We don't have a crystal ball, so the way it works is scientists from around the world come together every year and make their best guess at which strains of the flu virus, because there are a bunch of them, should be included in the flu vaccine based on which are the most dangerous or which are the most prevalent meaning which are the ones that are circulating so we don't get it right 100% of the time.
我們沒有水晶球,所以它的工作方式是來自世界各地的科學家們每年聚集在一起,並做出他們最好的猜測,根據哪些是最危險的或哪些是最流行的意思是哪些是流通的流感病毒株,應該包括在流感疫苗中,所以我們不會100%的正確。