Immunity after COVID-19 - probably most of us wondered how long it could last. Well, the latest research shows that immune memory cells can last up to eight months. Is there any hope for a longer protective effect of SARS-CoV-2 coronavirus vaccines?

Immunity after COVID-19 has been questioned, the authors of the study noted, as anti-SARS-CoV-2 antibodies drop in survivors. It turns out, however, thatthe acquisition of immunity to a previous disease depends on :

  • long-livedmemory T cellsthat recognize specific viral proteins,
  • Memory B cellsresponsible for the production of specific antibodies against the virus.

Immunity after COVID-19: scientists' conclusions

Determining the duration of immunity after the SARS-CoV-2 coronavirus is a kind of challenge for scientists. In the first half of December, the prestigious journal Cell published the results of a study showing thatpeople who have been mildly passed COVID-19 developimmune memory B lymphocytes. Their task is to produce specific antibodies against SARS-CoV-2 when they come into contact with the virus again. The researchers also found thatgood levels of memory B cellspersisted untilaround three months after the onset of disease symptoms.

On the other hand, researchers from several research centers in Australia under the supervision of prof. Menno van Zelma from Monash University from the Department of Immunology and Pathology came to the following conclusion. Memory B lymphocytes, which specifically recognize SARS-CoV-2, , remain in the body of survivors for at least eight months .

Immunity after COVID-19: do survivors actually retain it?

The study was conducted in a small group of 25 patients from whomwas blood drawn between day 4 and day 242 after symptoms had subsided . Other studies also showed that the level of antibodies to SARS-CoV-2began to decline from the 20th day after infection , and more specifically after the symptoms disappeared. These were antibodies against the receptor binding domain (RBD) of the proteinS peak virus and against nucleocapsid protein (NCP).

Additionally, memory B lymphocytes that specifically recognize thereceptor binding domain or the SARS-CoV-2nucleocapsid protein were detected in the blood of patients (after infection). Memory B cells increased by day 150 post infection and lasted for at least 242 days (eight months) after symptom resolution.

In the opinion of prof. van Zelm, the obtained results are significant. "They definitely indicate thatpatients infected with the virus that causes COVID-19 do indeed retain resistance to the virus and disease ," he explained. The results also explain why there are so few cases of actual reinfection with SARS-CoV-2 among the millions of people infected worldwide. Prof. van Zelm was even tempted to say that this latest work on immunity after COVID-19gives hope that coronavirus vaccines will protect us for a long time .

Source: PAP

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Category:

Infectious diseases