OBJECTIVES: In the UK, PPV23 has been recommended in the elderly (aged 65 and over) and at-risk adults. In 2007, PCV was introduced in children, leading to a decrease in invasive pneumococcal disease (IPD) incidence associated with the PCV serotypes not only in vaccinated children but also in unvaccinated adults. The use of PCV13 in adults is currently under consideration pending data on efficacy in this population. This study aimed to assess the BI of PPV23 vs. NoVac or PCV13 in the UK, accounting for recent epidemiological changes. METHODS: The model was adapted from a previous population-based Markov model, consisting of five health states: no PD, IPD, NBPP (non-bacteraemic pneumococcal pneumonia), post-meningitis sequelae and death. Epidemiology and costs were estimated from UK sources. The analysis tracked cohorts of vaccinated and unvaccinated population between 2012 and 2016. Four scenarios were tested and equal market shares were assumed between PCV13 and PPV23. RESULTS: Over the study period, PPV23 vaccination led to a reduction in the number of IPD cases, ranging from 1,773 to 1,957 (vs. NoVac) or from -154 to 617 (vs. PCV13). The reduction in the number of NBPP cases ranged from -2 to 23,969 (vs. NoVac) or from -11,984 to 0 (vs. PCV13). When compared to NoVac, PPV23 vaccination was associated with a total cost of £63 million, whereas introducing PCV13 required an additional funds of £54 million. The net budget impact ranged between £36 million and £59 million (vs. NoVac) or between -£56 million and -£47 million (vs. PCV13). CONCLUSIONS: The model suggests that vaccinating with PPV23 significantly reduces the burden of pneumococcal disease despite the epidemiological changes. Introducing PCV13 is likely to impose a significant impact on the healthcare budget and assumptions around the efficacy of PCV13 are a substantial source of uncertainty in its public health benefits.