TY - JOUR
T1 - The impact and effectiveness of pneumococcal vaccination in Scotland for those aged 65 and over during winter 2003/2004
AU - Mooney, John D.
AU - Weir, Amanda
AU - McMenamin, Jim
AU - Ritchie, Lewis D.
AU - Macfarlane, Tatania V.
AU - Simpson, Colin R.
AU - Ahmed, Syed
AU - Robertson, Chris
AU - Clarke, Stuart C.
PY - 2008/4/23
Y1 - 2008/4/23
N2 - Background
For 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.
Methods
Winter 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.
Results
Overall 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.
Conclusions
The 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.
AB - Background
For 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.
Methods
Winter 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.
Results
Overall 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.
Conclusions
The 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.
KW - scotland
KW - vaccine
KW - 23vPPV
KW - pneumococcal
KW - disease
U2 - 10.1186/1471-2334-8-53
DO - 10.1186/1471-2334-8-53
M3 - Article
SN - 1471-2334
VL - 8
SP - 1
EP - 30
JO - BMC Infectious Diseases
JF - BMC Infectious Diseases
IS - 53
ER -