冰岛DeCODE Genetics-Amgen公司的Kari Stefansson团队对冰岛居民SARS-CoV-2的体液免疫应答进行了研究。2020年9月1日，该研究发表在《新英格兰医学杂志》上。
Title: Humoral Immune Response to SARS-CoV-2 in Iceland
Author: Daniel F. Gudbjartsson, Ph.D.,, Gudmundur L. Norddahl, Ph.D.,, Pall Melsted, Ph.D.,, Kristbjorg Gunnarsdottir, M.Sc.,, Hilma Holm, M.D.,, Elias Eythorsson, M.D., Ph.D.,, Asgeir O. Arnthorsson, M.Sc.,, Dadi Helgason, M.D., Ph.D.,, Kristbjorg Bjarnadottir, Ph.D.,, Ragnar F. Ingvarsson, M.D.,, Brynja Thorsteinsdottir, B.Sc.,, Steinunn Kristjansdottir, B.Sc.,, Kolbrun Birgisdottir, B.Sc.,, Anna M. Kristinsdottir, M.Sc.,, Martin I. Sigurdsson, M.D., Ph.D.,, Gudny A. Arnadottir, M.Sc.,, Erna V. Ivarsdottir, M.Sc.,, Margret Andresdottir, M.Sc.,, Frosti Jonsson, M.Sc.,, Arna B. Agustsdottir, M.Sc.,, Jonas Berglund, Ph.D.,, Berglind Eiriksdottir,, Run Fridriksdottir, M.Sc.,, Elisabet E. Gardarsdottir,, Magnus Gottfredsson, M.D., Ph.D.,, Olafia S. Gretarsdottir, B.Sc.,, Steinunn Gudmundsdottir, M.Sc.,, Kjartan R. Gudmundsson, B.Sc.,, Thora R. Gunnarsdottir, B.Sc.,, Arnaldur Gylfason, M.Sc.,, Agnar Helgason, Ph.D.,, Brynjar O. Jensson, M.Sc.,, Aslaug Jonasdottir, M.Sc.,, Hakon Jonsson, Ph.D.,, Thordur Kristjansson, M.D., Ph.D.,, Karl G. Kristinsson, M.D., Ph.D.,, Droplaug N. Magnusdottir, M.Sc.,, Olafur T. Magnusson, Ph.D.,, Lovisa B. Olafsdottir, M.D.,, Solvi Rognvaldsson, B.Sc.,, Louise le Roux, M.Sc.,, Gudrun Sigmundsdottir, M.D.,, Asgeir Sigurdsson, B.Sc.,, Gardar Sveinbjornsson, M.Sc.,, Kristin E. Sveinsdottir, B.Sc.,, Maney Sveinsdottir, B.Sc.,, Emil A. Thorarensen, B.Sc.,, Bjarni Thorbjornsson, B.Sc.,, Marianna Thordardottir, Ph.D.,, Jona Saemundsdottir, B.Sc.,, S. Hjortur Kristjansson, M.D.,, Kamilla S. Josefsdottir, M.D.,, Gisli Masson, Ph.D.,, Gudmundur Georgsson, B.Sc.,, Mar Kristjansson, M.D.,, Alma Moller, M.D., Ph.D.,, Runolfur Palsson, M.D.,, Thorolfur Gudnason, M.D.,, Unnur Thorsteinsdottir, Ph.D.,, Ingileif Jonsdottir, Ph.D.,, Patrick Sulem, M.D.,, and Kari Stefansson, M.D., Ph.D.
Little is known about the nature and durability of the humoral immune response to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
We measured antibodies in serum samples from 30,576 persons in Iceland, using six assays (including two pan-immunoglobulin [pan-Ig] assays), and we determined that the appropriate measure of seropositivity was a positive result with both pan-Ig assays. We tested 2102 samples collected from 1237 persons up to 4 months after diagnosis by a quantitative polymerase-chain-reaction (qPCR) assay. We measured antibodies in 4222 quarantined persons who had been exposed to SARS-CoV-2 and in 23,452 persons not known to have been exposed.
Of the 1797 persons who had recovered from SARS-CoV-2 infection, 1107 of the 1215 who were tested (91.1%) were seropositive; antiviral antibody titers assayed by two pan-Ig assays increased during 2 months after diagnosis by qPCR and remained on a plateau for the remainder of the study. Of quarantined persons, 2.3% were seropositive; of those with unknown exposure, 0.3% were positive. We estimate that 0.9% of Icelanders were infected with SARS-CoV-2 and that the infection was fatal in 0.3%. We also estimate that 56% of all SARS-CoV-2 infections in Iceland had been diagnosed with qPCR, 14% had occurred in quarantined persons who had not been tested with qPCR (or who had not received a positive result, if tested), and 30% had occurred in persons outside quarantine and not tested with qPCR.
Our results indicate that antiviral antibodies against SARS-CoV-2 did not decline within 4 months after diagnosis. We estimate that the risk of death from infection was 0.3% and that 44% of persons infected with SARS-CoV-2 in Iceland were not diagnosed by qPCR.