An ongoing outbreak of pertussis in Oregon, spanning from 2010 to 2012 and 624 cases, offered the exceptional opportunity to analyse disease severity. Vaccination history, treatment, demographic, and outcome information was available for almost all (98.7%) of the patients, of which 45% were up to date with currently recommended vaccinations. The paper finds:
Ever-vaccinated cases were significantly less likely to be hospitalized or develop severe illness (adjusted odds ratio [aOR], 0.2; 95% confidence interval [CI], .1-.8 and aOR, 0.4; 95% CI, .2-.9, respectively). ACIP up-to-date patients stopped coughing significantly more rapidly than unvaccinated patients (adjusted hazard ratio, 1.7; 95% CI, 1.3-2.2). [my bold]Read more here.