The number of antibodies against the coronavirus decreases faster than expected in recovered patients. This could dampen hope for long-term vaccination.
Setback in corona research: Experts had hoped that recovered Covid-19 patients could be protected against a new infection longer by the formation of antibodies. And these antibodies should also be used to develop a vaccine that can provide long-term protection against corona infection. However, new blood tests from German corona patients are dampening this hope: The concentration of the antibodies decreases faster than expected after the illness has been overcome. This could also diminish the hope of being able to quickly develop a long-term vaccine against the virus.
Sobering result
The data refer to nine patients who were treated at the Munich Clinic Schwabing at the end of January and show those affected significant decrease in the so-called neutralizing antibodies. This was confirmed by the chief physician of the clinic for infectiology based there, Clemens Wendtner. "In four of the nine patients, we see declining neutralizing antibodies in a very special test that can only be carried out in a high-security laboratory," said the doctor.
New infection possible
One must continue to observe whether this could have negative consequences for possible long-term immunity. But the data suggest that you can get Covid-19 back in the near future after you've already had an infection. However, not only the examined antibodies are crucial for a possible immunity, the so-called T cell immunity also plays a role. The T lymphocytes specifically target virus-infected cells. And this defense works better if the attacking virus is already known to the T cells. The T lymphocytes could therefore step in as protection, even if the neutralizing antibodies decrease.
Although the new results are not particularly meaningful for only nine test subjects, the small study fits in with existing data. For example, Chinese researchers had previously found out how quickly the number of antibodies decreased in recovered patients: According to this, it only took two months for those affected without symptoms to reduce the antibodies.
But even those who suffered from strong symptoms were not long protected by a high number of antibodies. And: Patients with few symptoms also generally developed fewer antibodies, her immune system was less prepared for the virus. The researchers published the results in the journal Nature Medicine.