Why Do We Need a Systematic Review of Pneumococcal Conjugate Vaccine Dosing Schedules?

Supplement I t is well known that Streptococcus pneumoniae remains a leading cause of childhood mortality; in 2008, it was estimated to be responsible for over 500,000 deaths in children aged 1–59 months. 1 It is also known that the pneumococcus is a cause of significant morbidity and mortality among those younger and older than the 1-to 59-month age group, 2,3 although prevention of disease in these age groups has not been the target of global efforts to date. Serious diseases caused by the pneumococcus across all age groups include pneumonia, meningitis and sepsis. Developing countries, mostly in Africa and Asia, carry the highest burden of both pneumococcal disease incidence and mortality in children; this burden is measured both in terms of rates and absolute numbers of cases and deaths. 1 effective vaccines to prevent pneumococcal disease in children exist; access to these life-saving pneumococcal conjugate vaccines (pCV) has become possible in many developing countries through the focused, coordinated efforts of the GAVI Alliance , including all of the key Alliance partners. the World Health Organization, the technical partner that provides global vaccine policy recommendations, advises that pCV be a part of the routine infant vaccine schedule for all countries, but particularly those with highest infant mortality rates and death counts. 4 As of December 2012, 87 countries had introduced pCV into their routine immunization schedule (including a ceremonial launch in 1 country), of which 24 were GAVI-eligible countries. 5,6 An additional 27 GAVI-eligible countries are approved for introduction of pCV in 2013 and beyond. pCVs are being implemented globally, including the poorest countries of the world, at a pace exceeding that of other previously developed vaccines. these vaccines were designed to prevent pneumococcal disease in infants and toddlers, age groups for which previous pneumococcal vaccines were insufficiently protective. the introduction of pCV has been associated with a dramatic decline in pneumococcal disease caused by serotypes included in the vaccine (ie, vaccine-type disease), in children targeted for vaccination and older persons not intended for vaccination (the indirect effect of vaccination). 7–16 the indirect effect on disease results from the impact of pCVs on preventing nasopharyngeal colonization. 17 Reduced colonization leads to reduced spread of the pneumococcus and thus less disease in the unimmunized. 18 to assure that the enormous investments being made in pCV achieve the greatest disease impact, we must move beyond gross metrics of counting the number of …