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 ...

We analyzed pertussis reporting, death, hospitalization, and serodiagnostic data from 1976 to 1998 to help explain the cause of the 1996 pertussis outbreak in the Netherlands. The unexpected outbreak was detected by an increase in pertussis reporting and by other surveillance methods. In 1996, according to reporting and serologic data, the increase in pertussis incidence among (mostly unvaccina...

UNLABELLED To determine factors associated with obstetric provider recommendation of pertussis vaccine (Tdap) to their pregnant patients following the Advisory Committee on Immunization Practices (ACIP) recommendation that Tdap be given in the third trimester of each pregnancy. Obstetric providers across New York State anonymously completed a standard set of questions to assess vaccine recommen...

BACKGROUND In 2012 England and Wales experienced a resurgence of pertussis and an increase in infant deaths. This occurred 8 years after acellular pertussis (aP) vaccine replaced whole cell (wP) primary vaccine despite continued high coverage for the primary series and pre-school aP booster. We developed a mathematical model to describe pertussis transmission dynamics in England and Wales since...

Hemophilus pertussis vaccine injected into normal rat skin produced local edema lasting several days. Four to 6 days later the injected site became severely inflamed. When uninjected skin was challenged 5 to 28 days after the initial injection, severe inflammation developed at the site of challenge within 12 to 24 hours. This secondary hypersensitive response was elicited by a dose of vaccine w...

OBJECTIVES The purpose of this work was to evaluate the long-term effectiveness of vaccination with acellular pertussis vaccines at 3, 5, and 12 months of age. METHODS Clinical follow-up of reported culture- and polymerase chain reaction-confirmed cases of pertussis was initiated during October 1997 in most of Sweden (except Gothenburg and environs). The study population included 90% of Swedi...

The recent increase in Bordetella pertussis incidence (whooping cough) presents a challenge to global health. Recent studies have called into question the effectiveness of acellular B. pertussis vaccination in reducing transmission. Here we examine the epidemiological consequences of an ineffective B. pertussis vaccine. Using a dynamic transmission model, we find that: 1) an ineffective vaccine...

There is evidence that pertussis is reemerging in vaccinated populations. We have proposed, and provided evidence for, one explanation for this phenomenon in The Netherlands: antigenic divergence between vaccine strains and circulating strains. Finland has a pertussis vaccination history very similar to that of The Netherlands, and yet there is no evidence for an increase in the incidence of pe...

Although pertussis is a vaccine-preventable infection, vaccine-induced immunity is not lifelong and booster doses are recommended according to national disease epidemiology. The aim of this study was to evaluate pertussis-IgG levels in school-aged students in Ahvaz, south-west Islamic Republic of Iran. In a descriptive, cross-sectional study, blood samples were obtained from 640 students (382 b...

BACKGROUND Between July 1997 and April 1998, universal childhood immunization programs in Canada changed from using a whole-cell pertussis to a 5-component acellular pertussis-containing vaccine. To assess effects on pertussis epidemiology of this nationwide change, we analyzed hospitalizations during 1991-2004 using the Canadian Immunization Monitoring Program, Active (IMPACT) pertussis databa...