A study by scientists in the southern German city of Munich suggests coronavirus antibodies may not remain in the body longer than a few months, dampening hopes of an effective vaccine or long-term immunity.
Tests on patients treated at Munich’s Schwabing Clinic showed a significant drop in the number of so-called neutralising antibodies in the blood, said Clemens Wendtner, senior consultant at the hospital’s department for infectious diseases.
“In four of the nine patients, we see falling neutralising antibodies in a very special test that can only be carried out in a high-security laboratory,” said Clemens Wendtner.
“The extent to which this has an impact on long-term immunity and vaccination strategies is still speculative, but must be monitored critically as it progresses,” he added.
The results suggest that recovered patients can be re-infected with the virus, though further tests are necessary to confirm this, Wendtner said.
The body’s immune response is made up of both B-cells, responsible for secreting antibodies, and T-cells, capable of recognising and killing previously recognised antigens.
Both are relevant for long-term immunity.
Wendtner’s findings chime with other studies around the world.
Chinese researchers reported in the journal Nature that the presence of coronavirus antibodies in the blood decreased sharply after two months. This was especially true in asymptomatic patients, who produced fewer antibodies and therefore a weaker immune response.