Core Viewpoint - There is a temporary shortage of flu vaccines in several cities in China, including Guangzhou, Xi'an, Changzhou, and Jinan, due to increased demand as the flu season approaches [2][5][7]. Vaccine Supply Situation - Different community health centers report varying levels of vaccine availability, with some lacking the quadrivalent flu virus split vaccine and others the quadrivalent subunit vaccine [2][4]. - The quadrivalent split flu vaccine is experiencing supply tightness due to increased demand, while the quadrivalent subunit vaccine is also in short supply in certain areas [5][10]. - The overall supply of flu vaccines is expected to improve by mid to late November [5]. Manufacturer Insights - Hualan Biological Engineering, the largest flu vaccine producer in China, has an annual production capacity of 100 million doses and is increasing market supply and promotion efforts [5][6]. - Different regions are experiencing varying supply situations, influenced by local demand and inventory levels [6][10]. Demand Factors - The sudden increase in vaccine demand is attributed to the earlier onset of the flu season [7][10]. - The distribution of vaccines is managed by local disease control centers, which order from manufacturers based on local needs, leading to a mismatch in supply and demand timing [7]. Market Dynamics - The flu vaccine market experiences cyclical demand fluctuations, influenced by factors such as consumer willingness to vaccinate and the prevalence of flu strains [10]. - The annual demand for flu vaccines can vary significantly, with years of high demand followed by lower demand in subsequent years [10]. Vaccination Rates and Projections - China's flu vaccination rate remains low compared to the U.S., with only 3.8% during the 2022-2023 flu season, while the U.S. rate was 49.3% [13][14]. - The number of flu vaccine doses issued in China is projected to increase from 70.5 million in 2023 to over 150 million by 2029, with vaccination rates expected to rise to approximately 9% to 15.5% by 2033 [14].