Impact of 2+1 pneumococcal conjugate vaccine program in the province of Quebec, Canada.
BACKGROUND
Quebec was the first jurisdiction in the world to recommend a 3-dose (2+1) pneumococcal conjugate vaccine (PCV) schedule. The program was implemented in December 2004 with a catch-up for children <5 years. PCV-7 was first used and replaced, respectively, by PCV-10 in 2009 and by PCV-13 in 2011.


METHODS
Cases of invasive pneumococcal disease (IPD) notified to public health authorities and isolates submitted to the provincial reference laboratory during the period 2000-2011 were analyzed.


RESULTS
IPD incidence in children <5 years was 67/100,000 in 2001-2004, and decreased to 32/100,000 in 2007-2009 following PCV-7 implementation (p<0.01). A further decrease to 24/100,000 was observed in 2010-2011 following PCV-10 introduction (p<0.01). PCV-7 serotypes represented 82% of the total IPD cases in 2000-2004 and elimination was achieved in 2011. Main emerging serotypes were 19A and 7F. Children exposed to the PCV-10 experienced lower IPD rates and all serotypes contributed to the decline, mainly 7F and 19A. In adults, a decrease of low magnitude was observed in 2005-2006 but rates in 2007-2009 were higher than in the prevaccination period.


CONCLUSIONS
A 3-dose PCV schedule with high uptake is highly effective and should be recommended worldwide. Serotype replacement eroded benefits especially in adults. PCV-10 introduction had an effect and the impact of PCV-13 use remains to be evaluated.
Department of Social and Preventive Medicine, Laval University, Quebec City, Canada; Quebec National Public Health Institute (Institut national de Santé publique du Québec), Quebec City, Canada; Quebec University Hospital Research Centre, Quebec City, Canada. Electronic address: philippe.dewals@criucpq.ulaval.ca.
Philippe
P
De Wals
Quebec Public Health Laboratory (Laboratoire de santé publique du Québec), Quebec National Public Health Institute (Institut national de Santé publique du Québec), Montreal, Canada.
Brigitte
B
Lefebvre
Quebec Ministry of Health and Social Services (Ministère de la Santé et des Services sociaux du Québec), Montreal, Canada.
France
F
Markowski
Quebec University Hospital Research Centre, Quebec City, Canada.
Geneviève
G
Deceuninck
Quebec University Hospital Research Centre, Quebec City, Canada.
Fannie
F
Defay
Quebec National Public Health Institute (Institut national de Santé publique du Québec), Quebec City, Canada.
Monique
M
Douville-Fradet
Quebec Ministry of Health and Social Services (Ministère de la Santé et des Services sociaux du Québec), Montreal, Canada.
Monique
M
Landry
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002675:Child, Preschool; D018563:Disease Notification; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D017589:Immunization Programs; D007115:Immunization Schedule; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D011792:Quebec / Q000453:epidemiology; D012042:Registries; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification; D018074:Vaccines, Conjugate / Q000627:therapeutic use; D055815:Young Adult
C586648:10-valent pneumococcal conjugate vaccine; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
Effectiveness; Herd immunity; Immunization program; Pneumococcal conjugate vaccine; Replacement