Reduction of invasive pneumococcal disease 3 years after the introduction of the 13-valent conjugate vaccine in the Oxfordshire region of England.
BACKGROUND
The 7-valent pneumococcal conjugate (PCV7) vaccine's impact on invasive pneumococcal disease (IPD) is well described, but few reports exist on the additional impact of the 13-valent vaccine (PCV13).


METHODS
We calculated the IPD incidence across all ages in a surveillance project following implementation of PCV7 (in September 2006) and PCV13 (in April 2010) in children aged <2 years (11 hospitals; 4935 cases).


RESULTS
The overall incidence decreased from 10 cases/100 000 persons per year in 1996-1997 to 8 cases/100 000 persons per year in 2007-2008 and 7 cases/100 000 in 2012-2013. Declines were greater in children aged <2 years (from 37 cases/100 000 in 1996-1997 to 29 and 14 cases/100 000 in 2007-2008 and 2012-2013, respectively). The incidence of IPD due to PCV7 serotypes decreased in all ages after PCV7 introduction (P < .001), whereas the incidence of IPD due to the additional 6 serotypes in PCV13 and to nonvaccine types (NVTs) increased in children aged ≥2 years (P < .001 for both comparisons). The incidence of IPD due to the 6 additional serotypes in PCV13 declined significantly after PCV13 introduction in all ages (P ≤ .01), and the incidence of IPD due to NVTs declined significantly in children aged ≥2 years (P = .003). In 2011-2013, the overall incidences of IPD due to PCV7 serotypes, the 6 additional serotypes in PCV13, and NVTs were 0.3, 2.8, and 4.4 cases/100 000; the incidences among children aged <2 years were 0.9, 2.4, and 10.8 cases/100 000, respectively.


CONCLUSIONS
The annual incidence of IPD due to vaccine serotypes (1-3 cases/100 000) among children aged <2 years and nontarget groups demonstrates the success of PCV7 and PCV13. A substantially higher incidence of IPD due to NVTs indicates the importance of ongoing surveillance and extension of vaccine polyvalency.
Nuffield Department of Medicine, University of Oxford.
Catrin E
CE
Moore
Nuffield Department of Medicine, University of Oxford Public Health England, Royal Sussex County Hospital, Brighton.
John
J
Paul
Nuffield Department of Medicine, University of Oxford.
Dona
D
Foster
Nuffield Department of Medicine, University of Oxford.
Saeed A
SA
Mahar
Nuffield Department of Medicine, University of Oxford.
David
D
Griffiths
Nuffield Department of Medicine, University of Oxford Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom.
Kyle
K
Knox
Nuffield Department of Medicine, University of Oxford.
Timothy E
TE
Peto
Nuffield Department of Medicine, University of Oxford.
A Sarah
AS
Walker
Nuffield Department of Medicine, University of Oxford.
Derrick W
DW
Crook
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D055815:Young Adult
C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines
13-valent pneumococcal conjugate vaccine; 7-valent pneumococcal conjugate vaccine; Streptococcus pneumonia; epidemiology; invasive pneumococcal disease; pneumococcal conjugate vaccines