RT Journal Article
SR Electronic
T1 Effectiveness of pertussis vaccination and duration of immunity
JF Canadian Medical Association Journal
JO CMAJ
FD Canadian Medical Association
SP E399
OP E406
DO 10.1503/cmaj.160193
VO 188
IS 16
A1 Schwartz, Kevin L.
A1 Kwong, Jeffrey C.
A1 Deeks, Shelley L.
A1 Campitelli, Michael A.
A1 Jamieson, Frances B.
A1 Marchand-Austin, Alex
A1 Stukel, Therese A.
A1 Rosella, Laura
A1 Daneman, Nick
A1 Bolotin, Shelly
A1 Drews, Steven J.
A1 Rilkoff, Heather
A1 Crowcroft, Natasha S.
YR 2016
UL http://www.cmaj.ca/content/188/16/E399.abstract
AB Background: A resurgence of pertussis cases among both vaccinated and unvaccinated people raises questions about vaccine effectiveness over time. Our objective was to study the effectiveness of the pertussis vaccine and characterize the effect of waning immunity and whole-cell vaccine priming.Methods: We used the test-negative design, a nested case–control study with test-negative individuals as controls. We constructed multivariable logistic regression models to estimate odds ratios (ORs). Vaccine effectiveness was calculated as (1 – OR) × 100. We assessed waning immunity by calculating the odds of developing pertussis per year since last vaccination and evaluated the relative effectiveness of priming with acellular versus whole-cell vaccine.Results: Between Dec. 7, 2009, and Mar. 31, 2013, data on 5867 individuals (486 test-positive cases and 5381 test-negative controls) were available for analysis. Adjusted vaccine effectiveness was 80% (95% confidence interval [CI] 71% to 86%) at 15–364 days, 84% (95% CI 77% to 89%) at 1–3 years, 62% (95% CI 42% to 75%) at 4–7 years and 41% (95% CI 0% to 66%) at 8 or more years since last vaccination. We observed waning immunity with the acellular vaccine, with an adjusted OR for pertussis infection of 1.27 (95% CI 1.20 to 1.34) per year since last vaccination. Acellular, versus whole-cell, vaccine priming was associated with an increased odds of pertussis (adjusted OR 2.15, 95% CI 1.30 to 3.57).Interpretation: We observed high early effectiveness of the pertussis vaccine that rapidly declined as time since last vaccination surpassed 4 years, particularly with acellular vaccine priming. Considering whole-cell vaccine priming and/or boosters in pregnancy to optimize pertussis control may be prudent.