Seasonal influenza causes clinical illness and hospitalization in all age groups; however, conventional inactivated vaccines have only limited efficacy in young children. MF59®, an oil-in-water emulsion adjuvant, has been used since the 1990s to enhance the immunogenicity of influenza vaccines in the elderly, a population with waning immune function due to immunosenescence.
Clinical trials now provide information to support a favorable immunogenicity and safety profile of MF59-adjuvanted influenza vaccine in young children. Published data indicate that Fluad®, a trivalent seasonal influenza vaccine with MF59, was immunogenic and well tolerated in young children, with a benefit/risk ratio that supports routine clinical use. A recent clinical trial also shows that Fluad provides high efficacy against PCRconfirmed influenza. Based on the results of clinical studies in children, the use of MF59-adjuvanted vaccine offers the potential to enhance efficacy and make vaccination a viable prevention and control strategy in this population.