Influenza virosomes: a flu jab for malaria?

The major attractions of vaccines based on viral carriers (vectors) include their immunogenicity without adjuvant and the relative simplicity of their associated production processes in comparison with recombinant protein-based approaches. Two influenza virosomal vaccines – for influenza and hepatitis A – are registered for human use, and the virosome platform is being evaluated as the carrier for a Plasmodium falciparum vaccine that targets both the exo-erythrocytic and erythrocytic stages. Although safe and immunogenic, the first such virosome-based malaria vaccine showed no protection in a Phase IIa clinical trial. Nevertheless, the established safety profile of virosomes and their flexibility with regard to antigen delivery – allowing for antibody induction via the conjugation of peptides and T-cell induction via encapsulation – indicate that they warrant further exploration.