German scientists from the Jena University Hospital (UKJ, Germany) have proven that not everyone who becomes ill from the coronavirus also produces antibodies against that virus. It remains to be seen if they also do not build up any immunity. Last week it became apparent that people can get Corona at least twice. In Hong Kong, a man who contracted COVID-19 in April turned out to be infected with this disease a second time.
The UKJ started a study in Neustadt in Thuringia back in May this year. The town, which has a population of just under 1,000 residents, was under quarantine for a fortnight as of 22 March 2020. At the end of this period, 49 people were found to be infected. Two of whom died.
A team of 10 scientists examined all residents for the virus. Via swabs for acute infections and antibody tests for previous infections. They took blood and throat wash samples, asked for details of any symptoms, as well as possible exposure to the virus.
No antibodies detected despite SARS-Cov-2 infection
The scientists working with Prof. Mathias Pletz, director of the UKJ Institute of Infectious Medicine and Hospital Hygiene, came to an even more surprising conclusion after their research. Not all of those individuals who were diagnosed as infected at the beginning of the year had antibodies in their blood.
“We were surprised that half of the infected people who had been diagnosed with the virus 6 weeks earlier, did not have antibody titers (titer = quantity of certain antibodies in the blood; ed.), even though we looked for them in six different tests,” Prof. Pletz notes. “This surprising result raises a lot of new questions. It is evident that even with a negative antibody test, it can’t really be ruled out that a COVID infection has happened before.”
Further research
Moreover, it is not clear “whether the lack of antibody production following a COVID infection can be equated with a lack of immunity,” said the infectiologist. In order to get to the bottom of this question, scientists from the Institute of Immunology, under the direction of Prof. Dr. Thomas Kamradt, are now carrying out further research.
They are looking for specific immune cells in study subjects who have not produced antibodies despite having a confirmed infection. However, these studies are extremely thorough and are still ongoing. In addition, the researchers are planning further research in Neustadt next autumn.
