Everyone knows the phenomenon from family or friends. Whenever the cold season begins in winter, the same candidates are always lying down with a cold, fever and cough. If things go bad, they get sick three times in winter for at least a week. Others don’t seem to be challenged by the common cold virus, also a coronavirus, by the way.
For example my 20 year old daughter. It doesn’t knock anything over so quickly. I secretly dream of having a blood transfusion in order to be as protected against all viruses and bacteria as you are.
Has she already gone through Corona without realizing it? Does she have antibodies in her blood and is she immune to a second infection? Millions of people are currently asking themselves the question of immunity to the new SARS-CoV-2 virus. It is not easy to answer because we still know comparatively little.
The US infectiologist and epidemiologist Marc Lipsitch has now explained in the “New York Times” which hypotheses researchers are currently pursuing regarding immunity to corona. Some of the findings come from research into cold viruses. For example, it is known: Anyone who had a strong immune reaction to a febrile infection is better protected against a second infection than someone who only suffered from weak cold symptoms such as a slight runny nose.
To date there has been no vaccination against the cold virus
It is also known that people’s immune systems react differently to pathogens. Cold viruses change so that someone who has had an infection is not automatically immune the next winter. To date there has been no vaccination against the cold virus, nor is there any therapy. We can fly to the moon, but so far we are powerless against coughs, runny nose and hoarseness.
Another source of knowledge for medical professionals are studies on the well-known corona viruses SARS and MERS. Both viral diseases infected comparatively few people. Those affected built antibodies against the virus in their blood and, thanks to their antibodies, were usually immune to re-infection for around two years.
Based on the first findings of corona patients, researchers assume that the protection also lasts for a longer period of time in the case of Covid 19 infections. That’s good news. This would prevent new infections during this period. A major milestone in research will be to find out how long immunity lasts.
We are still far from herd immunity
The more people have gone through a corona infection, the closer a society is to herd immunity. If the corona virus no longer finds enough non-immune victims, it can no longer spread – or its spread is slowed down. Lipsitch and his colleagues are currently assuming that there is still no good immunity even in heavily infested regions.
Only broad-based antibody studies that are now underway will quickly show what percentage of the population is really already behind the infection. In Bavaria and Baden-Württemberg, where there are far more infected people, immunity will therefore be further advanced than in the north, for example.
A Chinese study (not yet tested according to scientific criteria) comes to another important conclusion. Not all infected people could contribute equally to herd immunity. 175 patients with mild Covid-19 symptoms were screened for their antibodies. 70 percent had a strong antibody response, but 25 only a weak one. Five percent did not produce any antibodies at all. In other words: a mild course would not necessarily protect against a new infection. In this respect, researchers now want to increasingly investigate the extent to which the severity of symptoms says something about immunity.
It will be many months before the first vaccination is ready for the market and is supposed to protect everyone, during which each individual should behave extremely carefully. Not out of hysteria, but because nobody knows whether they carry the virus and whether they could infect someone. You also don’t know whether you are already immune or not, any more than your own immune system would cope with an infection.
In view of the risks, nobody wants to find out voluntarily, even if they never get sick and are usually immune to viruses and bacteria, like my daughter.