@BruceSt22513754 @StopCoronaVir12 @BallouxFrancois @kallmemeg That's exactly right. People were only tested once they got sick during the trials in 2020 when testing was very limited.
Later studies did more testing and produced data on infection and transmission.
@BruceSt22513754 @StopCoronaVir12 @BallouxFrancois @kallmemeg 完全正确。在 2020 年的试验期间，人们只有在生病时才接受检测，当时检测非常有限。
后来的研究进行了更多的测试，并产生了有关感染和传播的数据。