Berlin
How long does the immune protection last in vaccinated people after a corona disease? Researchers have now found an answer to this question.
The combination of vaccination and disease protects against further infection longer than a booster vaccination. This is proven by several studies recently published in the journal “The Lancet”. Accordingly protect the so-called “hybrid immunity“, the result of vaccination and illness, at least eight months before reinfection with the coronavirus.
The combination protects 95 percent from a severe course or hospitalization within the next six to twelve months. This emerges from another meta-study on the subject. The immunity after a booster vaccination, it disappears a little faster.
Corona: Omicron variant failed to bypass protection
However, experts warn that immunity always depends on how the virus develops. When a virus variant arises, which bypasses the reaction of the immune system, the combination of vaccination and disease does not protect against further infection.
In a study on duration of immunity Researchers looked at numbers on corona diseases from vaccinated people in Portugal. At the end of 2021 and at the beginning of 2022, the Omicron variants BA.1 and BA.2 were mainly used there. Then BA.5 gradually spread. The study came to the conclusion that vaccinated people who became infected with BA.1 or BA.2 subsequently showed high immunity – also against BA.5. Vaccinated people without a primary infection had a sixteen times higher risk of contracting BA.5 than vaccinated BA.1/BA.2 patients. Their immunity was still very high after eight months – the duration of the study.
Immune system: Better protected after illness than after a booster
A study from Sweden among medical staff came to similar conclusions. Here, too, an immunity of at least eight months was shown in vaccinated persons after an initial illness. The subjects also had a high concentration of antibodies in the nasal mucosa. These suggest better protection against infection than antibodies in the blood.
Taken together, the studies suggest that “hybrid immunity” does in fact protect against recurrence for at least eight months. The resulting immunity lasts longer than after one booster vaccination. An Israeli study of medical workers who had been vaccinated at least three times found that after a fourth vaccination, protection wears off after just four months. Although some subjects were still infected after three vaccinations, no one became seriously ill.
Covid protection: Boosters for those who are already ill still make sense
So are booster vaccinations superfluous? Not necessarily. First of all, the statistics say nothing about the risk of infection of each individual. Because that risk of infection depends on other factors such as age, gender and genetics. In addition, the virus continues to develop and it cannot be ruled out that mutations will form that also bypass the “hybrid” immune protection.
In particular for people with previous illnesses, it can therefore continue to make sense to use immune protection booster vaccinations to maintain. For young people who have already been exposed to the virus, this may not be necessary at the moment. (lro)
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