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, faced with a wide range of effects of this new virus, where everything had to be discovered. But how long is a long Covid? 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 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 pollution.
“The vast majority of patients will feel well after a year”
In practice, a long Covid results in symptoms persisting or new ones appearing more than four weeks after a first infection. And “according to a previous study published last year on the long Covid and the consequences of the virus, more than a third of patients after more than a year still suffered from symptoms associated with Covid-19”, recalls Dr. Benjamin Davido, infectious disease specialist and Covid-19 emergency physician at the Raymond-Poincaré hospital in Garches (Hauts-de-Seine).
And patients suffering from prolonged Covid, the infectious disease doctor received many at the beginning of the pandemic. “The first consultations in 2020 for persistent symptoms concerned patients who could not be tested because screening was not available to everyone at the beginning of the pandemic, he recalls. We received patients who were concerned about experiencing symptoms after six weeks, and who were concerned. Patients reviewed regularly, and “at six months a certain number were better, after a year, overall, they were cured or with residual symptoms,” confirms the infectious disease doctor.
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 the symptoms might last. “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 prolonged 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. , which reviewed the electronic medical 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 earlier 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 is quite logical”.
Thus, in consultation, “we are still less encouraged by this long covid problem since the arrival of Omicron. And probably also, as this new study shows, because a number of cases originating from the beginning of the pandemic, in the end recovered from these persistent symptoms. Even though there is certainly 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 is not only Omicron that explains this phenomenon. The results also show that “vaccinated people were less exposed to the risk of respiratory distress – the most common effect observed in cases of mild disease – than non-vaccinated people”, specify the authors of the study.
“It has been proven: Vaccination reduces the probability of being infected by up to 45% and will reduce the risk of long-term Covid by 30%, which is very positive, welcomes Dr. Davido. The vaccine would even have a curative effect 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 that is stuck in the cells, and relieve 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 a rise in contamination and another explosion in long Covid cases? “The current Chinese scenario, with a colossal number of contaminations in 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 that did not make a vaccine recall and that loses its immunity. Mathematically, this would generate new cases of prolonged Covid. We tend to forget the advantage 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 take months or even more”.
By September, at least 17 million people in Europe had suffered from prolonged Covid in the first two years of the pandemic, according to World Health Organization models.