Australian researchers have revealed – for the first time – that people who have been infected with the COVID-19 virus have immune memory to protect against reinfection for at least eight months.
Research is the strongest evidence of the likelihood that vaccines against the virus, SARS-CoV-2, will work for long periods of time. Earlier, many studies showed that the first wave of antibodies against coronavirus decreased after the first few months, raising concerns that people may lose immunity quickly. This new paper calms these concerns.
The study is the result of a collaboration in several centers, led by Associate Professor Menno van Zelm, of the Department of Immunology and Pathology at Monash University, with the Alfred Research Alliance between Monash University, Alfred Hospital and the Burnet Institute, and published today in the prestigious journal , Scientific immunology. The publication reveals that specific cells in the immune system called memory B cells “remember” the infection with the virus and, if challenged again, by re-exposure to the virus, triggers a protective immune response by rapidly producing protective antibodies.
The researchers recruited a cohort of 25 patients with COVID-19 and took 36 blood samples from them from day 4 postinfection to day 242 postinfection.
As with other studies – analyzing only the response to antibodies – the researchers found that antibodies to the virus began to decline 20 days after infection.
However – importantly – all patients continued to have memory B cells that recognized one of the two components of the SARS-CoV-2 virus, the tip and nucleocapsid proteins. These virus-specific memory B cells were stably present for up to eight months after infection.
According to Associate Professor van Zelm, the results give hope for the effectiveness of any vaccine against the virus and also explain why there have been so few examples of genuine reinfection in the millions of people who have tested positive for the virus globally.
“These results are important because they show, in the end, that patients infected with COVID-19 virus actually retain immunity against the virus and the disease,” he said.
“This has been a black cloud that hangs over the potential protection that could be provided by any COVID-19 vaccine and offers real hope that once a vaccine or vaccines are developed, they will provide long-term protection.”
Follow the latest news about the coronavirus outbreak (COVID-19)
Rapid generation of sustainable B cell memory to SARS-CoV-2 and nucleocapsid proteins in COVID-19 and convalescence, Scientific immunology 22 Dec 2020: Vol. 5, Number 54, eabf8891, DOI: 10.1126 / sciimmunol.abf8891, immunology.sciencemag.org/content/5/54/eabf8891
Provided by Monash University
Citation: COVID immunity lasts at least eight months, new data reveals (2020, December 22) retrieved December 23, 2020 from https://medicalxpress.com/news/2020-12-covid-immunity-months-reveals.html
This document is subject to copyright. Apart from any fair transaction for the purpose of private study or research, no part may be reproduced without written permission. The content is provided for informational purposes only.