In March 2010, Brazil introduced the ten-valent pneumococcal conjugate vaccine ( PCV10 ), which was licensed based on non-inferiority of immunological correlates of protection compared with the seven-valent vaccine.
The schedule comprised three primary doses at ages 2 months, 4 months, and 6 months, and a booster dose at age 12 months.
A single catch-up dose was offered for children aged 12-23 months at the time of introduction.
Researchers have assessed PCV10 effectiveness against invasive pneumococcal disease in Brazilian children.
Invasive pneumococcal disease, defined as isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid, or another normally sterile site, was identified in children age-eligible for at least one PCV10 dose through laboratory-based and hospital-based surveillance in ten states in Brazil from March 1, 2010, until Dec 31, 2012.
The aim of a study was to identify four age-matched and neighbourhood-matched controls for each case. Researchers used conditional logistic regression and calculated PCV10 effectiveness as ( 1-adjusted matched odds ratio ) × 100% for vaccine-type and vaccine-related serotypes ( ie, in the same serogroup as a vaccine serotype ).
In 316 cases ( median age 13.2 months ) and 1219 controls ( 13.3 months ), the adjusted effectiveness of an age-appropriate PCV10 schedule was 83.8% against vaccine serotypes, and 77.9% against vaccine-related serotypes.
Serotype-specific effectiveness was shown for the two most common vaccine serotypes, 14 ( 87.7% ) and 6B ( 82.8% ), and serotype 19A ( 82.2% ), a serotype related to vaccine serotype 19F.
A single catch-up dose in children aged 12-23 months was effective against vaccine-type disease ( 68.0% ).
No significant effectiveness was shown against non-vaccine serotypes for age-appropriate or catch-up schedules.
In the routine immunisation programme in Brazil, PCV10 prevents invasive disease caused by vaccine serotypes. PCV10 might provide cross-protection against some vaccine-related serotypes. ( Xagena )
Domingues CMAS et al, The Lancet Respiratory Medicine 2014; 2: 464-471