Characterization of the SARS-CoV-2 antibody landscape in Norway in the late summer of 2022: high seroprevalence in all age groups with patterns of primary Omicron infection in children and hybrid immunity in adults.

Autor: Tunheim G; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway. gro.tunheim@fhi.no., Fossum E; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Robertson AH; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Rø GØI; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Chopra A; Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway., Vaage JT; Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway., Vikse EL; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Kran AB; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Magnus P; Center for Fertility and Health, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Trogstad L; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Mjaaland S; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Hungnes O; Division of Infection Control, Norwegian Institute of Public Health (NIPH), Oslo, Norway., Lund-Johansen F; Department of Immunology, Oslo University Hospital and University of Oslo, Oslo, Norway.
Jazyk: angličtina
Zdroj: BMC infectious diseases [BMC Infect Dis] 2024 Aug 20; Vol. 24 (1), pp. 841. Date of Electronic Publication: 2024 Aug 20.
DOI: 10.1186/s12879-024-09670-w
Abstrakt: Background: According to Norwegian registries, 91% of individuals ≥ 16 years had received ≥ 1 dose of COVID-19 vaccine by mid-July 2022, whereas less than 2% of children < 12 years were vaccinated. Confirmed COVID-19 was reported for 27% of the population, but relaxation of testing lead to substantial underreporting. We have characterized the humoral immunity to SARS-CoV-2 in Norway in the late summer of 2022 by estimating the seroprevalence and identifying antibody profiles based on reactivity to Wuhan or Omicron-like viruses in a nationwide cross-sectional collection of residual sera, and validated our findings using cohort sera.
Methods: 1,914 anonymized convenience sera and 243 NorFlu-cohort sera previously collected from the Oslo-area with reported infection and vaccination status were analyzed for antibodies against spike, the receptor-binding domain (RBD) of the ancestral Wuhan strain and Omicron BA.2 RBD, and nucleocapsid (N). Samples were also tested for antibodies inhibiting RBD-ACE2 interaction. Neutralization assays were performed on subsets of residual sera against B.1, BA.2, XBB.1.5 and BQ.1.1.
Results: The national seroprevalence estimate from vaccination and/or infection was 99.1% (95% CrI 97.0-100.0%) based on Wuhan (spike_W and RBD_W) and RBD_BA2 antibodies. Sera from children < 12 years had 2.2 times higher levels of antibodies against RBD_BA2 than RBD_W and their seroprevalence estimate showed a 14.4 percentage points increase when also including anti-RBD_BA2 antibodies compared to Wuhan-antibodies alone. 50.3% (95% CI 45.0-55.5%) of residual sera from children and 38.1% (95% CI 36.0-40.4%) of all residual sera were positive for anti-N-antibodies. By combining measurements of binding- and ACE2-RBD-interaction-inhibiting antibodies, reactivity profiles indicative of infection and vaccination history were identified and validated using cohort sera. Residual sera with a profile indicative of hybrid immunity were able to neutralize newer Omicron variants XBB.1.5 and BQ.1.1.
Conclusions: By late summer of 2022, most of the Norwegian population had antibodies to SARS-CoV-2, and almost all children had been infected. Antibody profiles indicated that children mostly had experienced a primary Omicron infection, while hybrid immunity was common among adults. The finding that sera displaying hybrid immunity could neutralize newer Omicron variants indicates that Wuhan-like priming of the immune response did not have a harmful imprinting effect and that infections induce cross-reacting antibodies against future variants.
(© 2024. The Author(s).)
Databáze: MEDLINE
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