For several years now, December has no longer only been the month of Christmas celebrations or the approach of the New Year, but also the anniversary of the starting point of what shook the entire Earth for very long months: the first case of Covid-19 detected in China, in Wuhan.
With the peak of the epidemic further and further behind us, the year 2023 marked a new stage in the normalization of Covid, which has become almost commonplace. Since May, the World Health Organization (WHO) has no longer considered Covid to be an international emergency. If the WHO is careful to repeat that the pandemic continues, this decision is a considerable symbol. The year also saw the end of “zero Covid” with China being the last major country to renounce applying this exceptional policy aimed at eliminating the circulation of the disease and not just limiting it.
Declining lethality
Why this standardization? Firstly because a Covid infection appears today much less dangerous than in 2020, when many countries decreed unprecedented confinements in the face of the deadly effects of SARS-CoV-2, the virus at the origin of the epidemic. This is the consequence of effective vaccines, distributed since 2021, and of the immunity acquired by populations over successive waves of virus infections.
Lethality, which corresponds to the individual risk of dying after an infection, “has fallen significantly compared to the pre-vaccination era”, underlines to AFP Antoine Flahault, epidemiologist at the University of Geneva. “It’s around one in a thousand or maybe even less”, when the risk was measured as a percentage at the start of the pandemic, he emphasizes. This is a level comparable to an infection with the seasonal flu virus, even if it is risky to precisely designate the more dangerous of the two.
“Covid-19 is one of the diseases that is progressing at the moment”
Covid therefore seems to have become one respiratory disease among others. But it continues to pose, in this context, major public health problems linked to its particularities. Unlike other diseases such as the flu, Covid experiences several waves per year. It can therefore hardly be described as a winter disease, but an outbreak can coincide with the classic epidemic season.
This is currently the case: “Covid-19 is one of the diseases that are progressing at the moment” in many countries, Maria Van Kerkhove, epidemiologist at the WHO, warned on Sunday. This growth is partly linked to the emergence of a sub-variant, known as JN.1. New version of Omicron, dominant version of the virus for two years, it does not appear particularly dangerous but seems very transmissible.
36,895 new cases from December 11 to 17
This is still the great particularity of Covid compared to other infections such as the flu: it remains very contagious even today. In its last weekly bulletin of December 20, Public Health France has once again warned of “an ever-increasing level of circulation of SARS-CoV-2”. 36,895 new cases were detected from December 11 to 17, figures which climb from week to week.
“Over a year, there are 5% to 10% of people who catch the flu”, but much more for Covid, points out Antoine Flahault, emphasizing that this automatically causes mortality to jump at the population level, even if individual risk is limited.
The precise number of deaths, however, remains unclear because many deaths are linked to the disease without being immediately attributable to it. The annual study by Public Health France in collaboration with Inserm on the causes of mortality in France in 2021 thus highlighted an increase in deaths linked to cardiovascular diseases or of nutritional origin, which “could be linked to effects indirect effects of the Covid-19 epidemic.
Official WHO figures suggest some seven million deaths since the start of the epidemic four years ago, but the organization itself admits that the real level is probably around 20 million, or more.
The fear of long Covid
Beyond mortality, there also remains the question of lasting after-effects, called “long Covid”: fatigue, breathing difficulties… The reality of these symptoms is no longer in doubt today, as is their physiological and not psychological origin. . However, it remains difficult to establish their frequency and whether Covid causes them more often than other diseases. The after-effects of the flu, for example, “have not been the subject of the same spotlight”, underlines epidemiologist Antoine Flahault.
However, several studies published this year are rather reassuring in denying the idea of an explosion in long-term Covid cases over time. Conducted among the Swedish population, a study published in September in the Journal of Infectious Diseases thus demonstrates a “lower risk” after an Omicron infection, compared to previous variants.