{"entity": "publication", "iuid": "ff02f9c6b49d44158d7914971d5dbb30", "timestamp": "2026-08-20T20:42:23.514Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/ff02f9c6b49d44158d7914971d5dbb30.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/ff02f9c6b49d44158d7914971d5dbb30"}}, "title": "SARS-CoV-2-specific B- and T-cell immunity in a population-based study of young Swedish adults.", "authors": [{"family": "Bj\u00f6rkander", "given": "Sophia", "initials": "S"}, {"family": "Du", "given": "Likun", "initials": "L"}, {"family": "Zuo", "given": "Fanglei", "initials": "F"}, {"family": "Ekstr\u00f6m", "given": "Sandra", "initials": "S"}, {"family": "Wang", "given": "Yating", "initials": "Y"}, {"family": "Wan", "given": "Hui", "initials": "H"}, {"family": "Sherina", "given": "Natalia", "initials": "N"}, {"family": "Schoutens", "given": "Lisanne", "initials": "L"}, {"family": "Andr\u00e9ll", "given": "Juni", "initials": "J"}, {"family": "Andersson", "given": "Niklas", "initials": "N"}, {"family": "Georgelis", "given": "Antonios", "initials": "A"}, {"family": "Bergstr\u00f6m", "given": "Anna", "initials": "A"}, {"family": "Marcotte", "given": "Harold", "initials": "H"}, {"family": "Kull", "given": "Inger", "initials": "I"}, {"family": "Hammarstr\u00f6m", "given": "Lennart", "initials": "L"}, {"family": "Mel\u00e9n", "given": "Erik", "initials": "E"}, {"family": "Pan-Hammarstr\u00f6m", "given": "Qiang", "initials": "Q"}, {"family": "BAMSE COVID-19 study group", "given": "", "initials": ""}], "type": "clinical trial", "published": "2022-01-00", "journal": {"title": "J. Allergy Clin. Immunol.", "issn": "1097-6825", "volume": "149", "issue": "1", "pages": "65-75.e8", "issn-l": "0091-6749"}, "abstract": "Young adults are now considered major spreaders of coronavirus disease 2019 (COVID-19) disease. Although most young individuals experience mild to moderate disease, there are concerns of long-term adverse health effects. The impact of COVID-19 disease and to which extent population-level immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exists in young adults remain unclear.\n\nWe conducted a population-based study on humoral and cellular immunity to SARS-CoV-2 and explored COVID-19 disease characteristics in young adults.\n\nWe invited participants from the Swedish BAMSE (Barn [Children], Allergy Milieu, Stockholm, Epidemiology) birth cohort (age 24-27 years) to take part in a COVID-19 follow-up. From 980 participants (October 2020 to June 2021), we here present data on SARS-CoV-2 receptor-binding domain-specific IgM, IgA, and IgG titers measured by ELISA and on symptoms and epidemiologic factors associated with seropositivity. Further, SARS-CoV-2-specific memory B- and T-cell responses were detected for a subpopulation (n = 108) by ELISpot and FluoroSpot.\n\nA total of 28.4% of subjects were seropositive, of whom 18.4% were IgM single positive. One in 7 seropositive subjects was asymptomatic. Seropositivity was associated with use of public transport, but not with sex, asthma, rhinitis, IgE sensitization, smoking, or body mass index. In a subset of representative samples, 20.7% and 35.0% had detectable SARS-CoV-2 specific B- and T-cell responses, respectively. B- and T-cell memory responses were clearly associated with seropositivity, but T-cell responses were also detected in 17.2% of seronegative subjects.\n\nAssessment of IgM and T-cell responses may improve population-based estimations of SARS-CoV-2 infection. The pronounced surge of both symptomatic and asymptomatic infections among young adults indicates that the large-scale vaccination campaign should be continued.", "doi": "10.1016/j.jaci.2021.10.014", "pmid": "34695490", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC8536496"}, {"db": "pii", "key": "S0091-6749(21)01626-2"}], "notes": [], "created": "2026-08-20T07:58:20.068Z", "modified": "2026-08-20T07:58:20.083Z"}