Munich, Germany - 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 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 recognizing and
killing previously recognized 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.