{Reference Type}: Journal Article
{Title}: SARS-CoV-2-specific humoral and cellular immunity persists through 9 months irrespective of COVID-19 severity at hospitalisation.
{Author}: Sandberg JT;Varnaitė R;Christ W;Chen P;Muvva JR;Maleki KT;García M;Dzidic M;Folkesson E;Skagerberg M;Ahlén G;Frelin L;Sällberg M;Eriksson LI;Rooyackers O;Sönnerborg A;Buggert M;Björkström NK;Aleman S;Strålin K;Klingström J;Ljunggren HG;Blom K;Gredmark-Russ S; ;
{Journal}: Clin Transl Immunology
{Volume}: 10
{Issue}: 7
{Year}: 2021
{Factor}: 6.515
{DOI}: 10.1002/cti2.1306
{Abstract}: <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.