Scotland meningococcal strains shifted during pandemic, study finds
Group B became the sole cause of invasive meningococcal disease in Scotland during COVID-19, a Lancet study found.
By Priya Raghavan · Science Reporter
3 min read
A study of Scotland meningococcal strains found that the COVID-19 pandemic period changed which forms of invasive meningococcal disease were circulating, according to the University of Strathclyde. The finding matters for public health because the researchers said strain patterns can change quickly and affect vaccine planning.
The retrospective observational study, published in The Lancet Infectious Diseases, examined invasive meningococcal disease cases in Scotland before, during and after the pandemic, the university said. The paper is titled “Genomic epidemiology of invasive meningococcal disease in Scotland before, during, and after the COVID-19 pandemic.”
What changed in Scotland meningococcal strains?
The researchers found that group B meningococcal disease became the only cause of invasive meningococcal disease in Scotland during the pandemic, according to the University of Strathclyde. Other strains, including groups W and C, declined during that period, the university said.
The study did not find a pandemic-related change in which groups of people were most affected by the disease, according to the university. It did find a change in the strains behind cases.
Four years after the pandemic period assessed in the research, the mix of strains has moved closer to the pre-pandemic pattern, but it has done so from a different baseline, the University of Strathclyde said. The university did not report case totals in its summary of the study.
What is invasive meningococcal disease?
Meningococcal disease is a serious bacterial infection that can lead to meningitis and sepsis, according to the University of Strathclyde. The university said infants and young children, teenagers and young adults, and people over 65 remain among the groups at higher risk.
Because the illness is uncommon but can be severe, the researchers said continued monitoring is important. Dr. Shaun Keegan, a research fellow at the Strathclyde Institute of Pharmacy and Biomedical Sciences and a co-author of the study, said the work shows how genomic surveillance can track which strains are present and how they shift over time, according to the university.
Why does genomic surveillance matter for vaccines?
Genomic surveillance uses genetic information from pathogens to identify and follow strains as they spread or decline. In this study, the University of Strathclyde said that kind of monitoring helped show the pandemic-era dominance of group B and the retreat of other strains.
The researchers said the findings support the use of genomic data in public health protection and vaccine strategy. The university said the study comes as meningococcal disease and vaccination are receiving renewed attention, including the use of MenB vaccines for people at increased risk.
The study was authored by Niall Ahmad and colleagues and published in 2026 in The Lancet Infectious Diseases, according to the University of Strathclyde. The university described the work as peer-reviewed research.
This story draws on original reporting from Medical Xpress.