No super immunity
Reinfections with the coronavirus increase the risk of death
By Solveig Bach
After recovering from the corona infection, many people feel as if nothing could happen to them. But the idea of superimmunity is not only delusional, but also wrong, as an American study shows.
While fewer and fewer people have never had a coronavirus infection, the number of people who have been infected with the virus for a second or even third time is increasing. A new study from the US shows that these re-infections often have serious health consequences.
Researchers from the Washington University School of Medicine in St. Louis and Veterans Affairs St. Louis Health Care System found that repeated Sars-CoV-2 infections increase the risk of health damage in multiple organ systems. These include hospitalizations, lung, heart, brain, blood, musculoskeletal and digestive tract disease, and even death. Reinfection also contributes to diabetes, kidney disease, and mental problems. The results were published in “Nature Medicine”.
About 5.8 million anonymized medical records in a database maintained by the US Department of Veterans Affairs, the largest integrated healthcare system in the United States, were analyzed for the study. Patients represented multiple age groups, ethnicities, and genders.
This included 5.3 million people who did not test positive for the corona infection from March 1, 2020, to April 6, 2022. During the same period, the researchers also compiled a control group of more than 443,000 people who tested positive, as well as another group of nearly 41,000 people who had two or more documented infections. Of the second group, most people had two or three infections, few had four infections, and none had five or more infections.
The risks increase with each infection
Statistical models were used to examine the health risks of reinfection during the first 30 days after infection and up to six months thereafter. The study looked at Covid-19 variants such as Delta, Omicron and BA.5.
Overall, the research team found that people with re-infection with Covid-19 were twice as likely to die and three times more likely to be hospitalized than people without re-infection. In addition, people were three times more likely to develop lung problems than those who had been infected with the virus only once. Negative results occurred in both unvaccinated and vaccinated before reinfection.
Clinical epidemiologist Ziyad Al-Aly, who is one of the authors of the study, is quoted in a statement by the medical school as saying that a sense of invincibility has spread in recent months, “especially among people who have undergone infections and have also been vaccinated.” Some talk about a kind of super immunity to the virus, says Al-Aly. However, the study showed that a second, third or fourth infection leads to additional health risks in the acute phase and in the following months.
The risk seems to increase with each infection. “This means that even after two Covid 19 infections, it is better to avoid the third,” Al-Aly said. “And if you’ve had three infections, you should avoid a fourth. Scientists recommend getting all allowed booster shots and staying home if you are sick. They also recommend getting a flu shot to reduce the chance of a double pandemic of Covid-19 and flu this winter season.