Cost-effectiveness of new adult pneumococcal vaccination strategies in Italy

Abstract

Community-acquired pneumonia (CAP) and invasive pneumococcal disease (IPD) are very relevant pathologies among elderly people (≥ 65 y old), with a consequent high disease burden. Immunization with the 23-valent pneumococcal polysaccharide vaccine (PPV23) has been differently implemented in the Italian regions in the past years, reaching overall low coverage rates even in those with medical indications. In 2010, the 13-valent pneumococcal conjugate vaccine (PCV13) became available and recommended in the universal Italian infant immunization program. Since October 2012, indications for use of PCV13 were extended to subjects ≥ 50 y to prevent invasive pneumococcal diseases. The Italian decision makers should now revise regional indications for the prevention of pneumococcal diseases in the elderly. Pharmaco-economic analyses represent a useful tool to value the feasibility of new immunization programs and their sustainability. Therefore, an ad hoc population model was developed in order to value the clinical and economic impact of an adult pneumococcal vaccination program in Italy. Particularly, different immunization scenarios were modeled: vaccination of 65 y-olds (1 cohort strategy), simultaneous vaccination of people aged 65 and 70 y (double cohort strategy) and, lastly, immunization of people aged 65, 70 and 75 y (triple cohort strategy), thus leading to the vaccination of 5, 10 and 15 cohorts during the 5 y of the program. In addition, the administration of a PPV23 dose one year after PCV13 was evaluated, in order to verify the economic impact of the supplemental serotype coverage in elderly people. The mathematical model valued the clinical impact of PCV13 vaccination on the number of bacteraemic pneumococcal pneumonia (BPP) and pneumococcal meningitis (PM) cases, and related hospitalizations and deaths. Although PCV13 is not yet formally indicated for the prevention of pneumococcal CAP by the European Medicine Agency (differently from FDA, whose indications include all pneumococcal diseases in subjects ≥ 50 y), the model calculated also the possible impact of vaccination on CAP cases (non-bacteraemic), considering the rate of this disease due to S. pneumoniae. The results of the analysis show that, in Italy, an age-based PCV13 vaccination program in elderly people is cost-effective from the payer perspective, with costs per QALY ranging from 17,000 to 22,000 Euro, according to the adopted vaccination strategy. The subsequent PPV23 offer results in an increment of costs per QALY (from 21,000 to 28,000 Euro, according to the vaccination strategy adopted). Pneumococcal vaccination using the conjugate vaccine turned out to be already favorable in the second year of implementation, with incremental costs per QALY comparable to those of other already adopted prevention activities in Italy (for instance, universal HPV vaccination of 12 y-old girls), with further benefits obtained when extending the study period beyond the 5-y horizon of our analysis.

A review of economic evaluations of 13-valent pneumococcal conjugate vaccine (PCV13) in adults and the elderly

“…For non-invasive pneumococcal disease, Smith et al (in all 3 studies), 24,26,27 and Rozenbaum et al (Netherlands), 32 included hospitalized NPP whereas, Weycker et al, 25 Cho et al, 28 Pradas et al, 33 and Boccalini et al, 29 included both hospitalised and non-hospitalized NPP in their analyses. Rozenbaum et al (England) 31 did not include NPP in their (base-case) cost-effectiveness analysis.…”

“…39 In terms of the type of economic evaluation, 7 publications were cost-utility analyses, presenting cost per Quality Adjusted Life Year (QALY) gained as the primary outcome. 24,[26][27][28][29]31,32 Whereas the studies by Liguori et al 30 and Pradas et al 33 could be classified as cost-effectiveness analyses, calculating the cost per case of pneumococcal disease avoided as the main outcome. …”

“…For invasive forms of disease, Smith et al, 24,26,27 Rozenbaum et al (England) 31 and Cho et al 28 categorized IPD into meningitis and other IPD. Boccalini et al 29 and Weycker et al 25 used similar approaches but used bactaeremic pneumococcal pneumonia and bacteremia respectively instead of all other IPD. Rozenbaum et al (Netherlands), 32 categorized IPD disease into meningitis, bactaeremic pneumonia, and bactaeremic without focus.…”

“…32 Likewise, in Italy and Spain, although the PPV23 vaccine is recommended for those 65 and high risk 2 y, the coverage rate remains low. 29,30,33 Italy and Spain (partially) have also already introduced PCV13 to their vaccination programs, whereas in the Netherlands, PCV7 was introduced at 2006 and from 2011 PCV10 and PCV13 were available for infants.…”

“…[24][25][26][27][28] two were conducted for Italy 29,30 and the remaining 3 were performed for England, the Netherlands and Spain respectively. [31][32][33] Of the 5 US publications, 3 were authored by Smith et al 24,26,27 with 2 others by Weycker et al and…”