Immunostimulatory adjuvants

A vaccine composition, comprising

• (a) an adjuvant, comprising a chimeric protein or chimeric protein complex, comprising:
• (i) a mutant IL-1β, wherein the mutant IL-1β has an amino acid sequence of at least 95% identity to SEQ ID NO:
• 1,
• (ii) one or more targeting moieties, said targeting moieties comprising recognition domains which specifically bind to an antigen or receptor of interest;
• and
• (iii) a connector between (i) and (ii), the connector being:
• (1) an Fc domain, the Fc domain optionally having one or more mutations that reduces or eliminates one or more effector functions of the Fc domain, promotes Fc chain pairing in the Fc domain, and/or stabilizes a hinge region in the Fc domain that connects (i) and (ii) and/or
• (2) a flexible linker that connects (i) and (ii),
• wherein the mutant IL-1β is characterized by reduced affinity or activity at the IL-1 receptor, as compared to wild-type IL-1β, which is restorable by attachment to the one or more targeting moieties or upon inclusion of the one or more targeting moieties in the chimeric protein complex;
• and
• (b) an antigen which is suitable for inducing an immune response, wherein the antigen is selected from an influenza viral antigen and a 2019-nCoV protein, or an antigenic fragment thereof.