At least since the emergence of the omicron wave, it has been clear: you can have the crown despite vaccination and quite often several times. But is this the normal course of events with a virus affecting the respiratory system and not a cause for concern because the infection is becoming more harmless as some experts believe? Or is the growing risk of reinfection a cause for concern?
The second opinion is now supported by an as yet unexamined study, in which researchers looked at the risk of various secondary diseases, depending on how often those affected were infected with Sars-CoV-2. The result of the investigation was clear: the risk of suffering heart and lung damage or prolonging the symptoms of Covid as fatigue increases with each further infection.
Covie-19: About 12% of people tested had already been infected twice
The team led by Ziyad Al-Aly of Washington University evaluated data from the US Army Veterans Health Insurance Company. According to the authors, this is the largest healthcare system in the United States. However, 90 percent of the policyholders in the data sets are men and women are therefore clearly under-represented.
Scientists finally filtered out 257,427 people who had a confirmed corona infection. Of these, 36,417 (12%) had had Covid-19 twice, 2,263 (0.76%) three times, and 246 (0.08%) four or more times. Then the researchers looked at the number of different complications in the six months following diagnosis and compared them to their incidence in a group of 5.4 million uninfected people.
People infected more than once have double the risk of death from all causes
Compared to those infected only once, the overall risk of death doubled and affected about 23.8 out of 1,000 people in the infected group at least twice. The risk of being hospitalized tripled (95.5 people per 1,000). Damage to the respiratory organs or cardiovascular system was twice as common among reinfected, as were diagnoses of diabetes or fatigue, mental problems, digestive disorders, or other Long Covid symptoms.
These problems occurred most severely during the acute phase of the disease. In many cases, however, they were still detectable six months after reinfection. The risk increased with each reinfection. “There was a gradual association, which means that the risk of adverse health outcomes increased with the number of infections,” the authors write.
The long-term risks of Covid also increase with reinfections in vaccinated people
According to the authors, however, vaccination cannot reduce the risk of secondary diseases in case of reinfection. The growing risk has been found in unvaccinated, vaccinated and even augmented people.