This retrospective observational study examined the genomic and demographic characteristics of invasive meningococcal disease (IMD) in Scotland across three periods: pre-COVID-19 (July 2009–March 2020), COVID-19 (March 2020–March 2022), and post-COVID-19 (March 2022–April 2026), using interrupted time-series analyses on 1,143 reported cases.
Of 27 pre-specified variables analysed, 6 changed between pre-COVID-19 and COVID-19 periods: genogroup B and MenB-FHbp-preventable status increased, while genogroups W and C, clonal complex 11, and polysaccharide-preventable status all decreased. By 2025–26, genogroup and lineage distributions had returned toward pre-COVID-19 patterns from a new baseline. No demographic changes (age, sex, deprivation) were associated with the pandemic.
Only culture-confirmed cases (512/1,143; 44.8%) had genomic data, potentially missing genomic shifts in culture-negative cases. The study is observational, limiting causal inference. Scotland-only data may limit generalisability to other settings.
High-risk groups—infants under 1, children aged 1–4, adolescents/young adults aged 15–24, and adults 65+—remained consistently affected regardless of pandemic-era shifts, reinforcing the need for sustained, targeted vaccination. Integrated real-time genomic surveillance is essential to track capsular group fluctuations and guide timely vaccine policy updates.
Explore related topics
