Invasive Pneumococcal Disease Surveillance, 1 April to 30 June 2017.

The number of notified cases of invasive pneumococcal disease (IPD) in the second quarter of 2017 was greater than the previous quarter and also the second quarter of 2016. Following the July 2011 replacement of the 7-valent pneumococcal conjugate vaccine (7vPCV) in the childhood immunisation program with the 13-valent pneumococcal conjugate vaccine (13vPCV), there was an initial relatively rapid decline in disease due to the additional six serotypes covered by the 13vPCV across all age groups, however more recently this rate of decline has slowed. Additionally, over this period the number of cases due to the eleven serotypes additionally covered by the 23-valent pneumococcal polysaccharide vaccine (23vPPV) and also those serotypes not covered by any available vaccine has been increasing steadily across all age groups.