C4B and cyclic hematopoiesis: In addition, the titer of ani-CV777 is nearly 1.4-fold higher than that of ani-CH/Yinchuan/2021, whereas the ability of some samples to neutralize CH/Yinchuan/2021 is higher than that of CV777, which may be related to the infection of CH/Yinchuan/2021 in pig farms.