Effectiveness of the 23-valent pneumococcal polysaccharide vaccine against invasive pneumococcal disease in European older adults by high risk conditions type: results of SpIDnet/I-MOVE+ multicentre study

Camelia Savulescu, R. Carragher, A. SpIDnet/I-MOVE+ group

Research output: Contribution to conferenceAbstractpeer-review


Background: Twenty-three-valent polysaccharide (PPV23) and 13-valent pneumococcal conjugate (PCV13) vaccines are licensed for the prevention of invasive pneumococcal disease (IPD) in the elderly. We measured the PPV23 effectiveness against IPD in adults 65+ year-olds by type of high-risk conditions, pooling surveillance data from seven European sites. PPV23 vaccination is recommended in all sites (8-69% uptake) and PCV13 in those with high-risk conditions in two sites (<5% uptake). Methods: Using IPD cases notified between 2012 and 2016, we compared the vaccination status of IPD cases caused by PPV23 serotypes to that of nonPPV23 IPD (controls) stratified by high-risk condition type: none, immunocompetent and immunocompromising high-risk conditions. We defined PPV23 vaccination as having received at least one dose. We computed PPV23 pooled effectiveness as (1 –odds ratio of vaccination)*100 and confidence intervals (95%CI), adjusted for site, age group, sex, and notification year.Results: We included 1955 cases and 856 controls. In the analyses restricted to IPD with no high-risk conditions (n=849) and immunocompetent high-risk conditions (n=1349), cases were younger than controls (p=0.002, p=0.016, respectively), and less likely to present with meningitis (p=0.037, p=0.001, respectively). There was no difference between cases and controls for the IPD with immunocompromising conditions. PPV23 effectiveness was 55% (95%CI: 29-71), 37% (95%CI: 18-52), 7% (95%CI: -33; 34) for IPD with none, immunocompetent and immunocompromising conditions, respectively (p Mantel-Haenzsel test of homogeneity=0.018). Conclusion: Our findings suggest that the type of high-risk condition modifies the PPV23 effectiveness against PPV23 serotypes IPD. The PPV23 effectiveness was higher among healthy older adults and lower among immunocompromised elderly. These results suggest that vaccine effectiveness by type of high-risk conditions should be taken into account when defining pneumococcal vaccination strategies for older adults.
Original languageEnglish
Publication statusPublished - 22 Nov 2018
EventEuropean Scientific Conference on Applied Infectious Disease Epidemiology 2018 - Hilton Hotel, Saint Julian's, Malta
Duration: 21 Nov 201823 Nov 2018


ConferenceEuropean Scientific Conference on Applied Infectious Disease Epidemiology 2018
Abbreviated titleESCAIDE 2018
CitySaint Julian's
Internet address


  • streptococcus pneumoniae
  • pneumococcal infections
  • pneumococcal vaccine
  • vaccine effectiveness
  • population surveillance

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