Variant BA.5 Covid: France, symptoms, duration, contagion

Variant BA.5 Covid: France, symptoms, duration, contagion

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BA.5, a sub-variant of the Omicron variant, is predominant in France but its circulation decreases in August. Among the clinical signs: fatigue, vomiting and sore throat. The duration of the signs can be up to 7 days. Symptoms, duration, contagion, treatments… All about the covid BA.5 variant

The initial virus of the Covid-19 disease, Sars-Cov-2, mutated several times to the variant Omicron which began to arrive at the end of 2021 in France. Now ubiquitous, this variant has five sublineages of which the BA.5. It has been the majority in France for several weeks reports Public Health France in his last point. The symptoms the most common are the fatigue, cough, fever, headache and sore throat. Vomiting, diarrhea and night sweats are equally reported. This BA5 variant is “very transmissible but not more severe” recalled the president of the Covid Scientific Council on July 11 on France Inter. The people positive and vaccinated must isolate themselves 7 days or 5 days in the event of a negative test on day n°5 and in the absence of symptoms for 48 hours on day n°5.

What is the BA.5 variant?

BA.5 is a sublineage of the Omicron variant of Covid-19. It began to be identified in January and February 2022 in South Africa according to ECDC; early April according to Public Health France. It aired at Portugalleading to a new wave of Covid-19 in May, which is particularly virulent for the over 80s. He is particularly watched because he has L452 mutation (like the BA.4) associated with the increased transmissibility of Delta.

What are the symptoms of the BA.5 variant?

According to Santé Publique France, the most frequent clinical signs in the event of infection with the BA.4 and BA.5 variants are fatigue, cough, fever and headache. Furthermore, “the probability of present anosmia [perte d’odorat] and ageusia [perte du goût]but also nausea, vomiting and diarrhea is higher for BA.4/BA.5″ cases says the health agency. AInstead of lasting an average of 4 days, they last rather 7 days or even 10 days so we contaminate longer“explained Dr. Damien Mascret on June 27. A new symptom is reported by Professor Luke O’Neill of Trinity College Dublin (Ireland): night sweats : “The disease is different because the virus has changed, night sweats being a new symptom“said the immunologist on Irish radio Newstalk on July 7.

Age and symptoms of BA.4 and BA.5 cases compared to BA.1 cases as of June 15 © Public Health France
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How long do symptoms of the BA5 variant last?

The duration of clinical signs is on average 7 days for the cases of BA.4 and BA.5 versus 4 days for other Omicron cases.

What is the rate of the BA.5 variant in France?

Within the Omicron variant, the gradual replacement of the BA.2 sublineage by BA.5 continues and the latter has become majority in metropolitan France since June 13, 2022. BA.5 accounted for 92% of screens analyzed by Public Health France in the Flash survey of July 11 (compared to 3.6% for BA.2 which it replaced). As for BA.4, it was detected in 6.2% of the sequences.

Sublineages of the Omicron variant during Flash surveys July 2022
Omicron variant sublineages during Flash surveys July 18, 2022 © Public Health France

Is the BA.5 variant more contagious?

The BA5 is more contagious than BA2. Considering the fact that it is more contagious, it escapes post-vaccination immunity a little better so we will probably continue to see this resurgence of new cases in the coming weeks“, explained Yves Buisson, president of the Covid cell of the Academy of Medicine on Europe on June 7. The symptoms last longer (7-10 days)”so we contaminate longer“explained Dr. Damien Mascret June 27. The Omicron BA.4 and BA.5 sub-lines replaced the BA.2 and resulted in a new epidemic wave in South Africa (5th wave). Same thing for the BA.5 exclusively in Portugal (with a heavier epidemiological impact on the over 80s).

In South Africa : the BA.4 growth rate is +8% per day compared to BA2; +12% for BA.5.

In Portugal :BA.5 was associated with an epidemic resumption but the peak of this wave which started at the end of April now seems to have passed. If this is confirmed, the amplitude of the wave will have been much less than the previous one.” informed Public Health France on June 15.

Is the BA.5 variant more dangerous?

Data accumulated in several countries did not observe an increase in severity associated with BA.4 and BA.5. A first study from South Africa comparing the risk of serious events between the Omicron BA.1 wave and the BA.4/BA.5 wave showed similar risks of hospitalization or death between waves BA.1 and BA.4/BA.5reports Public Health France on July 6. These two Omicron waves were associated with lower risks compared to previous waves. The risk of hospitalization/death was less in previously infected cases (70% lower) or vaccinated 3 doses (83% lower) compared to uninfected/vaccinated cases. “The median length of hospitalization (for BA4 or BA5 cases, editor’s note) is 5 days“indicated Public Health France on June 15.

Are vaccines effective against the BA.5 variant?

Preliminary data from the UK found only no significant difference in vaccine efficacy for BA.4 and BA.5 compared to BA.2, reported Santé Publique France in the July 6 variant risk analysis. Analysis of the BA.4/BA.5 wave in South Africa observed a hospitalization rate similar to that of the BA.1 wave. “These data support a vaccine efficacy and of comparable severity for BA.4 and BA.5 compared to previous Omicron sub-lines” estimates Public Health France.

What treatments are effective if you are contaminated with the BA.5 variant?

The Paxlovid remains the first-line curative treatment regardless of the variant or sub-variant of SARS-CoV2. “Its activity is not modified vis-à-vis BA.4 and BA.5 compared to the BA.1 and BA.2 sub-variants” confirms the Directorate General of Health on July 11. This antiviral is administered orally. It can be prescribed by any doctor, and has been available in health establishments and in community pharmacies since February 2, 2022. In the event of contraindications to Paxlovid (in particular related to drug interactions), the treatment Evusheld (tixagevimab 150 mg/cilgavimab 150 mg) is available. It is administered in healthcare facilities by the intramuscular route.

What are the differences between the BA.5 variant and the BA.2 variant?

BA.4, BA.5 spread better than BA.2. This one (BA5, editor’s note) escapes the vaccine a little better. And it shows the evolutionary capacity of the virus which is able to evade vaccines, at the same time as increasing its transmission. But we also know that symptoms are not more severe“said epidemiologist Anne-Claude Crémieux on June 22 on FranceInfo. “These two sub-lineages are quite similar to BA.2 but their Spike protein also has the mutations L452R/F486V and the R493Q reversion. BA.4 and BA.5 soon replaced BA.2 in South Africa. BA.4 and BA.5“reported Public Health France on May 18. The mutation L452R, which was also found on the Delta variant, continues to increase in positive Covid tests in France. L’Median age of cases investigated in France is 47 years old, higher than that of BA.1 infection cases (35 years).

Sources:

– Risk analysis on emerging variants of SARS-CoV-2 carried out jointly by Public Health France and the CNR for respiratory infection viruses, July 6, 2022.

– Risk analysis on emerging variants of SARS-CoV-2 carried out jointly by Public Health France and the CNR for respiratory infection viruses, June 15, 2022.

– Epidemiological update: SARS-CoV-2 Omicron sublines BA.4 and BA.5, ECDC, May 13, 2022

– Epidemiological Bulletin, Public Health France

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