- What are the symptoms of Omicron?
- What is the incubation time of Omicron?
- What is the reinfection timeframe?
- Variant BA 5: is it dangerous? Should we be worried?
- After infection with Omicron, what immunity?
The Covid epidemic (9th wave) has stabilized and the epidemic continues to slow down according to the latest report from Public Health France as of December 23. This is the Omicron variant, and more precisely the BQ.1.1 (subvariant of BA.5) which currently represents two-thirds of contamination.
In France, it is the BQ.1.1 (sub variant of BA.5, itself a variant of Omicron) which continues to progress: according to Public Health France, it accounted for 62% of footage in the November 28 Flash survey. Another variant, predominant in the State of New York (USA) circulates in France, but at a very low level.
In view of the triple Covid / Flu / Bronchiolitis epidemic, respect for barrier gestures (mask, hand washing, ventilation) and sanitary measures (tests, isolation) are still essential today. Moreover, there is still time to get vaccinated with the effective bivalent booster against Omicron.
The basics of the Omicron sub-variant, the BA.5, which is currently the majority in France:
- BA.5 is more contagious than BA.2 (January wave), which was itself more contagious than BA.1 and even more than Delta (variant 2021).
- THE incubation time (time to onset of symptoms) is a bit shorter: 3 days.
- BA.5 sometimes (but not always) gives rise to more marked symptomssometimes with digestive symptoms and loss of taste and smell.
- With BA.5 duration of symptoms is longer (on average 7 days versus 4 days for BA.1).
- Asymptomatic forms are less numerous.
What are the symptoms of BA.5?
THE symptoms the main ones of the Covid are fever or feeling feverish (asthenia) and cough. There are no new symptoms with BA.5, the symptoms remain “classic”.
There sudden loss of sense of smellwithout nasal obstruction and total disappearance of taste are also symptoms of Covid.
According to a study conducted last June by Public Health France out of 300 Covid cases infected with BA.5,
>> The asymptomatic forms are less numerous with BA.5 than with the BA.1 (only 3% versus 11%).
>> LSymptoms of infection seem a bit more intense than those observed with BA.1 and BA.2: more fever, fatigue and digestive disorders. Runny nose and sore throat were also more frequent.
What are the symptoms of the new Omicron variant (BA.5) in adults ? Here are the symptoms reported according to this data provided by Public Health France as of June 17:
- Asthenia (fatigue) in 72% of cases
- Cough (56% of cases)
- Fever (56% of cases)
- Runny nose (49% of cases)
- Headaches (headaches) (50% of cases)
- Myalgia (or body aches) in 39% of cases
- Sore throat (38% of cases)
- Feeling of fever (17% of cases)
- Nausea and vomiting (17% of cases)
- Loss of taste or dysgeusia (16% of cases)
- Loss of smell (16% of cases)
- Shortness of breath (14% of cases)
- Diarrhea (14.5% of cases)
- Dyspnea (unpleasant breathing) in 7.3% of cases.
>> The range of symptoms was wider: the likelihood of presenting with anosmia (loss of smell) and ageusia (loss of taste), but also nausea and vomiting or even digestive disorders such as diarrhea are higher for cases of BA.4/BA.5 compared to those of BA.1, according to this same study by Santé Publique France.
Furthermore, theodynophagiaspecific to Omicron, which is manifested by pain in the esophagus when swallowing of solid or liquid food, seemed to be a frequent symptom. Already identified during the January wave, this symptom would particularly affect young and vaccinated patients, without risk factors. In any case, this is what was observed by a Swedish study in January 2022. Most patients also had inflammation of the throat, such as laryngitis or pharyngitis, which is quite logical.
>> Finally, patients infected with the new BA.5 variant had declared a longer duration of symptoms: on average 7 days versus 4 days.
“A new symptom seems to affect the sick, explained in June at FigaroGilles Pialoux, Head of the Infectious and Tropical Diseases Department at Tenon Hospital in Paris. They are often sore throat and trouble swallowing“. Another constant drawn up by this specialist: there are fewer asymptomatic people. Finally, “ISymptoms last longer and are stronger“.
Good news though, “the lungs are not attacked as with the Delta“moderated the infectiologist.
Jacques Battistoni, president of the generalist union MG France, interviewed by Le Parisien (edition of June 22) had confirmed these “more marked” symptoms with “fairly intense and prolonged fevers”. For his part, the secretary general of SOS Médecins, Serge Smadja, also questioned by our colleagues from Parisian, rather had the feeling that patients were dragging the virus around for eight days, instead of four in January.
In January, another “new” symptom was observed in children : a rash sudden, called “rash”. Then in early March, American doctors communicated on “Croup”, which is similar to laryngitis.
Read also:
- Covid-19: what are the symptoms according to the doses of vaccine you have received?
- How to make the difference between Covid and the flu ?
- How to tell the difference between the Covid and a cold ?
- How to take care of yourself at home?
What is the incubation time of Omicron?
The more the Covid virus evolves, the more it acquires transmission faculties. In other words, successive variants are always more contagious than those that preceded them.
An important element of the new Omicron variant accelerates its circulation: its time incubation (the time between contamination and the appearance of symptoms) is shorter, of the order of three days instead of four to five with the Delta variant.
The interval between the onset of symptoms in an infected person and their appearance in a contact case can therefore be between 3 days and 5 days.
How long are you contagious? People who are infected are more likely to transmit the virus in the 48 hours preceding the onset of symptoms and in the first days of the symptomatic period. Contagiousness gradually decreases in the days following the onset of symptoms.
What is the reinfection timeframe?
There is an increased risk of reinfection with the BA.5 subvariant.
Note: we speak of reinfection when we present two positive tests at least 60 days apart.
Since December 2021, reinfections are “frequent”as pointed out Public Health Francein an article published on September 15, 2022. This proportion is increasing sharply: it was 0.7% until December 5, 2021 and 6.7% since December 6, 2021. In mid-August, they represented even 18% of Covid cases.
The reason for this increase? It is the arrival of the Omicron variant, much more transmissible and above all capable of escaping the immunity developed by the organism after a first infection.
Another reason is that the cumulative effect of vaccine injections and infections is no longer optimal. And for good reason : the vaccines were designed two years ago, based on the Wuhan strain. The new 2022 fall vaccination campaign provides new bivalent vaccines, adapted to circulating strains.
- Pfizer’s bivalent vaccine targeting Omicron
- Moderna’s bivalent vaccine targeting Omicron
Variant BA 5: is it dangerous? Should we be worried?
Good news, according to a Public Health France study on more than 300 cases of contamination by BA.4 and BA.5, the hospitalization rate was not significantly higher for BA.4 and BA.5 compared to BA.1 and the majority of hospitalized cases had risk factors.
That said, the health authorities advise the most fragile (under 60 with comorbidities, over 60 with or without comorbidities, immunocompromised and those around immunocompromised people) to get their booster shot and of wear a mask in public places and maintain barrier gestures (hand hygiene, ventilation).
Since the discovery of the Omicron variant, international scientific data suggest less severity of infection by the Omicron variant, but also reduced risk of hospitalization for Omicron compared to other variants.
However, the oldest and most fragile remain vulnerable. Indeed, the number of cumulative deaths between 1er January and May 31, 2022 (so before the BA.5 rebound) is chilling, with approximately 25,000 deaths related to COVID-19 according to Public Health France (by comparison the flu causes between 7,000 and 10,000 deaths each year). Besides, the proportion of people over 85 among the deceased has increased significantly : in hospital, it went from 43% in March-May 2020 (first wave) to 83% in January-March 2022. “They are the ones who are dying the most from Covid today”,underlined Arnaud Fontanet, member of the Scientific Council, during a press briefing on July 21.
After infection with Omicron, what immunity?
According to scientists, even if there will be periods of epidemic rebound in the future, we could be more and more immunized, and this, despite the appearance of new variants. Indeed, theimmunity conferred by successive vaccines and variants would allow us to acquire a increasingly effective immunity (we speak of cell-mediated immunity).
“When we encounter another variant, this immunity prevents us from having serious forms, it’s rather positive because whatever new variant emerges, over time we will have more chance of being protected from serious forms”, explains the epidemiologist and professor of public health at the University of Geneva, Antoine Flahaut.
“You have to think of immunity as successive layers of paint. Thanks to regular doses of vaccine, the majority of us are now protected against severe infections and even death. The good news with Omicron is that An ordinary infection by this less aggressive variant generates another type of immunity than vaccine immunity. This form of immunity could protect us against future infections, like the nasal vaccine that we are all waiting for”, details the Swiss epidemiologist, Didier Pittet.
- Read also: Covid-19: having been infected with Omicron in early 2022 (in addition to being vaccinated) would protect against new variants
Sources:
- Variant risk analysis, Public Health France, June 15, 2022.
- UK Health Security Agency
- FDA
- Omicron variant more resistant to vaccine but causes less severe covid, major South African study concludes, washington postDecember 14, 2021.
- European Center for Disease Prevention and Control.
- Update, Omicron Variant, WHONovember 28, 2021.
- Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern, WHO, November 26, 2021.