Table 1 Field experiment A and B design. In experiment B, the study was conducted in two phases, in which the enrolled animals were split into two treatment groups across phase I or phase II

Experiment A

0

7

21

90

A-PRRSV+PPV1

Mixed vaccine^a

–

–

–

A-PRRSV

PRRS MLV vaccine^b

–

–

–

Experiment B

Phase I

B_I-PRRSV+PPV1

Mixed vaccine

Placebo^c

PPV1 subunit vaccine

PRRS MLV vaccine

B_I-PPV1

PPV1 subunit vaccine^d

PRRS MLV vaccine

PPV1 subunit vaccine

PRRS MLV vaccine

Phase II

201

208

298

B_II-PRRSV+PPV1

Mixed vaccine

Placebo

PRRS MLV vaccine

B_II-PPV1

PPV1 subunit vaccine

PRRS MLV vaccine

PRRS MLV vaccine