NEW VARIANT. This variant of Omicron is the majority in France. 92% of the positive covid tests analyzed by Santé Publique France come from the BA.2 variant. What are its symptoms? What is its danger? Is it possible to be re-infected?
[Mis à jour le 8 avril 2022 à 11h13] BA.2 is a Omicron variantitself a variant of the Sars-CoV-2. BA.2 and responsible for the recent resumption of the epidemic. The underlining BA.2 is the majority in Francerepresentative 92% of positive covid tests analyzed by Santé Publique France according to the epidemiological point of April 7. He is more contagious than the BA1 Omicron sub-variant that first appeared in France. But he does not present no more danger. “We have past the peak of the epidemic rebound a few days ago. It’s been five days now that it’s downreassured Olivier Véran on Thursday, April 7 RTL. “I’m not saying the epidemic is behind us. I keep telling the French to protect themselves in the period. 150,000 contaminations a day is nothing“However, the Minister of Health has clarified. Several recent studies have highlighted the possibility of a reinfection by BA.2 following a BA.1 infection, including within a very short time (less than 60 days (2 months))). What is this new change of Covid-19? Is she more contagious, more dangerous, that Omicron? The vaccine is it effective against this new variant? What are the symptoms of BA.2 ? The point to date.
Definition: What is the new variant BA.2?
“BA.2 is a Omicron variant. It’s a “little cousin” of the Omicron variant“explained Jean – François Delfraissy, president of the Covid Scientific Council, to the microphone of Franceinfo in January. Named BA.2, it is a sub-lineage of Omicron like BA.1 (which used to run) or BA.3. “The genetic sequence of sub-variant BA.2 differs BA.1 and in particular has differences in amino acids in Spike protein and other proteins. “ indicated theWHO in February 2022. “The latest data seem to confirm that BA.1 and BA.2 have similar severity and immune response, so BA.2 is not considered a separate variant but is included in the Omicron VOC. “ says Public Health France. However BA.2 “is the varying the most contagious du virus SARS-CoV-2 that we have seen so farMaria Van Kerkhove of the WHO warned in a press conference on March 19.
What is the rate of the BA.2 variant in France?
The BA.2 Omicron variant is now more present than the BA.1 variant, which has been in the majority in France since the end of 2021. As of April 7, according to Public Health France, BA.2 represents 92% Omicron sequences analyzed for the week of March 21-27. “The progression of BA.2 to the detriment of BA.1 is observed on the entire metropolitan area, but at different levels depending on the region. In DROMs, BA.2 also seems to be on the rise but data needs to be consolidated“adds the body.
What are the symptoms of variant BA.2?
At present, there are no specific symptoms identified in cases ofvariants BA.2. On the other hand, for the Omicron variant “epidemiological investigations indicate a specific clinical presentation with more upper respiratory symptoms et less loss of taste and smell, as well as lower severity (up to 80% lower risk of hospitalization and intensive care admission)“reported Public Health France on January 26th. Symptoms of variant BA.2 (such as Omicron in general) may be:
- Muscle aches or aches and pains;
- Sore throat;
- Nasal discharge;
- Nausea and vomiting
- Unpleasant breathing (less common)
- Loss of taste and smell (rarely)
Is the BA.2 variant more contagious than Omicron?
“BA.2 is more transmissible than BA.1 (secondary attack rate of 39% for BA.2 versus 29% for BA.1). One study also estimates that the generation interval (delay between two cases) of BA.2 is 15% lower than that of BA.1. These differences in transmissibility explain the rprogressive location of BA.1 by BA.2 observed worldwide“emphasizes Public Health France on March 25. BA.2 “is the varying the most contagious of the SARS-CoV-2 virus we have seen so far“said Maria Van Kerkhove, an epidemiologist at the WHO, on March 19.
What are the risks of BA2 reinfection?
The frequency of possible reinfections with SARS-CoV-2 has increased significantly since the introduction and dissemination in France of the Omicron variant in early December 2021, according to Santé Publique France. “The resurgence of SARS-CoV-2 traffic in France for several weeksemergence of Omicron BA.2 underlining, majority since the week 09-2022 are two factors that may play a role in the current trend of increasing number of reinfections “ confirms the agency. Several recent studies have highlighted the possibility of BA.2 reinfection following a BA.1 infection, even within a very short time (less than 60 days)). “Nevertheless, they agree that these are likely to be rare events.”
Is the BA.2 variant more dangerous than Omicron?
“The Omicron BA2 variant does not “cause more severe form” of Covid than BA1, according to Maria Van Kerkhove, an epidemiologist in charge of the Emerging Diseases Unit at the WHO, on March 19. However, with a large number of cases, you will see an increase in hospitalizations and this will turn into an increase in deaths... “. She clarified that there is not “difference in severity between BA1 and BA2“.
“In France, the screening strategy detects all Omicrons regardless of whether they are BA.1 or BA.2 and therefore to know reactively the level of circulation of the variant“indicates Public Health France. In a second step, sequencing makes it possible to differentiate between sub-variants, BA.1 and BA.2 “Screening allows reactive tracking of Omicrons as a whole, and sequencing allows for finer analysis of different sub-lineages. [BA.1 ou BA.2]“.
Are vaccines effective against variant BA.2?
“The effectiveness of the vaccine against symptomatic disease caused by BA.1 and BA.2 is similar: after two doses the effectiveness is 10% for BA.1 and 18% for BA.2, after three doses the effectiveness against symptomatic disease is 69% for BA.1 and 74% for BA.2 The efficacy drops to almost 50% two and a half months after the 3rd dose for BA.1 and BA.2“According to the study by the British Health Agency published on February 25.”This suggests that vaccination is at least as effective in preventing the acquisition of BA.2 and may be more effective in preventing the transmission of BA.2 than in BA.1“remarked the WHO.”L‘vaccine efficacy is maintained against Omicron after a booster dose, especially against severe forms“confirmed Public Health France on January 26.
– “SARS-CoV-2 variants of concern and variants under investigation in England”, British Health Agency, 25 February 2022
– “Coronavirus: circulation of SARS-CoV-2 variants”, updated on February 25, 2022, Public Health France
– “BA.2 is more transmissible than BA.1 but vaccinated people are less likely to become infected and transmit the infection,” Jan. 31, Statens Serum Institute.
– COVID-19: epidemiological point of January 27, 2022, Public Health France
– “Risk analysis on emerging variants of SARS-CoV-2”, January 26, 2022, Public Health France.
– “Now a variant of Omicron, BA.2, accounts for almost half of all Danish Omicron cases” January 20, 2022, Statens Serum Institute.