A model-based analysis: what potential could there be for a S. aureus vaccine in a hospital setting on top of other preventative measures?

BACKGROUND: Over the past decade, there has been sustained interest and efforts to develop a S. aureus vaccine. There is a need to better evaluate the potential public health impact of S. aureus vaccination, particularly given that preventative measures exist to reduce infection. To our knowledge, there is no previous work to assess the potential of a S. aureus vaccine to yield additional MRSA infection reduction in a hospital setting, on top of other preventative measures that already proved efficient. METHODS: The main objectives were to propose a versatile simulation framework for assessing potential added benefits of a hypothetical S. Aureus vaccine in conjunction with other preventative measures, and to illustrate possibilities in a given hospital setting. To this end, we employed a recently published dynamic transmission modelling framework that we further adapted and expanded to include a hypothetical S. aureus vaccination component in order to estimate potential benefits of vaccinating patients prior to hospital admission. RESULTS: Model-based projections indicate that even with other hygiene prevention measures in place, vaccination of patients prior to hospital admission has the potential to provide additional reduction of MRSA infection. Vaccine coverage and vaccine efficacy are key factors that would ultimately impact the magnitude of this reduction. For example, in an average case scenario with 50% decolonization, 50% screening and 50% hygiene compliance level in place, S. aureus vaccination with 25% vaccine coverage, 75% vaccine efficacy against infection, and 0% vaccine efficacy against colonization, may lead to 12% model-projected additional reduction in MRSA infection prevalence due to vaccination, while this reduction could reach 37% for vaccination with 75% vaccine coverage and 75% vaccine efficacy against infection in the same average case scenario. CONCLUSIONS: S. aureus vaccination could potentially provide additional reduction of MRSA infection in a hospital setting, on top of reductions from hygiene prevention measures. The magnitude of such additional reductions can vary significantly depending on the level of hygiene prevention measures in place, as well as key vaccine factors such as coverage and efficacy. Identifying appropriate combinations of preventative measures may lead to optimal strategies to effectively reduce MRSA infection in hospitals.