简单说，这是个流程，疫苗还没研究出来，如何做1，2，3期。WSJ所可笑家正在adapt。没有进入临床三期。所以，你想多了。

Covid-19 Vaccines Can Be Updated for the Delta Variant. Here’s How.

Scientists are working to adapt the mRNA platform underlying some vaccines to target specific strains of the virus