A recent study conducted by the Institut Pasteur has unveiled a concerning increase in invasive meningococcal disease (IMD) in France in the aftermath of the COVID-19 pandemic. This resurgence highlights the necessity of adjusting vaccination strategies to tackle evolving public health challenges.
Researchers from the Institut Pasteur examined data from the National Reference Center for Meningococci to analyze the progression of IMD in France from 2015 to 2022. Published in the Journal of Infection and Public Health, the study reveals a significant rise in the number of cases following the relaxation of COVID-19 restrictions. Notably, there has been a shift in affected age groups and bacterial strains during this resurgence.
The impact of COVID-19 measures on IMD during the pandemic demonstrated a significant decrease in infections, attributed to health and hygiene practices such as mask-wearing and social distancing. However, the study also raises questions about the post-pandemic scenario. Would the positive effect on IMD continue, or would there be a rapid resurgence of bacterial activity in a population that had minimal contact with the bacteria for an extended period?
The study’s findings confirm the second hypothesis. A comprehensive analysis of IMD cases between 2015 and 2022 indicated an unprecedented resurgence of the disease. Even before the winter peak, the number of recorded cases between January and September 2023 has already exceeded the figures from the pre-COVID-19 period. The rise can be attributed to various factors, including weaker general immunity due to reduced strain circulation and a decrease in vaccination rates.
Furthermore, the emergence of different meningococcal serogroups, particularly serogroups W and Y, has been observed. These strains differ from those prevalent before the pandemic and predominantly affect individuals aged 16 to 24. The situation indicates a system reset caused by the COVID-19 epidemic.
Considering the potential increase in cases and the influence of seasonal influenza, there is an urgent need to reassess vaccine strategies. While meningitis C vaccination is mandatory in France, vaccination for other serogroups is recommended only for infants. The Institut Pasteur scientists are collaborating with the French National Authority for Health to adapt the future vaccine strategy and potentially recommend quadrivalent meningococcal vaccines for broader age groups. This approach could provide direct protection for adolescents and indirect protection for the wider population.
Q: What is invasive meningococcal disease (IMD)?
A: Invasive meningococcal disease is a severe bacterial infection caused by the Neisseria meningitidis bacterium. It can lead to meningitis, bloodstream infections, and potentially life-threatening complications.
Q: What are meningococcal serogroups?
A: Meningococcal bacteria can be classified into different serogroups based on the specific structures present on their surfaces. The most common serogroups associated with invasive disease are A, B, C, W, X, and Y.
Q: How does COVID-19 impact invasive meningococcal disease?
A: The COVID-19 pandemic and the associated health measures, such as mask-wearing and social distancing, initially led to a decrease in invasive meningococcal disease cases. However, the relaxation of these measures has resulted in a significant resurgence of the disease.
Q: What changes should be made to vaccine strategies?
A: The study recommends considering the inclusion of quadrivalent meningococcal vaccines that cover serogroups A, C, Y, and W in vaccination strategies. Expanding vaccination recommendations to adolescents could provide direct protection and indirect protection to other population groups.