Abstract
BackgroundThe seven-valent pneumococcal conjugate vaccine (PCV-7) was introduced in the Danish childhood immunization program (at 3, 5 and 12 months of age) in 2007 and was replaced with PCV-13 in 2010 without changes to the schedule. After the introduction of these vaccines the incidence of invasive pneumococcal disease (IPD) due to vaccine types (VTs) declined markedly in children aged 0–2 years; however, cases among infants too young to be protected by vaccination have not been studied in detail. We present data on IPD in infants less than 90 days from 1943 until 2013.Study designThe study included all infants younger than 90 days born from 1943 through 2013, who had not been PCV vaccinated and from whom a pneumococcus isolate from blood or cerebrospinal fluid had been submitted to the Danish national reference laboratory. All isolates were serotyped using Pneumotest Latex and Quellung reaction.ResultsA total of 216 IPD cases were identified. The age group specific incidence (total number of IPD cases per 100,000 live births) varied from 0 to 16 in the period 1943 to 2007 and from 1.7 to 9.2 in the period 2008 to 2013. IPD cases due to PCV-7 serotypes were not observed later than 2009.ConclusionIn Danish infants younger than 90 days, IPD due to PCV-7 serotypes has decreased and has not been observed since 2009, but the total incidence of IPD has not changed.
Highlights
Streptococcus pneumoniae is worldwide a cause of high morbidity and mortality among children under 5 years of age and among the elderly [1]
In April 2010, the pneumococcal conjugate vaccine (PCV)-7 was replaced with PCV-13 [7], including six additional serotypes compared to PCV-7
The introduction of PCV has resulted in a decrease in invasive pneumococcal disease (IPD) cases due to vaccine types (VTs) among non-vaccinated individuals, i.e. herd protection, in particular among the elderly [9,10]
Summary
Streptococcus pneumoniae (pneumococcus) is worldwide a cause of high morbidity and mortality among children under 5 years of age and among the elderly [1]. An analysis of data on IPD cases from the last seven decades in Denmark showed that with the introduction of PCV-7 and PCV-13, the incidence of IPD cases due to vaccine serotypes decreased markedly [7,8]. This decline among both vaccinated and non-vaccinated children was observed three years after the introduction of the PCV [5]. After the introduction of these vaccines the incidence of invasive pneumococcal disease (IPD) due to vaccine types (VTs) declined markedly in children aged 0–2 years; cases among infants too young to be protected by vaccination have not been studied in detail. We present data on IPD in infants less than 90 days from 1943 until 2013
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
