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Vikström, Linnea
Publikasjoner (5 av 5) Visa alla publikasjoner
Wigren, J., Vikström, L., Rosendal, E., Gröning, R., Gwon, Y.-D., Nilsson, E., . . . Forsell, M. N. E. (2023). At-home sampling to meet geographical challenges for serological assessment of SARS-CoV-2 exposure in a rural region of northern Sweden, March to May 2021: a retrospective cohort study. Eurosurveillance, 28(13), Article ID 2200432.
Åpne denne publikasjonen i ny fane eller vindu >>At-home sampling to meet geographical challenges for serological assessment of SARS-CoV-2 exposure in a rural region of northern Sweden, March to May 2021: a retrospective cohort study
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2023 (engelsk)Inngår i: Eurosurveillance, ISSN 1025-496X, E-ISSN 1560-7917, Vol. 28, nr 13, artikkel-id 2200432Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background: The current SARS-CoV-2 pandemic has highlighted a need for easy and safe blood sampling in combination with accurate serological methodology. Venipuncture for testing is usually performed by trained staff at healthcare centres. Long travel distances to healthcare centres in rural regions may introduce a bias of testing towards relatively large communities with closer access. Rural regions are therefore often not represented in population-based data.

Aim: The aim of this retrospective cohort study was to develop and implement a strategy for at-home testing in a rural region of Sweden during spring 2021, and to evaluate its role to provide equal health care for its inhabitants.

Methods: We developed a sensitive method to measure antibodies to the S-protein of SARS-CoV-2 and optimised this assay for clinical use together with a strategy of at-home capillary blood sampling.

Results: We demonstrated that our ELISA gave comparable results after analysis of capillary blood or serum from SARS-CoV-2-experienced individuals. We demonstrated stability of the assay under conditions that reflected temperature and humidity during winter or summer. By assessment of capillary blood samples from 4,122 individuals, we could show both feasibility of the strategy and that implementation shifted the geographical spread of testing in favour of rural areas.

Conclusion: Implementation of at-home sampling enabled citizens living in remote rural areas access to centralised and sensitive laboratory antibody tests. The strategy for testing used here could therefore enable disease control authorities to get rapid access to information concerning immunity to infectious diseases, even across vast geographical distance.

sted, utgiver, år, opplag, sider
European Centre for Disease Control and Prevention (ECDC), 2023
Emneord
coronavirus disease (COVID-19), laboratory, surveillance, Sweden
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-206673 (URN)10.2807/1560-7917.ES.2023.28.13.2200432 (DOI)000971868200003 ()36995373 (PubMedID)2-s2.0-85151573640 (Scopus ID)
Tilgjengelig fra: 2023-04-14 Laget: 2023-04-14 Sist oppdatert: 2023-09-05bibliografisk kontrollert
Blom, K., Fjällström, P., Molnár, C., Åberg, M., Vikström, L., Wigren, J., . . . Johansson, A. (2023). SARS-CoV-2-related mortality decrease in nursing home residents given multiple COVID-19 boosters [Letter to the editor]. The Lancet - Infectious diseases, 23(10), e393-e394
Åpne denne publikasjonen i ny fane eller vindu >>SARS-CoV-2-related mortality decrease in nursing home residents given multiple COVID-19 boosters
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2023 (engelsk)Inngår i: The Lancet - Infectious diseases, ISSN 1473-3099, E-ISSN 1474-4457, Vol. 23, nr 10, s. e393-e394Artikkel i tidsskrift, Letter (Annet vitenskapelig) Published
sted, utgiver, år, opplag, sider
Elsevier, 2023
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-215072 (URN)10.1016/S1473-3099(23)00548-0 (DOI)37716359 (PubMedID)2-s2.0-85172367341 (Scopus ID)
Tilgjengelig fra: 2023-10-13 Laget: 2023-10-13 Sist oppdatert: 2024-01-17bibliografisk kontrollert
Vikström, L., Fjällström, P., Gwon, Y.-D., Sheward, D. J., Wigren-Byström, J., Evander, M., . . . Forsell, M. N. E. (2023). Vaccine-induced correlate of protection against fatal COVID-19 in older and frail adults during waves of neutralization-resistant variants of concern: an observational study. The Lancet Regional Health: Europe, 30, Article ID 100646.
Åpne denne publikasjonen i ny fane eller vindu >>Vaccine-induced correlate of protection against fatal COVID-19 in older and frail adults during waves of neutralization-resistant variants of concern: an observational study
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2023 (engelsk)Inngår i: The Lancet Regional Health: Europe, E-ISSN 2666-7762, Vol. 30, artikkel-id 100646Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background: To inform future preventive measures including repeated vaccinations, we have searched for a clinically useful immune correlate of protection against fatal COVID-19 among nursing homes residents.

Methods: We performed repeated capillary blood sampling with analysis of S-binding IgG in an open cohort of nursing home residents in Sweden. We analyzed immunological and registry data from 16 September 2021 to 31 August 2022 with follow-up of deaths to 30 September 2022. The study period included implementation of the 3rd and 4th mRNA monovalent vaccine doses and Omicron virus waves.

Findings: A total of 3012 nursing home residents with median age 86 were enrolled. The 3rd mRNA dose elicited a 99-fold relative increase of S-binding IgG in blood and corresponding increase of neutralizing antibodies. The 4th mRNA vaccine dose boosted levels 3.8-fold. Half-life of S-binding IgG was 72 days. A total 528 residents acquired their first SARS-CoV-2 infection after the 3rd or the 4th vaccine dose and the associated 30-day mortality was 9.1%. We found no indication that levels of vaccine-induced antibodies protected against infection with Omicron VOCs. In contrast, the risk of death was inversely correlated to levels of S-directed IgG below the 20th percentile. The death risk plateaued at population average above the lower 35th percentile of S-binding IgG.

Interpretation: In the absence of neutralizing antibodies that protect from infection, quantification of S-binding IgG post vaccination may be useful to identify the most vulnerable for fatal COVID-19 among the oldest and frailest. This information is of importance for future strategies to protect vulnerable populations against neutralization resistant variants of concern.

sted, utgiver, år, opplag, sider
Elsevier, 2023
Emneord
Correlate of protection, COVID-19, Immune monitoring of vulnerable populations, Longevity of vaccination, Open cohort study, Vaccination, Vulnerable population
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-208263 (URN)10.1016/j.lanepe.2023.100646 (DOI)2-s2.0-85156247971 (Scopus ID)
Forskningsfinansiär
Swedish Research CouncilScience for Life Laboratory, SciLifeLabKnut and Alice Wallenberg FoundationVinnovaSwedish Association of Local Authorities and RegionsFamiljen Erling-Perssons Stiftelse
Tilgjengelig fra: 2023-05-24 Laget: 2023-05-24 Sist oppdatert: 2023-07-14bibliografisk kontrollert
Castro Dopico, X., Muschiol, S., Grinberg, N. F., Aleman, S., Sheward, D. J., Hanke, L., . . . Karlsson Hedestam, G. B. (2022). Probabilistic classification of anti-SARS-CoV-2 antibody responses improves seroprevalence estimates. Clinical & Translational Immunology (CTI), 11(3), Article ID e1379.
Åpne denne publikasjonen i ny fane eller vindu >>Probabilistic classification of anti-SARS-CoV-2 antibody responses improves seroprevalence estimates
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2022 (engelsk)Inngår i: Clinical & Translational Immunology (CTI), E-ISSN 2050-0068, Vol. 11, nr 3, artikkel-id e1379Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Objectives: Population-level measures of seropositivity are critical for understanding the epidemiology of an emerging pathogen, yet most antibody tests apply a strict cutoff for seropositivity that is not learnt in a data-driven manner, leading to uncertainty when classifying low-titer responses. To improve upon this, we evaluated cutoff-independent methods for their ability to assign likelihood of SARS-CoV-2 seropositivity to individual samples. Methods: Using robust ELISAs based on SARS-CoV-2 spike (S) and the receptor-binding domain (RBD), we profiled antibody responses in a group of SARS-CoV-2 PCR+ individuals (n = 138). Using these data, we trained probabilistic learners to assign likelihood of seropositivity to test samples of unknown serostatus (n = 5100), identifying a support vector machines-linear discriminant analysis learner (SVM-LDA) suited for this purpose. Results: In the training data from confirmed ancestral SARS-CoV-2 infections, 99% of participants had detectable anti-S and -RBD IgG in the circulation, with titers differing > 1000-fold between persons. In data of otherwise healthy individuals, 7.2% (n = 367) of samples were of uncertain serostatus, with values in the range of 3-6SD from the mean of pre-pandemic negative controls (n = 595). In contrast, SVM-LDA classified 6.4% (n = 328) of test samples as having a high likelihood (> 99% chance) of past infection, 4.5% (n = 230) to have a 50–99% likelihood, and 4.0% (n = 203) to have a 10–49% likelihood. As different probabilistic approaches were more consistent with each other than conventional SD-based methods, such tools allow for more statistically-sound seropositivity estimates in large cohorts. Conclusion: Probabilistic antibody testing frameworks can improve seropositivity estimates in populations with large titer variability.

sted, utgiver, år, opplag, sider
John Wiley & Sons, 2022
Emneord
antibody responses, antibody testing, COVID-19, probability, SARS-CoV-2, serology
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-193709 (URN)10.1002/cti2.1379 (DOI)000773551400002 ()35284072 (PubMedID)2-s2.0-85127258616 (Scopus ID)
Forskningsfinansiär
NIH (National Institutes of Health), 400 SUM1A44462‐02Wellcome trust, 107881Wellcome trust, 220788Swedish Research Council, 2017‐00968
Tilgjengelig fra: 2022-04-25 Laget: 2022-04-25 Sist oppdatert: 2022-12-09bibliografisk kontrollert
Normark, J., Vikström, L., Yong-Dae, G., Persson, I.-L., Edin, A., Björsell, T., . . . Forsell, M. N. E. (2021). Heterologous ChAdOx1 nCoV-19 and mRNA-1273 Vaccination [Letter to the editor]. New England Journal of Medicine, 385(11), 1049-1051
Åpne denne publikasjonen i ny fane eller vindu >>Heterologous ChAdOx1 nCoV-19 and mRNA-1273 Vaccination
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2021 (engelsk)Inngår i: New England Journal of Medicine, ISSN 0028-4793, E-ISSN 1533-4406, Vol. 385, nr 11, s. 1049-1051Artikkel i tidsskrift, Letter (Fagfellevurdert) Published
sted, utgiver, år, opplag, sider
Massachusetts Medical Society, 2021
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-187330 (URN)10.1056/NEJMc2110716 (DOI)000674415300001 ()34260850 (PubMedID)2-s2.0-85111281855 (Scopus ID)
Tilgjengelig fra: 2021-09-08 Laget: 2021-09-08 Sist oppdatert: 2022-04-27bibliografisk kontrollert
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