Table 1.

Immune procedure

Group	No.	No. of piglets	Treatment	Day of immunization	Route	Dose (TCID50)
Immunization group	#68	12	Inactivated PDCoV vaccine	40 and 20 days before delivery	Houhai acupoint	4 × 106 TCID50; 3 ml
	#72	10
	#100	12
	#56	14
	#2,736	10
Control group	#5	13	DMEM	40 and 20 days before delivery	Houhai acupoint	3 ml
	#2,750	11

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