Introduction. At present in Europe several commercial PCV2 vaccines are available for use in piglets. One of these is also licensed for sows. Under field conditions, all PCV2 vaccines available are effective, showing decreased mortality and cull rates and significantly improving average daily weight gain (ADWG). The objective of this study was to compare the efficacy of two PCV2 vaccines. Materials and methods. A controlled, blinded and randomized field study was performed on an Italian 420-sow farrow-to-finish farm without PCVD anamnesis. One thousand and fifty piglets, from five consecutive batches, were included in this trial. The piglets were stratified by sex, weight, parity of the sow and randomly allocated to 3 groups. At weaning, each piglet received 0.5 ml Circovac® i.m. (Group A) or 1 ml Circoflex® i.m. (Group B). The pigs in Group C were not vaccinated and kept as control animals. Control and vaccinated piglets stayed intermingled. All animals were vaccinated against M. hyopneumoniae 2 days before PCV2 vaccinations, with a one-shot W/O vaccine. The body weight was determined at 25, 110 and 225 days of age (d). All animals were monitored for clinical symptoms and mortality was recorded during the whole study period. Only batch 3 was chosen for collection of laboratory data in order to assess the impact of vaccination on viral pressure over time. Blood samples were collected monthly and serum samples of Circovac® vaccinated (n=12), Circoflex® vaccinated (n=13), as well as of control animals (n=11) were analyzed by a competitive ELISA. Pooled sera from at least 3 subjects were analyzed by quantitative PCR (qPCR). The ADWG from 25d to 105d, 105d to 220d and from 25d to 220d in the different groups were compared. The comparison was made by assessing any differences between: a) vaccinated subjects (groups A and B) to group C, b) vaccinated with Circovac® or with Circoflex® to non-vaccinated animals (group C), d) vaccinated with Circovac® to animals vaccinated with Circoflex®. Results. In the periods 25-105d, 105-220d and 25-220d the AWDG of vaccinated subjects were significantly higher (respectively: Mann-Whitney U=97767, p<0.01; U=97477, p<0.05; U=92101, p<0.01) than those of the control animals. Both animals vaccinated with Circovac® and those vaccinated with Circoflex® showed ADWG significantly higher (p<0.05) than those of the control group during the three considered periods. The difference between ADWG of group B and group A was not statistically significant for any of the three time periods. The percentage of 25-to-220-day dead pigs and runts: 5.73%, 6.26% and 6.28% for groups A, B and C, respectively, were very similar; however, incidence of underweight pigs was statistically lower in the vaccinated groups. Antibodies titre and serum viral load were statistically lower in vaccinated subjects. Discussion. Compared to the control group, vaccinated animals showed a significant increase of ADWG. Vaccinated animals had a lower titre of PCV2 specific antibodies and the vaccination seemed to reduce the viral pressure in the facilities. This observation is supported by the qPCR data, which showed, that vaccinated animals had a lower serum viral load. No statistically significant difference in the considered parameters was observed between the two vaccines.
Comparative evaluation of two PCV2 vaccines in piglets / Bardini R.; Nigrelli A.; Benaglia P.; Leotti G.; Joisel F.; Faccini S.; Ostanello F.. - STAMPA. - (2011), pp. 167-167. (Intervento presentato al convegno 6th International Symposium on Emerging and Re-emerging Pig Diseases tenutosi a Barcelona nel 12-15 June 2011).
Comparative evaluation of two PCV2 vaccines in piglets
OSTANELLO, FABIO
2011
Abstract
Introduction. At present in Europe several commercial PCV2 vaccines are available for use in piglets. One of these is also licensed for sows. Under field conditions, all PCV2 vaccines available are effective, showing decreased mortality and cull rates and significantly improving average daily weight gain (ADWG). The objective of this study was to compare the efficacy of two PCV2 vaccines. Materials and methods. A controlled, blinded and randomized field study was performed on an Italian 420-sow farrow-to-finish farm without PCVD anamnesis. One thousand and fifty piglets, from five consecutive batches, were included in this trial. The piglets were stratified by sex, weight, parity of the sow and randomly allocated to 3 groups. At weaning, each piglet received 0.5 ml Circovac® i.m. (Group A) or 1 ml Circoflex® i.m. (Group B). The pigs in Group C were not vaccinated and kept as control animals. Control and vaccinated piglets stayed intermingled. All animals were vaccinated against M. hyopneumoniae 2 days before PCV2 vaccinations, with a one-shot W/O vaccine. The body weight was determined at 25, 110 and 225 days of age (d). All animals were monitored for clinical symptoms and mortality was recorded during the whole study period. Only batch 3 was chosen for collection of laboratory data in order to assess the impact of vaccination on viral pressure over time. Blood samples were collected monthly and serum samples of Circovac® vaccinated (n=12), Circoflex® vaccinated (n=13), as well as of control animals (n=11) were analyzed by a competitive ELISA. Pooled sera from at least 3 subjects were analyzed by quantitative PCR (qPCR). The ADWG from 25d to 105d, 105d to 220d and from 25d to 220d in the different groups were compared. The comparison was made by assessing any differences between: a) vaccinated subjects (groups A and B) to group C, b) vaccinated with Circovac® or with Circoflex® to non-vaccinated animals (group C), d) vaccinated with Circovac® to animals vaccinated with Circoflex®. Results. In the periods 25-105d, 105-220d and 25-220d the AWDG of vaccinated subjects were significantly higher (respectively: Mann-Whitney U=97767, p<0.01; U=97477, p<0.05; U=92101, p<0.01) than those of the control animals. Both animals vaccinated with Circovac® and those vaccinated with Circoflex® showed ADWG significantly higher (p<0.05) than those of the control group during the three considered periods. The difference between ADWG of group B and group A was not statistically significant for any of the three time periods. The percentage of 25-to-220-day dead pigs and runts: 5.73%, 6.26% and 6.28% for groups A, B and C, respectively, were very similar; however, incidence of underweight pigs was statistically lower in the vaccinated groups. Antibodies titre and serum viral load were statistically lower in vaccinated subjects. Discussion. Compared to the control group, vaccinated animals showed a significant increase of ADWG. Vaccinated animals had a lower titre of PCV2 specific antibodies and the vaccination seemed to reduce the viral pressure in the facilities. This observation is supported by the qPCR data, which showed, that vaccinated animals had a lower serum viral load. No statistically significant difference in the considered parameters was observed between the two vaccines.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
