Table 2.
Observed and Predicted Changes in Incidence of Vaccine-Type and Nonvaccine-Type Invasive Pneumococcal Disease Following Administration of 7-Valent Pneumococcal Conjugate Vaccine in 6 Study Populations (Model 1)a
| Observed % Change |
95% CI | Predicted % Changeb |
95% PI | Predicted % Changec |
95% PI | |
|---|---|---|---|---|---|---|
| Vaccine serotypes | ||||||
| Alaska (rural) | −98.8 | −99.8, −91.2 | −87.6 | −95.7, −67.4 | −87.8 | −95.5, −67.6 |
| Alaska (urban) | −98.4 | −99.6, −93.6 | −86.2 | −90.9, −77.6 | −86.2 | −91.0, −78.7 |
| England and Wales | −94.8 | −96.2, −92.9 | −77.3 | −90.7, −45.1 | −77.1 | −90.4, −48.3 |
| Massachusettsd | −97.1 | −99.6, −77.9 | −91.8 | −96.6, −80.9 | −92.9 | −97.2, −81.3 |
| Navajo/WMA | −99.2 | −99.9, −94.6 | −90.3 | −95.0, −82.6 | −90.5 | −95.0, −82.4 |
| The Netherlands | −96.9 | −99.6, −77.8 | −90.6 | −94.6, −84.1 | −90.8 | −94.4, −84.0 |
| Nonvaccine serotypes | ||||||
| Alaska (rural) | 115.4 | 51.5, 206.3 | 74.0 | 23.1, 141.9 | 78.0 | 3.4, 204.1 |
| Alaska (urban) | 110.6 | 41.8, 212.8 | 65.2 | 27.7, 112.3 | 57.7 | 19.5, 107.8 |
| England and Wales | 85.5 | 59.6, 115.6 | 204.4 | 106.1, 343.1 | 171.0 | 85.3, 300.9 |
| Massachusettsd | 22.3 | −11.8, 69.7 | 41.6 | 10.0, 79.8 | 32.4 | 2.9, 73.8 |
| Navajo/WMA | 8.2 | −16.3, 39.8 | 20.2 | −0.8, 47.1 | 2.3 | −19.5, 30.0 |
| The Netherlands | 48.1 | −16.9, 164.1 | 37.0 | 4.1, 86.0 | 42.1 | 2.4, 99.6 |
Abbreviations: CI, confidence interval; PCV7, 7-valent pneumococcal conjugate vaccine; PI, predictive interval; WMA, White Mountain Apache.
a The table shows estimates from the most recent postvaccine period for which data were available from each study site. The carriage samples shown were from Alaska (2004 and 2008), England (2008/2009), Massachusetts (2009), the Navajo/WMA (2006–2008), and the Netherlands (2010), and the invasive pneumococcal disease data were from the corresponding periods indicated in Web Table 1. Years post-PCV7 during which the data were collected for each state/country: Alaska, 4–8 years after vaccination; Navajo/WMA, 6–8 years; the Netherlands, 3–4 years; England and Wales, 3 years; Massachusetts, 8 years (see Web Table 1).
b Data in the model were stratified by vaccine serotype (vaccine type/nonvaccine type).
c Data in the model were stratified by vaccine serotype (vaccine type/high-incidence nonvaccine type/low-incidence nonvaccine type).
d The reference sample for Massachusetts was collected 1 year after vaccine introduction, not before PCV7 introduction.