Safety of Porcilis PRRS - Field Trials

To determine the safety of Porcilis PRRS, field trials were done on pig farms in Belgium and France.

Field trial - Belgium

Method
On three farms approximately 200 pigs were vaccinated intramuscularly.

The following was monitored:

• injection sites
• systemic reactions
• temperatures
• weights

Results

1. No local reactions were observed.
2. No systemic reactions were observed
3. In some of the pigs, a slight increase in body temperature was observed at 7 hours post-vaccination. However, this was also observed in the groups receiving a placebo vaccination.

No weight differences were observed between the vaccinated and the unvaccinated groups.

Conclusion
Porcilis PRRS is safe for pigs under field conditions.

Field trial - France

The safety of Porcilis PRRS was tested on PRRS positive commercial farrow-to-finish farms (Pommier, P. et al, 2003).The purpose of this trial was to check absence of vaccine virus spreading from vaccinated piglets (vaccinated at 6-7 weeks) to non vaccinated sows.

In total 15.562 pigs on 10 farms with a high proportion of PRRS seronegative sows (55-100%) were vaccinated with Porcilis PRRS.

Results

• No significant differences in reproduction parameters during the trial period as compared to the reference period (Table 1)
• No virus isolated from 294 piglets (aborted or still born) from 98 litters
• PRRS virus isolated from 2.5% of the vaccinated piglets for up to 6 weeks post vaccination, no virus isolated from older pigs and sows
• Very limited immediate systemic reaction observed, only in 0.4% of the piglets, which in general recovered within a few minutes

Table 1: Mean reproduction parameters for the trial period (V) and the reference period (C)

Period	No. live born piglets per sow	Stillbirth (%)	Abortion (%)	Reproductive failure (%)	No. weaned piglets per sow
V	12.01	7.9	1.2	14.3	10.28
C	11.88	8.2	0.8	16.6	10.35

Conclusion
Vaccination of 6-7 week old pigs with Porcilis PRRS is quite safe for the breeding sows and gilts on the same farm.