Poland was one of the last European countries to introduce PCV10 into the childhood immunization program. Available data on the epidemiology of pneumococcal meningitis was scarce and fragmented due to two surveillance systems. Aleksandra Polkowska-Kramek conducted a comprehensive analysis of the incidence, mortality, serotype distribution, and antimicrobial susceptibility of pneumococcal meningitis, characterizing the baseline epidemiology before conjugate vaccine introduction. She also highlighted some limitations of the passive reporting system that should be accounted for in future vaccine effectiveness studies.
The impact of pneumococcal conjugate vaccines on the burden of invasive pneumococcal diseases (IPD) is well investigated in many countries, but only a limited number of studies report specifically on pneumococcal meningitis. In her dissertation, Polkowska-Kramek focused on the contribution of S. pneumoniae to the burden of bacterial meningitis in Finland. She showed that despite the available PCV10 vaccine, pneumococcus remained a leading cause of bacterial meningitis and mortality. Even though the overall incidence of PCV10 serotype meningitis decreased in vaccine-eligible children and unvaccinated adults seven years after PCV10 introduction, substantial disease burden remains in older adults because of increases in pneumococcal meningitis caused by non-PCV10 serotypes.
In conclusion, the dissertation addressed gaps in knowledge on the baseline epidemiology of pneumococcal meningitis in Poland and provided detailed data on the population effects of PCV10 vaccination on pneumococcal meningitis in Finland. The epidemiology of pneumococcal disease is constantly evolving due to the existence of over 100 S. pneumoniae serotypes. The incomplete herd protection and serotype replacement we observed will continue to challenge the next generation of researchers until new types of effective and serotype independent vaccines are developed.
Public defence on Friday 10 May
The doctoral dissertation of MPH Aleksandra Polkowska-Kramek in the field of epidemiology titled Epidemiology of Pneumococcal Meningitis Before and After the Introduction of 10-valent Pneumococcal Conjugate Vaccine (PCV10) in Poland and Finland will be publicly examined at the Faculty of Social Sciences, Tampere University, at 12:00 on Friday 10 May 2024. The venue is auditorium F114 of the Arvo building, address: Arvo Ylpön katu 34, Tampere. The Opponent will be Professor Carlos G Grijalva from Vanderbilt University, USA. The Custos will be Professor Pekka Nuorti from Tampere University.
The doctoral dissertation is available online.
The public defence can be followed via a remote connection
Photo: Tomasz Kramek