Published on
Updated
Reading 2 mins.
in collaboration with
Dr Gérald Kierzek (Medical Director)
According to an American study, reinfection with SARS-CoV-2 would double the risk of death and triple the risk of hospitalization and heart problems. Should we be afraid of it?
With the arrival of Omicron in 2021, which is more contagious, many French people, even vaccinated, have contracted covid once, twice or even more since the start of the pandemic. Banal reinfections, without too much damage for many but which would not however be trivial if we are to believe an American study published on November 10 in Nature Medicine.
Sequelae and complications identified in people infected twice (or more)
The research was based on medical data of 5.8 million people from the US Department of Veterans Affairs, the largest nationally integrated health care delivery system in the United States. In these data, 443,588 people with a first infection between March 2020 and April 2022, and 40,947 people had a reinfection. The team then carried out analyzes to examine the risks of all-cause mortality, hospitalization and a set of predefined outcomes in people who had a reinfection compared to those who did not have a reinfection up to 180 days later.
According to this analysis, a constant emerges: “The risks of developing health problems were lowest in people with one infection, but increased in people with two infections and were highest in people with three or more infections”. For the team, reinfection contributed to additional risks of death, hospitalization and pulmonary sequelae, cardiovascular disorders, hematological, diabetic, renal, musculoskeletal and neurological disorders.
However, it is difficult to interpret these data
The study, which has the merit of looking at the risks induced by several Covid-19 infections, does not however provide a universal and safe answer, and must be taken with a grain of salt.
First of all, because the counted cases of reinfection were known only by positive diagnostic tests. Infections could have passed under the radar on the side of the control group, if they were not tested, distorting the compared data. Additionally, and most importantly, the data is all from older, white men, who may experience the complications discussed with or without covid.
A precaution to take into account shared by Dr. Gérald Kierzek, medical director of Doctissimo who also sees a selection bias: infected and reinfected people are by nature people with a weaker immune system too.
“This is also called a syndemic (an interlacing of diseases according to the definition). Covid can be an aggravating factor for other pathologies, but it is also because they have other health problems that these subjects can be reinfected” he explains. Finally, it is difficult to know precisely if the covid is here the cause or the consequence of a degraded state of health. “The two are two are probably intertwined.” he concludes.