Reassessing the 1 + 1 pneumococcal conjugate vaccine schedule

In neither of the two case-control studies do the study designs address the potential diminished protection of infants vaccinated at age 3 months and followed to age 12 months. [...]the crux of the argument for a 1 + 1 schedule is that infants will be largely protected by controlling their exposure to vaccine-type pathogens through herd immunity. [...]epidemiological data from the UK indicate that, since 2013, invasive pneumococcal disease incidence among unvaccinated adults (important signalers of herd protection), has stopped decreasing after an initial decline, and has started to rise for some serotypes (eg, serotypes 19F and 19A), suggesting that the indirect herd effect is not complete. 3 NJ Andrews, PA Waight, P Burbidge, Serotype-specific effectiveness and correlates of protection for the 13-valent pneumococcal conjugate vaccine: a postlicensure indirect cohort study, Lancet Infect Dis, Vol. 14, 2014, 839-846 4 CG Whitney, T Pilishvili, MM Farley, Effectiveness of seven-valent pneumococcal conjugate vaccine against invasive pneumococcal disease: a matched case-control study, Lancet, Vol. 368, 2006, 1495-1502