Stabilized hepatitis B core polypeptides

A stabilized, chimeric virus like particle (VLP) having an artificial disulfide bond network comprising multiple HBc polypeptides:

• a. wherein at least two amino acids of each of the HBc polypeptides are substituted with cysteine residues that can form interdimer disulfide bonds after the HBc is assembled into the VLP thereby forming the artificial disulfide bond network that stabilizes the VLP;
• b. wherein each of the HBc polypeptides comprises a spike sequence—which has been modified to have a lower negative charge or neutral charge compared to the spike sequence of the wild-type HBc polypeptide at neutral pH;
• and
• c. wherein two HBc polypeptides of (b) are dimerized to form a spike, and wherein the at least two amino acids are selected from the group consisting of P134-P135, P134-N136, P134-A137, and P135-N136 as provided in SEQ ID NO:1 or SEQ ID NO:2 or amino acid pairs at corresponding positions in aligned sequences of HBC polypeptides.