Innovation in active and passive immunisation of people who are immunocompromised: a call to action.

The proportion of the population with immunocompromising conditions, who are at increased risk for complications from infectious diseases, continues to grow. Concurrently, outbreaks due to known and emerging pathogens are increasing. Vaccines are the foundation of infection prevention; however, attenuated immune responses in people who are immunocompromised necessitates innovation in design and delivery strategies. Passive immunisation, whereby the desired immunity is directly transferred to an individual, albeit transiently, could be valuable for patients who are unable to generate robust immune responses with vaccination or infection. However, existing therapies are insufficient. Considerable technical and conceptual advancements in the field of immunology have created unprecedented opportunities for the development of novel strategies and therapies to prevent and treat infectious diseases, and studies in people who are immunocompromised are an important setting in which to apply these developments. In this Series paper, we consider key unmet needs in the areas of vaccinology, monoclonal antibody design, study endpoints, health systems approaches, and policy considerations for people who are immunocompromised.