TY - JOUR

T1 - Longitudinal Evaluation of Severe Acute Respiratory Syndrome Coronavirus 2 T-Cell Immunity Over 2 Years Following Vaccination and Infection

AU - Juhl, Anna Karina

AU - Dietz, Lisa Loksø

AU - Søgaard, Ole Schmeltz

AU - Reekie, Joanne

AU - Nielsen, Henrik

AU - Johansen, Isik Somuncu

AU - Benfield, Thomas

AU - Wiese, Lothar

AU - Stærke, Nina Breinholt

AU - Jensen, Tomas Østergaard

AU - Olesen, Rikke

AU - Iversen, Kasper

AU - Fogh, Kamille

AU - Bodilsen, Jacob

AU - Madsen, Lone Wulff

AU - Lindvig, Susan Olaf

AU - Raben, Dorthe

AU - Andersen, Sidsel Dahl

AU - Hvidt, Astrid Korning

AU - Andreasen, Signe Rode

AU - Baerends, Eva Anna Marianne

AU - Lundgren, Jens

AU - Østergaard, Lars

AU - Tolstrup, Martin

PY - 2024/4/30

Y1 - 2024/4/30

N2 - BackgroundWithin a year of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, vaccines inducing a robust humoral and cellular immune response were implemented worldwide. However, emergence of novel variants and waning vaccine-induced immunity led to implementation of additional vaccine boosters.MethodsThis prospective study evaluated the temporal profile of cellular and serological responses in a cohort of 639 SARS-CoV-2–vaccinated participants, of whom a large proportion experienced a SARS-CoV-2 infection. All participants were infection naïve at the time of their first vaccine dose. Proportions of SARS-CoV-2 spike–specific T cells were determined after each vaccine dose using the activation-induced marker assay, while levels of circulating SARS-CoV-2 antibodies were determined by the Meso Scale serology assay.ResultsWe found a significant increase in SARS-CoV-2 spike–specific CD4+ and CD8+ T-cell responses following the third dose of a SARS-CoV-2 messenger RNA vaccine as well as enhanced CD8+ T-cell responses after the fourth dose. Furthermore, increased age was associated with a poorer response. Finally, we observed that SARS-CoV-2 infection boosts both the cellular and humoral immune response, relative to vaccine-induced immunity alone.ConclusionsOur findings highlight the boosting effect on T-cell immunity of repeated vaccine administration. The combination of multiple vaccine doses and SARS-CoV-2 infections maintains population T-cell immunity, although with reduced levels in the elderly.

AB - BackgroundWithin a year of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, vaccines inducing a robust humoral and cellular immune response were implemented worldwide. However, emergence of novel variants and waning vaccine-induced immunity led to implementation of additional vaccine boosters.MethodsThis prospective study evaluated the temporal profile of cellular and serological responses in a cohort of 639 SARS-CoV-2–vaccinated participants, of whom a large proportion experienced a SARS-CoV-2 infection. All participants were infection naïve at the time of their first vaccine dose. Proportions of SARS-CoV-2 spike–specific T cells were determined after each vaccine dose using the activation-induced marker assay, while levels of circulating SARS-CoV-2 antibodies were determined by the Meso Scale serology assay.ResultsWe found a significant increase in SARS-CoV-2 spike–specific CD4+ and CD8+ T-cell responses following the third dose of a SARS-CoV-2 messenger RNA vaccine as well as enhanced CD8+ T-cell responses after the fourth dose. Furthermore, increased age was associated with a poorer response. Finally, we observed that SARS-CoV-2 infection boosts both the cellular and humoral immune response, relative to vaccine-induced immunity alone.ConclusionsOur findings highlight the boosting effect on T-cell immunity of repeated vaccine administration. The combination of multiple vaccine doses and SARS-CoV-2 infections maintains population T-cell immunity, although with reduced levels in the elderly.

U2 - 10.1093/infdis/jiae215

DO - 10.1093/infdis/jiae215

M3 - Journal article

C2 - 38687181

JO - Journal of Infectious Diseases

JF - Journal of Infectious Diseases

SN - 0022-1899

ER -