Zhifei Biotech announced that the company signed a “Supplementary Agreement to the Exclusive Distribution and Joint Promotion Agreement” with GlaxoSmithKline and GlaxoSmithKline Hong Kong (hereinafter collectively: “GSK”), optimized and adjusted the relevant provisions of the recombinant shingles vaccine procurement plan agreed in the original “Exclusive Distribution and Joint Promotion Agreement” signed on October 8, 2023, and further expanded the company's right to exclusively import, distribute and jointly promote the recombinant shingles vaccine in mainland China. Furthermore, the supplementary agreement further clarifies that the company will exclusively explore and actively facilitate an initial 10-year respiratory syncytial virus (RSV) vaccine commercialization cooperation with GSK in mainland China.