Long-Term SARS-CoV-2 Specific Immunity Is Affected by the Severity of Initial COVID-19 and Patient Age

Konik, Margarethe; Lindemann, Monika; Zettler, Markus; Meller, Lara; Dolff, Sebastian; Rebmann, Vera; Horn, Peter A.; Dittmer, Ulf; Krawczyk, Adalbert; Schipper, Leonie; Trilling, Mirko; Anastasiou, Olympia Evdoxia; Schwarzkopf, Sina; Thümmler, Laura; Taube, Christian; Schöbel, Christoph; Brenner, Thorsten; Skoda, Eva-Maria; Wilde, Benjamin; Gäckler, Anja; Witzke, Oliver; Rohn, Hana

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the greatest medical challenge. Although crucial to the future management of the pandemic, the factors affecting the persistence of long-term SARS-CoV-2 immunity are not well understood. Therefore, we determined the extent of important correlates of SARS-CoV-2 specific protection in 200 unvaccinated convalescents after COVID-19. To investigate the effective memory response against the virus, SARS-CoV-2 specific T cell and humoral immunity (including virus-neutralizing antibodies) was determined over a period of one to eleven months. SARS-CoV-2 specific immune responses were present in 90% of individual patients. Notably, immunosuppressed patients did not have long-term SARS-CoV-2 specific T cell immunity. In our cohort, the severity of the initial illness influenced SARS-CoV-2 specific T cell immune responses and patients’ humoral immune responses to Spike (S) protein over the long-term, whereas the patients’ age influenced Membrane (M) protein-specific T cell responses. Thus, our study not only demonstrated the long-term persistence of SARS-CoV-2 specific immunity, it also determined COVID-19 severity and patient age as significant factors affecting long-term immunity.