Asymptomatic spread has been known for some time now. It’s not new data or new science. It’s been known since late January. (https://www.cnn.com/2020/01/31/health/coronavirus-asymptomatic-spread-study/index.html)
Stop paying attention to CDC and WHO clowns (or other “expert authorities”), and learn to think for yourself. Use that thing inside your head you believe to be a brain.