed by AstraZeneca) against the Omicron variant (BA.1 and BA.2) of the coronavirus. Ultimately, BA.1 and to a lesser extent BA.2 are less sensitive to Evusheld® and Ronapréve® as Delta. “Antibodies and corresponding sera have little or no activity against BA.1, however are more active against BA.2. Compared to Delta, the neutralizing activity against BA.1 is more reduced: it takes 344 times more antibodies to neutralize BA.1 and 9 times more to neutralize BA.2“explains Timothée Bruel, first author of the study published on March 23. What is this new mutation? from Covid-19? Is she contagious, dangerous, what omicron? that vaccination effective against this new variant? What are the Symptoms of BA.2 ? To update.
Definition: What is the new BA.2 variant?
“The BA.2 is a Subvariant of omicron. It is a “little cousin” of the Omicron variant“explained Jean-François Delfraissy, President of the Covid Scientific Council, at the microphone of Franceinfo in January. Called BA.2, it is a sub-line of Omicron like BA.1 (which has circulated so far) or BA .3. “That genetic sequence of BA.2 subvariant differs from that of BA.1 and shows in particular amino acid differences in the spike protein and other proteins. said the WHO in February 2022.”The latest data appear to confirm that BA.1 and BA.2 have similar severity and evasion of the immune response and therefore BA.2 is not considered a distinct variant but is included in Omicron VOC.” specifies Public Health France. However BA.2 “is the most contagious variant of the SARS-CoV-2 virus that we have seen so far” alarmed Maria Van Kerkhove of the WHO on March 19 at a press conference.
What is the BA.2 tariff in France?
The Omicron variant BA.2 is now more present than the BA.1 variant, which has been circulating mainly in France since the end of 2021. From April 7, according to Public Health France, BA.2 represents 92% Omicron sequences analyzed during the week of March 21-27. “The progression of BA.2 at the expense of BA.1 will continue to be monitored the entire metropolitan area, but at different levels depending on the region. In the DROMs, BA.2 also seems to be increasing, but the data need to be consolidated‘ adds the organization.
What are the symptoms of the BA.2 variant?
No specific symptoms are currently listed for subvariant BA.2 cases. On the other hand, for the Omicron variant “epidemiological studies point to a specific clinical picture more upper respiratory symptoms and less loss of taste and smell, and lower severity (up to 80% lower risk of hospitalization and ICU admission)” reported Santé Publique France on January 26. Symptoms of the BA.2 variant (like Omicron in general) can include:
- Cough ;
- Fever ;
- muscle pain or body aches;
- Sore throat ;
- Runny nose ;
- nausea and vomiting
- Uncomfortable breathing (less common)
- Loss of taste and smell (less common)
Is the BA.2 variant more contagious than Omicron?
“BA.2 is more transferrable than BA.1 (39% secondary attack rate for BA.2 versus 29% for BA.1). A study also estimates the generation interval (time between two events) of BA.2 is 15% lower than that of BA.1. These differences in transferability explain the rprogressive placement of BA.1 through BA.2 observed worldwide” stresses Public Health France on March 25. BA.2 “is the most contagious variant of the SARS-CoV-2 virus that we have seen so farsaid Maria Van Kerkhove, epidemiologist at WHO, on March 19.
What are the risks of reinfection with BA2?
The frequency of possible reinfections with SARS-CoV-2 has increased significantly since the introduction and spread of the Omicron variant in France in early December 2021, Public Health France notes.
“The resumption of the upward trend in the circulation of SARS-CoV-2 observed in France and the United States for several weeksCreation of the sub-line Omicron BA.2, Majority since week 09-2022 is two Factors that may play a role in the current trend of increasing numbers of reinfections” confirms the agency. Several recent studies have highlighted that Possibility of BA.2 reinfection occurring after BA.1 infection, even within a very short period of time (less than 60 days). “Nevertheless, they agree that these are likely rare occurrences.”
Is the BA.2 variant more dangerous than Omicron?
“Omicron’s BA2 subvariant ‘does not cause a more severe form’ of Covid than BA1, according to Maria Van Kerkhove, epidemiologist in charge of the emerging diseases unit at WHO, on March 19. However, with a large number of cases, you will see an increase in hospitalizations, which will lead to an increase in deaths.…”. She indicated that there are none not “Difference in severity between BA1 and BA2“.
“In France, the screening strategy can detect all omicrons regardless of whether it is BA.1 or BA.2, and therefore reactively knowing the edition size of the variant“indicates Public Health France. Second, sequencing makes it possible to distinguish between the subvariants BA.1 and BA.2 “Screening allows the omicron to be reactively followed as a whole, and sequencing allows finer analysis of the different sublineages [BA.1 ou BA.2]“.
Are vaccines effective against the BA.2 variant?
“The efficacy of the vaccine against symptomatic diseases caused by BA.1 and BA.2 is similar: after two doses the efficacy is 10% for BA.1 and 18% for BA.2, after three doses the efficacy is against symptomatic diseases 69% for BA.1 and 74% for BA.2 Efficacy decreases to almost 50% two and a half months after the 3rd dose for BA.1 and BA.2“according to the UK Health Authority’s study published on February 25.”This suggests Vaccination is at least as effective in preventing transmission of BA.2 and may be more effective in preventing transmission of BA.2 than BA.1‘ noted the WHO.’L‘the effectiveness of the vaccine against Omicron is maintained after administration of a booster dose, especially against heavy forms“confirmed Public Health France on January 26.
What treatments to prevent infection with the BA.2 variant?
Multiple treatments of monoclonal antibodies are available to prevent Covid-19 infection. Researchers from the Institut Pasteur, the CNRS, the Vaccine Research Institute (VRI) in collaboration with the CHR d’Orléans, the AP-HP, the KU Leuven (Catholic University of Leuven) and the Université Paris Cité studied theEfficacy of two combinations of monoclonal antibodies Therapies Ronapreve (combination of two antibodies developed by Roche/Regeneron) From where Evus hero (Combination of two antibodies developed by AstraZeneca) against the variant Omicron (BA.1 and BA.2) of the coronavirus. “We show that the antibodies and the corresponding sera are little or not active against BA.1, but are more active against BA.2. Compared to Delta, the neutralizing activity against BA.1 is more reduced: it takes 344 times more antibodies to neutralize BA.1 and 9 times more to neutralize BA.2” explains Timothée Bruel, first author of the study published on March 23 in Nature Medicine and researcher in the Virus and Immunity Unit at the Institut Pasteur (joint research unit of the CNRS). Among the 29 patients treated with antibodies, four omicron infections were described (including a severe case). “That suggests that in this case the treatment does not completely protect against infections or severe forms” explains Thierry Prazuck, co-lead author of the study and head of the department of infectious diseases at the CHR d’Orléans.
– “Serum neutralization of SARS-CoV-2 Omicron BA.1 and BA.2 sublines in patients receiving monoclonal antibodies,” Nature Medicine, March 23, 2022
– “SARS-CoV-2 variants of concern and variants being investigated in England”, British Health Agency, 25 February 2022
– “Coronavirus: spread of SARS-CoV-2 variants”, updated on February 25, 2022, Public Health France
-“BA.2 is more easily transmissible than BA.1, but vaccinated individuals are less likely to become infected and transmit the infection,” Jan. 31, Statens Serum Institut.
– COVID-19: Epidemiological update of January 27, 2022, Public Health France
– “Risk analysis on new variants of SARS-CoV-2”, 26 January 2022, Public Health France.
– “Now a variant of Omicron, BA.2, accounts for almost half of all Danish Omicron cases”, 20 January 2022, Statens Serum Institut.