Covid, how long immunity lasts: new discovery about “memory”

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Although the arrival of day V is imminent, that is the day of one of the vaccines in Italy, many wonder How long does immunity to coronavirus last? for those undergoing treatment and for those who have already been infected in the past and have contracted Covid-19. Immune memory, according to an Australian study, protects against reinfection of at least eight months.

Published in Science Immunology, the new research offers important results because it reinforces the likelihood that vaccines arriving soon in Europe, and therefore Italy, will work for long periods.

Coronavirus, how the immune system response works

Some specific cells of the immune system, called memory B cells, are capable of “Remember” the infection by the virus and through re-exposure to the virus itself, they can trigger a protective immune response through the rapid production of antibodies.

Immunity to coronavirus, the researchers’ experiment

To arrive at their discovery, the researchers recruited 25 patients with Covid-19 and they took 36 blood samples from day 4 after infection to day 242. Later, as in other studies, the researchers found that antibodies to the virus began to decline 20 days after infection.

However, the novelty that emerged is that all patients continued to have memory B cells which “recognized” one of the two protein components of the SARS-CoV-2 virus.

Cells of “memory”, the discovery

Memory B cells The researchers found that the specific viruses were stably present for up to eight months after infection. According to the teacher Menno van Zelm, from Monash University, one of the authors of the research, the results give hope in the efficacy of any vaccine against the virus and also explain why there have been so few examples of actual reinfection among millions of people who tested positive for the virus around the world.

VIRGILIO NEWS | 12-23-2020 16:24