How Long Does COVID-19 Immunity Last?

The COVID-19 pandemic is caused by the coronavirus SARS-CoV-2. Because the disease is relatively new, it is not known so far how long immunity lasts after a COVID-19 infection. The body produces antibodies to fight the infection, but their levels drop significantly after a few weeks or months. However, it also produces so-called memory B cells that persist after an infection, recognize the pathogen, and quickly generate antibodies again upon a second exposure.

Saurabh Mehandru, Icahn School of Medicine at Mount Sinai, New York, USA, Paul D. Bieniasz, Michel C. Nussenzweig, The Rockefeller University, New York, and Howard Hughes Medical Institute, Baltimore, MD, both USA, Marina Caskey, The Rockefeller University, and colleagues have studied the immune response of 87 individuals that had been infected with COVID-19. The antibody response in their plasma and the number and activity of memory B cells was assessed at 1.3 and 6.2 months after infection.

The team observed that memory B cell responses do not decay after 6.2 months, but instead continue to evolve. This suggests that individuals who are infected with SARS-CoV-2 can have an effective immune response to the virus upon repeat exposure for at least half a year. The researchers also found that SARS-CoV-2 nucleic acids persisted in the small bowel of some patients four months after the infection. Such residual viral particles could be driving the evolution of memory cells.

Evolution of antibody immunity to SARS-CoV-2,
Christian Gaebler, Zijun Wang, Julio C. C. Lorenzi, Frauke Muecksch, Shlomo Finkin, Minami Tokuyama, Alice Cho, Mila Jankovic, Dennis Schaefer-Babajew, Thiago Y. Oliveira, Melissa Cipolla, Charlotte Viant, Christopher O. Barnes, Yaron Bram, Gaëlle Breton, Thomas Hägglöf, Pilar Mendoza, Arlene Hurley, Martina Turroja, Kristie Gordon, Katrina G. Millard, Victor Ramos, Fabian Schmidt, Yiska Weisblum, Divya Jha, Michael Tankelevich, Gustavo Martinez-Delgado, Jim Yee, Roshni Patel, Juan Dizon, Cecille Unson-O’Brien, Irina Shimeliovich, Davide F. Robbiani, Zhen Zhao, Anna Gazumyan, Robert E. Schwartz, Theodora Hatziioannou, Pamela J. Bjorkman, Saurabh Mehandru, Paul D. Bieniasz, Marina Caskey, Michel C. Nussenzweig,
Nature 2021.
https://doi.org/10.1038/s41586-021-03207-w

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