About SAIF Partners SAIF Partners is a leading Asian private equity firm with cumulative assets under management of over $4 billion. SAIF Partners is an active lead investor working closely with its portfolio companies to develop their business both organically and through acquisitions, seeking synergistic cooperation among them, as well as enhancing shareholder value via promotion of good corporate governance and best management practices. Additional Information and Where to Find It This communication may be deemed to be solicitation material in respect of SAIF Partners' nomination of ten director nominees to Sinovac's Board. In connection with such solicitation, SAIF Partners mailed the definitive proxy statement and proxy card to shareholders of Sinovac with respect to the Special Meeting to be held in connection with the election of directors to Sinovac's Board. The definitive proxy statement mailed by SAIF Partners is also filed as Exhibit 1 to its Schedule 13D/A filed on or about June 16, 2025.