Levels of SARS-CoV-2 antibodies among fully vaccinated individuals with Delta or Omicron variant breakthrough infections
Research output: Contribution to journal › Journal article › Research › peer-review
Documents
- Fulltext
Final published version, 875 KB, PDF document
The SARS-CoV-2 Omicron variant is associated with high rates of vaccine breakthrough infections, but the immunological basis for this is not well characterised. Here, the authors show that increased anti-Spike IgG antibody levels are associated with a reduced risk of infection with the Delta variant, but not with Omicron.
SARS-CoV-2 variants of concern have continuously evolved and may erode vaccine induced immunity. In this observational cohort study, we determine the risk of breakthrough infection in a fully vaccinated cohort. SARS-CoV-2 anti-spike IgG levels were measured before first SARS-CoV-2 vaccination and at day 21-28, 90 and 180, as well as after booster vaccination. Breakthrough infections were captured through the Danish National Microbiology database. incidence rate ratio (IRR) for breakthrough infection at time-updated anti-spike IgG levels was determined using Poisson regression. Among 6076 participants, 127 and 364 breakthrough infections due to Delta and Omicron variants were observed. IRR was 0.29 (95% CI 0.15-0.56) for breakthrough infection with the Delta variant, comparing the highest and lowest quintiles of anti-spike IgG. For Omicron, no significant differences in IRR were observed. These results suggest that quantitative level of anti-spike IgG have limited impact on the risk of breakthrough infection with Omicron.
Original language | English |
---|---|
Article number | 4466 |
Journal | Nature Communications |
Volume | 13 |
Issue number | 1 |
Number of pages | 8 |
ISSN | 2041-1723 |
DOIs | |
Publication status | Published - 2022 |
ID: 317588187