TY - JOUR

T1 - Factors influencing the immune response over 15 months after SARS-CoV-2 infection

T2 - A longitudinal population-wide study in the Faroe Islands

AU - Petersen, Maria Skaalum

AU - Pérez-Alós, Laura

AU - Armenteros, Jose Juan A.

AU - Hansen, Cecilie B.

AU - Fjallsbak, Jógvan Páll

AU - Larsen, Sólrun

AU - Hansen, Jóhanna L.

AU - Jarlhelt, Ida

AU - Kristiansen, Marnar F.

AU - við Streym, Fríða

AU - á Steig, Bjarni

AU - Christiansen, Debes H.

AU - Møller, Lars F.

AU - Strøm, Marin

AU - Andorsdóttir, Guðrið

AU - Gaini, Shahin

AU - Weihe, Pál

AU - Garred, Peter

N1 - Publisher Copyright: © 2022 The Association for the Publication of the Journal of Internal Medicine.

PY - 2023

Y1 - 2023

N2 - Background: The durability of SARS-CoV-2 antibody response and the resulting immunity to COVID-19 is unclear. Objectives: To investigate long-term humoral immunity to SARS-CoV-2. Methods: In this nationwide, longitudinal study, we determined antibody response in 411 patients aged 0–93 years from two waves of infections (March to December 2020) contributing 1063 blood samples. Each individual had blood drawn on 4–5 occasions 1–15 months after disease onset. We measured total anti-SARS-CoV-2 receptor-binding domain (RBD) antibody using a qualitative RBD sandwich ELISA, IgM, IgG and IgA levels using an quantitative in-house ELISA-based assay and neutralizing antibodies (NAbs) using an in-house ELISA-based pseudoneutralizing assay. IgG subclasses were analyzed in a subset of samples by ELISA-based assay. We used nonlinear models to study the durability of SARS-CoV-2 antibody responses and its influence over time. Results: After 15 months, 94% still had detectable circulating antibodies, mainly the IgG isotype, and 92% had detectable NAbs. The distribution of IgG antibodies varied significantly over time, characterized by a biphasic pattern with an initial decline followed by a plateau after approximately 7 months. However, the NAbs remained relatively stable throughout the period. The strength of the antibody response was influenced by smoking and hospitalization, with lower IgG levels in smokers and higher levels in hospitalized individuals. Antibody stability over time was mainly associated with male sex and older age with higher initial levels but more marked decrease. Conclusions: The humoral immune response to SARS-CoV-2 infection varies depending on behavioral factors and disease severity, and antibody stability over 15 months was associated with sex and age.

AB - Background: The durability of SARS-CoV-2 antibody response and the resulting immunity to COVID-19 is unclear. Objectives: To investigate long-term humoral immunity to SARS-CoV-2. Methods: In this nationwide, longitudinal study, we determined antibody response in 411 patients aged 0–93 years from two waves of infections (March to December 2020) contributing 1063 blood samples. Each individual had blood drawn on 4–5 occasions 1–15 months after disease onset. We measured total anti-SARS-CoV-2 receptor-binding domain (RBD) antibody using a qualitative RBD sandwich ELISA, IgM, IgG and IgA levels using an quantitative in-house ELISA-based assay and neutralizing antibodies (NAbs) using an in-house ELISA-based pseudoneutralizing assay. IgG subclasses were analyzed in a subset of samples by ELISA-based assay. We used nonlinear models to study the durability of SARS-CoV-2 antibody responses and its influence over time. Results: After 15 months, 94% still had detectable circulating antibodies, mainly the IgG isotype, and 92% had detectable NAbs. The distribution of IgG antibodies varied significantly over time, characterized by a biphasic pattern with an initial decline followed by a plateau after approximately 7 months. However, the NAbs remained relatively stable throughout the period. The strength of the antibody response was influenced by smoking and hospitalization, with lower IgG levels in smokers and higher levels in hospitalized individuals. Antibody stability over time was mainly associated with male sex and older age with higher initial levels but more marked decrease. Conclusions: The humoral immune response to SARS-CoV-2 infection varies depending on behavioral factors and disease severity, and antibody stability over 15 months was associated with sex and age.

KW - Faroe Islands

KW - infection-acquired immunity

KW - longitudinal study

KW - SARS-CoV-2 antibodies

KW - vaccination-acquired immunity

U2 - 10.1111/joim.13560

DO - 10.1111/joim.13560

M3 - Journal article

C2 - 35996938

AN - SCOPUS:85137206406

VL - 293

SP - 63

EP - 81

JO - Journal of Internal Medicine

JF - Journal of Internal Medicine

SN - 0955-7873

IS - 1

ER -