Effectiveness of acellular pertussis vaccine and evolution of pertussis incidence in the community of Madrid from 1998 to 2015

Abstract Introduction Pertussis is a communicable disease that primarily affects infants. Vaccination has led to an important reduction in the incidence of the disease, however, resurgence of the disease has been observed. This study aimed to analyze the incidence of pertussis and assess the vaccination effectiveness (VE) of different schedules of acellular pertussis vaccination in the community of Madrid. Methods Pertussis cases notified to the Mandatory Disease Reporting System from 1998 to 2015 were analyzed. Five comparison periods were created: 1998–2001 (reference), 2002–2005, 2006–2009, 2010–2012 and 2013–2015. The incidence ratio (IR) between inter-epidemic periods was analyzed using a Poisson regression. VE was calculated using the screening method. Vaccine status data were collected from the vaccine registry. Results In total, 3855 cases were notified. Inter-epidemic periods were observed every 3–4 years. The incidence increased (IR: 5.99, p  Conclusions B. pertussis is circulating in our population, as shown by the epidemic peaks and increased incidence of pertussis in recent years. VE increased with the number of doses and decreased with the follow-up period. The effect of this and other vaccination strategies must be monitored to control the disease.