Is re-infection with coronavirus more severe than the initial infection?

This end of the year 2020 gives an impression of déjà vu. THE’epidemic coronavirus is spreading again across Europe as the holidays approach and restrictive measures are increasing in neighboring countries. There are about 18,000 confirmed infections per day (average calculated over seven days) in France, and an infected person infects 1.44 people on average. Each wave of the epidemic brings with it an extremely rare phenomenon, but which does exist, re-infections. A person already infected with the coronavirus is not safe from catching it again. Qatari scientist studied reinfection in her country, and in particular the evolution of the symptoms of Covid-19 in this territory. Is reinfection associated with a more severe Covid-19 ?

Milder forms of Covid-19 after second infection

First, a reinfection is defined by a PCR test positive 90 days after primary infection. During the study period, 1,304 cases of reinfection were identified in Qatar. The symptoms of these people were compared with those of first-time infected people of the same sex, age and nationality. People who are re-infected are 90% less likely to be hospitalized or die than people who are infected for the first time. No death or hospitalization were observed in the group of re-infected. They have developed a mild form of Covid-19.

The result is not surprising. The initial infection and immunity resulting protection solid against infection and symptomatic forms. The duration of this protection remains to be defined, but the median duration between the first and the second infection in the people studied here is 277 days, or 9 months. These re-infections took place in 2020 when the Delta variant was not present in Qatar.