Cost-effectiveness analysis of pneumococcal polysaccharide vaccination from age 60 in São Paulo State, Brazil

Vaccination of adults aged 60 years and older against Streptococcus pneumonia is not recommended in Brazil. The 23-valent polysaccharide pneumococcal vaccine (PPV23) is only available for institutionalized persons or with underlying diseases despite the substantial medical and economic burden related to pneumococcal infections in adults over than 59 years. The study aimed at evaluating the cost effectiveness of implementing a large PPV program in this population. This analysis was performed using a static decision tree model. Demographic and epidemiological data were obtained from Brazilian official sources and international literature. Economic data were obtained from a study performed in 2007 in a public and a private hospital located in Sao Paulo. Vaccination was assumed to protect for 5 years with 60% effectiveness against bacteremic pneumococcal pneumonia (BPP) and 21% effectiveness against non bacteremic pneumococcal pneumonia (NBPP). Deterministic and sensitivity analyses were performed. The pneumococcal polysaccharide vaccination saved 5,218 life year gained (LYG). The vaccination program was found to be cost effective in the social security and public health care perspectives with a mean incremental cost-effectiveness ratio of R$10,887 and R$8,281 per LYG respectively. Results were sensitive to the vaccine effectiveness against NBPP, the incidence and case-fatality rate of NBPP. From a societal perspective, PPV23 program for adults 60 and older was found to be cost-saving. Pneumococcal polysaccharide vaccination is clinically and economically favored over the present vaccination strategy, in which persons aged over 59 years in Sao Paulo, have not been vaccinated.