Effect of 10-valent pneumococcal conjugate vaccine on nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae among children in São Paulo, Brazil.
In March 2010, Brazil introduced the 10-valent pneumococcal conjugate vaccine (PCV10) in the routine infant immunization program using a 4-dose schedule and catch-up for children <23months. We investigated PCV10 effect on nasopharyngeal carriage with vaccine-type Streptococcus pneumoniae (Spn) and non-typeable Haemophilus influenzae (NTHi) among children in São Paulo city. Cross-sectional surveys were conducted in 2010 (baseline) and 2013 (post-PCV10). Healthy PCV-naïve children aged 12-23months were recruited from primary health centers during immunization campaigns. Nasopharyngeal swabs were collected and tested for Hi; for Spn, all baseline and a stratified random sample of 400 post-PCV10 swabs were tested. We compared vaccine-type Spn and NTHi carriage prevalence pre-/post-PCV10, and used logistic regression to estimate PCV10 effectiveness (1-adjusted odds ratio×100%). Overall 501 children were included in the baseline and 1167 in the post-PCV10 survey (including 400 tested for Spn). Spn was detected in 40.3% of children at baseline and 48.8% post-PCV10; PCV10 serotypes were found in 19.8% and 1.8% respectively, representing a decline of 90.9% (p<0.0001). Carriage of vaccine-related serotypes increased (10.8-21.0%, p<0.0001), driven primarily by a rise in serotype 6C (1.8-11.2%, p<0.0001); carriage of serotypes 6A and 19A did not significantly change. PCV10 effectiveness (4 doses) against vaccine-type carriage was 97.3% (95% confidence interval 88.7-99.3). NTHi prevalence increased from 26.0% (130/501) to 43.6% (509/1167, p<0.0001); PCV10 vaccination seemed significantly associated with NTHi carriage, even after adjusting for other known risk factors. Carriage with PCV10 serotypes among toddlers declined dramatically following PCV10 introduction in São Paulo, Brazil. No protection of PCV10 against NTHi was observed. Our findings contribute to a growing body of evidence of PCV10 impact on vaccine-type carriage and highlight the importance of PCV10 as a tool to reduce the burden of pneumococcal disease in Brazil and globally.
National Laboratory for Meningitis and Pneumococcal Infections, Center of Bacteriology, Institute Adolfo Lutz (IAL), São Paulo, Brazil. Electronic address: brandi@ial.sp.gov.br.
Maria-Cristina de C
MC
Brandileone
National Laboratory for Meningitis and Pneumococcal Infections, Center of Bacteriology, Institute Adolfo Lutz (IAL), São Paulo, Brazil. Electronic address: cobo@ial.sp.gov.br.
Rosemeire C
RC
Zanella
National Laboratory for Meningitis and Pneumococcal Infections, Center of Bacteriology, Institute Adolfo Lutz (IAL), São Paulo, Brazil. Electronic address: salmeida@ial.sp.gov.br.
Samanta C G
SCG
Almeida
National Laboratory for Meningitis and Pneumococcal Infections, Center of Bacteriology, Institute Adolfo Lutz (IAL), São Paulo, Brazil; Oswaldo-Cruz Foundation, Rio de Janeiro, Brazil. Electronic address: abrandao@ial.sp.gov.br.
Angela P
AP
Brandao
Institute of Infectious Diseases Emilio Ribas, São Paulo, Brazil. Electronic address: anafribeiro@uol.com.br.
Ana F
AF
Ribeiro
Center of Epidemiologic Surveillance, Secretary of Health of the State of São Paulo, Brazil. Electronic address: telmacarvalhanas@terra.com.br.
Telma-Regina M P
TMP
Carvalhanas
Center of Epidemiologic Surveillance, Secretary of Health of the State of São Paulo, Brazil. Electronic address: hsato@cve.saude.sp.gov.br.
Helena
H
Sato
Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goias, Brazil. Electronic address: alssandrade@gmail.com.
Ana-Lúcia
AL
Andrade
Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA. Electronic address: qzr7@cdc.gov.
Jennifer R
JR
Verani
D001938:Brazil / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D003430:Cross-Sectional Studies; D005260:Female; D006192:Haemophilus Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D006801:Humans; D017589:Immunization Programs; D007223:Infant; D016015:Logistic Models; D008297:Male; D009305:Nasopharynx / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
C586648:10-valent pneumococcal conjugate vaccine; D022242:Pneumococcal Vaccines
Haemophilus influenzae; Pneumococcal carrier; Pneumococcal colonization; Pneumococcal conjugate vaccine; Pneumococcal serotypes; Streptococcus pneumoniae