The impact and effectiveness of pneumococcal vaccination in Scotland for those aged 65 and over during winter 2003/2004

Abstract

BackgroundFor winter 2003/2004 in Scotland, it was recommended that all those aged 65 and over be eligible to receive 23-valent polysaccharide pneumococcal vaccine (23vPPV), which has been shown to be effective in reducing the risk of invasive pneumococcal disease (IPD). We assessed the success of the vaccination programme by examining the age specific incidence rates of IPD compared to four previous winter seasons and estimating vaccination effectiveness.MethodsWinter season incidence rates of IPD for vaccine targeted (65 years and over) and non-targeted (0–4, 5–34, 35–49, 50–64) age bands were examined for the Scottish population in a retrospective cohort design for winter 2003/2004. Details of all IPD cases were obtained from the central reference laboratory and population vaccine uptake information was estimated from a GP sentinel practice network. Based on the preceding four winter seasons, standardised incidence ratios (SIR) for invasive pneumococcal disease were determined by age-band and sex during winter 2003/2004. Vaccination effectiveness (VE) was estimated using both screening and indirect cohort methods. Numbers needed to vaccinate were derived from VE results using equivalent annual incidence estimates for winter 2003/2004.ResultsOverall vaccination effectiveness using the screening method (adjusted for age and sex) in those aged 65 and over was 61.7% (95%CI: 45.1, 73.2) which corresponded to a number needed to vaccinate of 5206 (95%CI: 4388, 7122) per IPD case prevented. Estimated effectiveness for the same age group using the indirect cohort method was not significant at 51% (95%CI: -278, 94). Reductions in the winter season incidence rate of IPD were highly significant for all those aged 75+: males SIR = 58.8 (95%CI: 41.6, 80.8); females SIR = 70.0 (95%CI: 55.1, 87.8). In the 65–74 years age-group, the reduction for females was significant: SIR = 60.3 (95%CI: 39.3, 88.4), but not for males: SIR = 74.8 (95%CI: 50.8, 106.3). There was no significant protective effect on mortality.ConclusionThe introduction of 23vPPV for those aged 65 and over in Scotland during winter 2003/2004, was accompanied with a reduction of around one third in the incidence of IPD in this age group. Vaccination effectiveness estimates were comparable with those from other developed countries.

Cost-effectiveness analysis of pneumococcal polysaccharide vaccination from age 60 in São Paulo State, Brazil

“…One of these recent studies, conducted in Scotland in persons aged ≥65 years, demonstrated a protective effect of PPV23 against IPD of 61.7% (95% CI, 45.1-73.2). 54 In Spain, a protective effect of 72% (95% CI, 46-95) and 70% (95% CI, 48-82) against IPD was reported by Vila-Corcoles et al 53 in persons over 60 years old, and by Dominguez et al 53 in persons over 65. In the US, IPD vaccine effectiveness of 44% (95% CI, 7-67) in persons …”

“…The mean value of this range was used for the base case: 21% ( Table 2). In addition, as reported in various publications, 11,24,37,38,41,42,53,54,56,62,63 a 10% waning rate each year was applied and a total duration of effectiveness was fixed conservatively at 5 years ( Table 2).…”

“…Indeed, the 37 Maruyama, 2010 (64% against pneumococcal pneumonia and 45% against all cap in nursing home residents); 55 Huss, 2009 (11% in elderly and chronically ill patients against all cap from 11 RcT but high heterogeneity) 54 Vaccine effectiveness …”

“…Meta-analyses of five randomized clinical trials have shown that PPV23 is 68% (95% CI 53-78) effective against IPD among immunocompetent older adults. 49 In our analyses, the values for vaccine effectiveness against were based on multiple observational studies which had the advantage of being conducted in large unselected natural populations 11,37,[50][51][52][53][54][55] (Table 3). One of these recent studies, conducted in Scotland in persons aged ≥65 years, demonstrated a protective effect of PPV23 against IPD of 61.7% (95% CI, 45.1-73.2).…”

Cost-effectiveness of polysaccharide pneumococcal vaccination in people aged 65 and above in Poland

“…Effectiveness against IPD was assumed to be 64% for all elderly (irrespective to underlying conditions) and was calculated as the mean effectiveness observed across multiple observational studies. 47,49,50 Data on NBPPspecific efficacy were scarce and inconclusive. In the base case analysis it was assumed that PPV23 is 21% effective in reducing the number of NBPP infections in the elderly, which represents the average of the efficacy observed from the available evidence (range 0 51,52 to 42%).…”