%0 Journal Article
%T SARS-CoV-2-specific humoral and cellular immunity persists through 9 months irrespective of COVID-19 severity at hospitalisation.
%A Sandberg JT
%A Varnaitė R
%A Christ W
%A Chen P
%A Muvva JR
%A Maleki KT
%A García M
%A Dzidic M
%A Folkesson E
%A Skagerberg M
%A Ahlén G
%A Frelin L
%A Sällberg M
%A Eriksson LI
%A Rooyackers O
%A Sönnerborg A
%A Buggert M
%A Björkström NK
%A Aleman S
%A Strålin K
%A Klingström J
%A Ljunggren HG
%A Blom K
%A Gredmark-Russ S
%A  
%J Clin Transl Immunology
%V 10
%N 7
%D 2021
%M 34257967
%F 6.515
%R 10.1002/cti2.1306
%X <B>OBJECTIVE: </B>Humoral and cellular immunity to SARS-CoV-2 following COVID-19 will likely contribute to protection from reinfection or severe disease. It is therefore important to characterise the initiation and persistence of adaptive immunity to SARS-CoV-2 amidst the ongoing pandemic.<BR><B>METHODS: </B>Here, we conducted a longitudinal study on hospitalised moderate and severe COVID-19 patients from the acute phase of disease into convalescence at 5 and 9 months post-symptom onset. Utilising flow cytometry, serological assays as well as B cell and T cell FluoroSpot assays, we assessed the magnitude and specificity of humoral and cellular immune responses during and after human SARS-CoV-2 infection.<BR><B>RESULTS: </B>During acute COVID-19, we observed an increase in germinal centre activity, a substantial expansion of antibody-secreting cells and the generation of SARS-CoV-2-neutralising antibodies. Despite gradually decreasing antibody levels, we show persistent, neutralising antibody titres as well as robust specific memory B cell responses and polyfunctional T cell responses at 5 and 9 months after symptom onset in both moderate and severe COVID-19 patients.<BR><B>CONCLUSIONS: </B>Our findings describe the initiation and, importantly, persistence of cellular and humoral SARS-CoV-2-specific immunological memory in hospitalised COVID-19 patients long after recovery, likely contributing towards protection against reinfection.