Response to: Pneumococcal conjugate vaccines in Latin America: are PCV10 and PCV13 similar in terms of protection against serotype 19A?

Exploring the evidence behind the comparable impact of the pneumococcal conjugate vaccines PHiD-CV and PCV13 on overall pneumococcal disease

“… 46 In Sweden, no reduction in the incidence of 19A IPD was seen in 0–2-y-olds in PHiD-CV-using regions (versus the PCV7 period), while, over the same time period, the 19A IPD incidence decreased significantly in PCV13-using regions (no cases identified in the PCV13 period) ( Figure 1 ). 13 Interestingly, while effectiveness estimates for PCV13 against 19A IPD (67–94%) 14 , 23–30 , 35 , 48 tend to be higher than those for PHiD-CV, they were lower than those against 7F and 6A measured in the same studies ( Figure 3 ), 23 , 24 , 28–30 , 35 , 49 suggesting that PCV13 may be less effective against 19A than against other VT. The seemingly lower effectiveness of both vaccines against 19A IPD is consistent with the observation that 19A is still circulating in various settings several years after these vaccines were introduced, 38–41 , 50 , 51 and with the observation that 19A is among the most common VT responsible for PCV13 vaccine failure.…”

Chimeric oligosaccharide conjugate induces opsonic antibodies against Streptococcus pneumoniae serotypes 19A and 19F

“…Invasive pneumococcal diseases (IPD) caused by Streptococcus pneumoniae (Sp), are a major cause of morbidity and mortality in toddlers and older adults worldwide. 2,3 Despite the introduction of a 13-valent pneumococcal conjugate vaccine (PCV13) in 2010, ST19A remains a major pathogen worldwide [4][5][6][7][8] that is associated with 14% of all IPD cases. 9 Since the efficacy of PCV 13 against ST19A is being debated 4,10,11 the development of new vaccine approaches covering ST19A and ST19F is desirable.…”