If a person becomes infected with a new type of coronavirus, it gets immunity to the virus, writes DPA, referring to scientists working on Sars-CoV-2. But it is not yet known exactly how long immunity lasts. Some experts assume that it could be up to two years.
Experts already know that people who develop coronavirus will develop antibodies, said Melanie Brinkmann of the Helmholtz Center for Infection Research in Braunschweig and Friedemann Weber, head of the Institute of Virology at the University of Giessen. Both assume that this immunity could persist in humans for one to two years. Their conjecture is based on experience with other coronaviruses.
The president of the German Immunological Society, Thomas Kamradt, also agrees that people after coronavirus infection will be immune to Sars-CoV-2. “It is likely that you are protected for at least a few years after being infected with Sars-CoV-2,” said Kamradt. How long this immunity lasts, according to him, can not be communicated yet.
Research should be conducted over a longer period of time and the duration of any immunity can be determined accordingly. However, the Covid-19 disease caused by the new type of coronavirus is only briefly known, so long-term studies have not yet been conducted.
How long this protection will last depends on the rate at which the antibody concentration – the so-called titer – will decrease. The higher the titre, the stronger the protection. According to Kamradt, it would be unusual for antibodies against a new type of coronavirus not to develop in the body after a past infection.
Matthias Orth, Director of the Institute for Laboratory Medicine at the Marienhospital Clinic in Stuttgart, points out that it is not yet possible to say with absolute certainty that the antibodies produced will actually protect against further infection. It is not clear what concentration of antibodies provides protection and how often new infections occur.
According to Brinkmann and Weber, the research will be interesting to compare samples of people who have had a different course of the disease. This could explain whether the bodies of patients with a very severe condition even produced antibodies and at what concentration. Research may also explain when specific antibodies begin to develop during infection.
Both scientists consider it important that reliable tests for antibodies be prepared that allow screening. They expect more accurate information about how much of the population has actually been infected, as many people have obviously been infected without knowing it. From these data it will then be possible to determine to what extent the company is immune.
Statistical calculations indicate that to achieve collective immunity, about 60 to 70 percent of the population has to be infected. In such a condition, even without the vaccine, virus spreading stops itself.