Having passed through a corona infection can protect those who have recovered from being re-infected. But for how long? A U.S. study raises hopes that immune protection after mild courses lasts significantly longer than previously assumed. However, there are already initial doubts about this.
Anyone infected with Corona automatically develops antibodies that protect them against the virus once the disease has been overcome – at least for a certain time. How long this protection actually lasts is still uncertain. Experts fear that the body’s immune response will weaken relatively quickly. However, a new study from the U.S. now raises hope that the body’s own virus defense could be activated in recovered patients for much longer than previously assumed – possibly even for a lifetime.
How long does the protection last?
For their study, published in the journal Nature, the researchers from Washington University School of Medicine examined the blood and bone marrow of 77 patients. The first sample was taken about a month after the first Covid 19 symptoms, and then another three samples were taken at intervals of about three months. They found that antibody levels in subjects with mild courses of covid declined as expected within the first four months after symptom onset. However, this trend slowed in subsequent months. “It’s normal for antibodies to drop after an acute infection, but they don’t drop to zero, they reach a plateau,” explained study co-author Ali Ellebedy.
The reason is long-lived plasma cells in the bone marrow of affected individuals, the research group writes. After surviving a corona infection, small amounts of these antibody-producing cells settle in the bone marrow and can still be detected up to eleven months after the disease. According to the scientists, this indicates that these cells can be activated in the event of a new viral infection. Their conclusion: “People who have had mild disease develop antibody-producing cells that can last a lifetime.”
Experts answer common corona questions
Medical expert Christoph Specht doubts that the immune protection after a survived Corona infection actually lasts that long. This depends on various factors, he says in an interview with ntv. For example, the age of the person affected plays a role: If a young person was ill and has recovered, then it can be assumed that he has a very good immune defense. Accordingly, the protection lasts a relatively long time – but most likely not the whole life, the doctor assumes. That would be very unusual for cold viruses.
“If the same amount of virus now hits an 85-year-old, then it can be assumed that his immune defense is already worse when he is infected. That’s why he’s likely to get more severely ill. And the immune defense will also not last as long,” Specht emphasizes. The U.S. research team also points this out in the study: sufferers with severe symptoms had low antibody levels. “Inflammation plays a big role in severe Covid 19 courses, and too much inflammation can lead to faulty immune responses,” says study author Jackson Turner of Washington University School of Medicine.
Are there differences between the recovered and the vaccinated?
Another criticism Specht makes of the study’s design: Only 77 subjects were studied in it. “It would be good to have a larger number of study participants and then differentiate: What does it actually look like with young people and what does it look like with old people?”
Still, he said, the study is a reason for hope: “Sars-CoV-2 isn’t going away, it’s always going to be there for the next umpteen years. But we’ll be able to get used to it as a society just fine, because we’ll have partial immunity,” the physician says. “It’s all a good outlook and should take some of the panic out of us.”
- source: ntv.de/picture: pixabay.com
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