LONDON, UK: GSK plc (LSE/NYSE: GSK) has announced an exclusive agreement with Chongqing Zhifei Biological Products, Ltd. (Zhifei) to co-promote its shingles vaccine, Shingrix, in China for an initial three-year period. The partnership aims to significantly extend the availability and access of Shingrix, which has shown 100% vaccine efficacy in preventing shingles in Chinese adults…