Comparative safety and efficacy in sows and piglets of a PCV2 vaccine in Philippine field conditions

Objective of these studies were to assess safety and efficacy of a newly developed PCV2 vaccine based on the PCV2d genotype now predominant in many regions (1).

Materials and methods

Trial 1 was performed in a farrow to finish farm owning 500 sows. Twenty-four pregnant sows were allocated according to parity to 3 groups of 11 sows each (groups T and C) and 2 sows (group NV). Sows in group T received the tested vaccine twice around 6 and 3 weeks before expected farrowing (Suigen® PCV2, Virbac, 2 ml for each IM injection). Sows in group C received a booster injection of the PCV2 vaccine they were vaccinated with in previous parities (recombinant vaccine: 2 ml by IM route). Sows in the NV group did not receive any PCV2 vaccine during the study. Piglets issued from each sow received the same PCV2 vaccine (1 ml in group T and 2 ml in group C by IM route) around 6 weeks of age while piglets from NV sows were not vaccinated against PCV2.

PCV2 DNA extracts from lungs and lymph nodes samples (from 2 wasting pigs) were sequenced for PCV2  genotyping.  

Trial 2 was performed in a farrow to finish farm owning  300 sows. One hundred twenty piglets were allocated to  2 groups of 60 each. Piglets were vaccinated against  PCV2 around 6 weeks of age by the tested vaccine in  group T (Suigen® PCV2, Virbac) and by the usual PCV2  vaccine of the farm in group C (subunit vaccine: 1 ml by  IM route in both groups). Pigs were individually weighed  at birth, weaning and finishing in both trials. 

Local and general reactions were checked after  vaccination in both trials as well as mortality cases till  finishing. Categorical data and quantitative data were  compared between groups by Fisher’s exact test and GLM  respectively.

Results

 

Neither local nor general reactions were noticed after injection of the tested and references vaccines in sows and  piglets. Wean to finish mortality rate and ADG were not significantly different between vaccinated groups in both trials  while both criteria were numerically worse in non vaccinated group (trial 1). Moreover, the rate of finishing pigs  weighing less than 80 kg was numerically higher in C group and mean FCR was higher in NV group than in vaccinated  ones (trial 1). 

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PCV2 DNA extract was identified as d genotype in trial 1.

Conclusion

Safety and efficacy of the tested vaccine was confirmed in sows and piglets. PCV2d genotype was isolated for the first time in the Philippines.