Vaccination is the most effective way of preventing infectious diseases. Despite the success of vaccines in general, vaccines induce diminished antibody responses and lower protection in the elderly in particular. This could be explained by a defect in the early responses of an ageing immune system. A better understanding of the basic immunological mechanisms that mediate vaccine efficacy is incomplete. Such information is critical and could greatly decrease both the cost and the time to new vaccine development particularly for the geriatric population.