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Trial Lecture – time and place
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Adjudication committee
- First opponent: Professor and Docent Asko Järvinen, Helsinki University Hospital,
- Second opponent: Professor Lars Heggelund, University of Bergen,
- Third member and chair of the evaluation committee: Associate professor Cecilie Dahl, University of Oslo
Chair of the Defence
Professor II Kristian Heldal, University of Oslo
Principal Supervisor
Professor II Anne Kristin Møller Fell, University of Oslo
Summary
During the pandemic and in the post-pandemic era, major scientific gaps included the long-term dynamics of antibodies against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) after infection, vaccination, or both, and of possible risk factors for SARS-CoV-2 infection.
The aims of this thesis SARS-CoV-2 antibody persistence and risk factors for SARS-CoV-2 infection A cohort study from Telemark and Agder were to assess the long-term persistence of antibodies and the predictors of changes in SARS-CoV-2 antibody levels following infection and/or vaccination. Furthermore, the aim was to assess potential risk factors for SARS-CoV-2 infection, using a combination of three case–control studies.
Researchers found that humoral immunity in 400 primarily non-hospitalised and non-vaccinated SARS-CoV-2-infected participants lasted for up to 12 months after infection in 96% of the participants, with no symptomatic reinfections reported in the first year. At 12- and 24-month follow-ups, the vast majority of initially polymerase chain reaction (PCR)+ participants retained anti-spike and anti-nucleocapsid antibodies.
Furthermore, Sarjomaa et al. demonstrated the long-term benefits of booster vaccination on humoral immunity in initially SARS-CoV-2-infected and SARS-CoV-2 naïve participants. Long-term antibody levels against the SARS-CoV-2 spike protein were higher in booster-immunized participants vs the non-booster-immunized, irrespective of pre-vaccination infection status. Participants >60 years had the highest median anti-spike antibody levels and were more frequently booster-immunized than younger participants at 24 months. This finding highlights the importance of booster immunization also after SARS-CoV-2 infection.
The study also showed the influence of control group selection in case-control studies investigating risk factors for SARS-CoV-2 infection. Male sex was found to be a potential risk factor for SARS-CoV-2 infection only in the test negative design (TND) study, while smoking was negatively associated with SARS-CoV-2 infection in both the TND and when using population controls.
In conclusion, this study demonstrated long-term persistence of antibodies, underscores the importance of booster-immunization also after SARS-CoV-2 infection and points at the influence of different control groups in case–control studies.
Additional information
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