The incidence of invasive pneumococcal serotype 3 disease in the Danish population is not reduced by PCV-13 vaccination

Hans-Christian Slotved; Tine Dalby; Zitta Barrella Harboe; Palle Valentiner-Branth; Victoria Fernandez de Casadevante; Laura Espenhain; Kurt Fuursted; Helle Bossen Konradsen

doi:10.1016/j.heliyon.2016.e00198

The incidence of invasive pneumococcal serotype 3 disease in the Danish population is not reduced by PCV-13 vaccination

Heliyon. 2016 Nov 29;2(11):e00198. doi: 10.1016/j.heliyon.2016.e00198. eCollection 2016 Nov.

Authors

Hans-Christian Slotved¹, Tine Dalby¹, Zitta Barrella Harboe², Palle Valentiner-Branth³, Victoria Fernandez de Casadevante³, Laura Espenhain³, Kurt Fuursted¹, Helle Bossen Konradsen¹

Affiliations

¹ Neisseria and Streptococcus Reference Laboratory, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
² Neisseria and Streptococcus Reference Laboratory, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark; Department of Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
³ Department of Infectious Disease Epidemiology, Statens Serum Institut, Copenhagen, Denmark.

Abstract

Since 2010, Denmark has included the 13-valent pneumococcal conjugated vaccine (PCV-13) in the childhood immunization programme. However, serotype 3 remains as an important cause of invasive pneumococcal disease (IPD) in Denmark. IPD surveillance data (1999-2016) was used to calculate the incidence and age-distribution of serotype 3 IPD, and the effect of PCV-13 on serotype 3 IPD incidence was examined. The incidence of serotype 3 IPD in the age group below 65 years was 0.51/100,000 pre PCV-13, and 0.45/100,000 post PCV-13. In the group 0-4 years, serotype 3 IPD incidence was 0.28/100,000 pre PCV-13, and 0.16/100,000 post PCV-13. Serotype 3 IPD incidence in the elderly showed a mean of 4.27/100,000 pre PCV-13, and 4.32/100,000 post PCV-13. PCV-13 childhood immunization in Denmark has not lead to a reduction of the incidence of IPD caused by serotype 3. The reason behind this missing effect needs to be investigated further.

Keywords: Immunology; Infectious diseases; Medicine.