The symptoms of long Covid would not persist beyond a year after developing a mild form of the virus, according to a study published this Thursday in the
British medical journal
.
For researchers, anti-covid vaccination would have a protective effect against long Covid.
Also, Omicron and its subvariants are said to cause fewer long forms of the disease.
Since the start of the pandemic, millions around the world have described persistent symptoms after contamination with Covid-19.
To the amazement of doctors and scientists, confronted with a wide range of effects of this new virus on which everything was to be discovered.
But a long Covid, how long is it?
A few weeks, a few months, or more?
Three years after the discovery of the coronavirus, scientists are beginning to have enough perspective to get an idea.
According to a study published this Thursday in the British Medical Journal (BMJ), "most symptoms or conditions that develop after mild Covid-19 infection persist for several months, but return to normal within a year. » according to the contamination.
“The vast majority of patients will be fine after one year”
In practice, a long Covid results in the persistence of symptoms or the appearance of new ones, more than four weeks after an initial infection.
And “according to a previous study published last year on the long Covid and the sequelae of the virus, at more than a year, more than a third of the patients still suffered from symptoms linked to Covid-19”, recalls Dr Benjamin Davido, infectious disease specialist and Covid-19 crisis doctor at the Raymond-Poincaré hospital in Garches (Hauts-de-Seine).
And patients suffering from long Covid, the infectiologist received many at the start of the pandemic.
“The first consultations in 2020 for persistent symptoms concerned patients who could not be tested because screening was not accessible to everyone at the start of the pandemic, he recalls.
We received patients worried about experiencing symptoms beyond six weeks and who were worried.
Patients reviewed regularly and “at six months, a certain number were better, at one year, overall, they were cured or with residual symptoms”, confirms the infectiologist.
Maytal Bivas-Benita, a researcher at Israel's KI Research Institute and co-author of the study, said she was "encouraged" by the results, amid fears about how long symptoms might persist.
"The vast majority of patients will be fine after a year, and I think that's good news," she said.
Fewer long Covids with Omicron
"These results suggest that, although the phenomenon of long Covid has been feared and discussed since the beginning of the pandemic, the vast majority of cases of mild infection do not suffer from severe or chronic symptoms in the long term", explain the researchers. , who sifted through the electronic records database of Israel's second-largest health insurance fund, Maccabi Healthcare Services, whose nearly two million members were tested for Covid-19 between March 1, 2020 and September 1, 2020. October 1, 2021.
In addition, “with the new variants and sub-variants of the Omicron era, long Covids are half as present as with the previous strains, according to most prevalence studies, notes Dr. Davido.
Probably because Omicron initially generates forms that are often less symptomatic, or even asymptomatic, so it's quite logical”.
Thus, in consultation, “we are still less solicited by this long covid problem since the arrival of Omicron.
And probably also, as this new study demonstrates, because a number of cases dating from the start of the pandemic eventually recovered from these persistent symptoms.
Even if there certainly remains a hard core of extremely sick people at a distance from their infection.
On the other hand, we no longer have this influx of patients with a long Covid since Omicron ”.
The protective effect of vaccination
But it's not just Omicron that explains this phenomenon.
The results also show that “vaccinated people were less exposed to the risk of breathing difficulties – the most common effect observed in cases of mild illness – than non-vaccinated people”, specify the authors of the study.
“It has been demonstrated: vaccination reduces the probability of becoming infected by up to 45%, and would reduce the risk of long Covid by 30%, which is very positive, welcomes Dr Davido.
The vaccine would even have a curative action in certain cases: it is estimated that vaccination, by stimulating the production of neutralizing antibodies at very high levels, allows the clearance of the Spike protein”.
In short: it would allow the body to develop the capacity to eliminate the virus lodged in the cells, ridding the patient of his persistent symptoms.
Uncertain times ahead
So, with a vaccine recall rate in free fall in France, should we fear a flashback with an increase in contamination and a new explosion in long Covid cases?
“The current Chinese scenario, with a colossal number of contaminations within a poorly vaccinated population, increases the risk of seeing a new variant appear, fears Dr. Davido.
And there, the risk in cascade, it is a new very strong wave in France, in a population which did not make a vaccine recall and which loses its immunity.
Mathematically, this would generate new cases of long Covid.
We tend to forget the benefit of the vaccine: since its arrival, the face of the pandemic in France is no longer the same.
However, no one wants to repay the burden of a long form that can last months or even more”.
By September, at least 17 million people in Europe had suffered from long-lasting Covid in the first two years of the pandemic, according to models from the World Health Organization.
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