The Rubella Virus Spike construct comprises at least one E1 component and one E2 component, which are linked together. The E1 component consists of the El envelope protein, whose C-terminal transmembrane region and intravirional domain are removed and whose N-terminus comprises the ectodomain of the El envelope protein. The E2 component consists of the E2 envelope protein whose transmembrane regions and intravirional domain removed and whose C-terminus comprising the ectodomain of the E2 envelope protein.
The C-terminus of the E2 component is connected to the N-terminus of the E1 component by direct fusion or by means of a linker to form an E1-E2 fusion protein.