Impact of COVID-19 Measures on Invasive Meningococcal Disease

Impact of COVID-19 Measures on Invasive Meningococcal Disease

During the COVID-19 pandemic, the implementation of health and hygiene measures such as wearing masks and social distancing had a positive impact on respiratory infections. Surprisingly, these measures also resulted in a significant decline in invasive meningococcal disease (IMD) cases. However, as the pandemic restrictions started to ease, experts wondered about the potential consequences.

Muhamed-Kheir Taha, a co-lead author of a recent study conducted by the Institut Pasteur, explained that two theories emerged during this period. The first theory suggested that the positive effect observed on respiratory infections might have a long-term impact, causing a decline in the circulation of meningococci. Conversely, the second theory hypothesized that a resurgence of bacterial activity could occur among a population that had not been exposed to the bacteria for an extended period.

To investigate these theories, a team of researchers from the Institut Pasteur analyzed the progression of invasive meningococcal disease in France from 2015 to 2022. They found that the second hypothesis was accurate, with an unprecedented resurgence of the disease occurring after the relaxation of COVID-19 restrictions.

The study revealed a shift in the disease pattern, with an increase in cases caused by meningococcal serogroups that were less common before the pandemic. Moreover, there has been a notable rise in infections among individuals aged 16 to 24. This change suggests that the bacterial strains responsible for invasive meningococcal disease today are different from those that were previously circulating.

The findings of this study have significant implications for vaccination strategies. Currently, in France, only meningitis C vaccination is mandatory, while meningitis B vaccination is recommended for infants. However, there are no specific recommendations for serogroups Y and W in the general population. Consequently, the researchers are collaborating with the French National Authority for Health to adapt future vaccine strategies.

Ala-Eddine Deghmane, one of the study’s co-lead authors, suggests that if the quadrivalent meningococcal vaccine for serogroups A, C, Y, and W were recommended for adolescents, it would not only provide direct protection for them but also offer indirect protection for other population groups. This approach could help mitigate the potential increase in invasive meningococcal disease cases and adapt to the evolving bacterial strains.


What is invasive meningococcal disease?

Invasive meningococcal disease is a severe bacterial infection caused by the bacteria Neisseria meningitidis. It can lead to meningitis, bloodstream infections, and other serious complications.

What are meningococcal serogroups?

Meningococcal serogroups refer to different strains or variations of the Neisseria meningitidis bacteria. The most common serogroups associated with meningococcal disease include A, B, C, Y, and W.

What are the current vaccination recommendations for invasive meningococcal disease in France?

In France, only meningitis C vaccination is mandatory. Vaccination for meningitis B is recommended for infants. However, there are no specific recommendations in the general population for serogroups Y and W.


  • Institut Pasteur. (2023, October). Retrieved from
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