Effect of Porcine circovirus 2 (PCV-2) maternally derived antibodies on performance and PCV-2 viremia in vaccinated piglets under field conditions

Abstract

Background Nowadays, the most common presentation of PCV-2 is the subclinical infection in piglets after weaning. The success of PCV-2 vaccination is associated with the control of the clinical disease as well as the improvement of production parameters. In consequence, the objective of the present study was to analyse the effect of PCV-2 maternally derived antibody (MDA) levels on vaccine efficacy in piglets vaccinated at three weeks of age with a commercial PCV-2 subunit vaccine. The study was performed analysing a database with 6112 wean-to-slaughter piglets from 4 different European regions. Results Results showed that the use of the vaccine was able to decrease the PCV-2 viremia calculated as area under the curve (AUC = 60.29 ± 3.73), increase average daily weight gain (ADWG = 0.65 ± 0.01 kg/day) and reduce mortality (7%) in vaccinated piglets compared to non-vaccinated ones (AUC of 198.27 ± 6.14, 0.62 ± 0.01 kg/day and 11% respectively). The overall difference of ADWG between both groups was close to 30 g per day ( p < 0.05), also when they were split for low and high levels of MDA titres. Moreover, the animals with the highest ADWG were observed in the group of piglets vaccinated with high or extremely high antibody titres (0.66 and 0.65 kg/day respectively). Considering only animals with extremely high antibody titres, both study groups performed similar, however there was a numerical difference of 10 g/day in favour of vaccinated piglets. Likewise, lack of correlation between ADWG and MDA was observed suggesting that no maternal antibody interference was present with the tested vaccine because the vaccinated animals grew faster compared to unvaccinated control animals, regardless of the level of maternal antibodies present at the time of vaccination. Conclusions The results of the present study demonstrated that the MDA against PCV-2 transferred through the colostrum intake has a protective effect against this viral infection. The vaccine used in the present study (Ingelvac CircoFLEX®) was effective when applied at three weeks of age and was not affected by the level of MDA at the time of vaccination.

Do High Levels of Maternally Derived Antibodies Interfere with the Vaccination of Piglets against Porcine Circovirus Type 2? A Literature Review and Data Analysis

“…From these papers, 10 were excluded based on in-/exclusion criteria. Accordingly, 13 articles [ 4 , 5 , 7 , 8 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ] were finally considered for data collection ( Figure 1 ).…”

“…Consequently, the use of vaccination has shifted the impact of PCV2 on general pig health from a period of worldwide severe clinical outbreaks (1997–2007) to self-limiting subclinical infections with occasional outbreaks. With the widespread vaccination of piglets and the increasing use of PCV2 vaccines in sows, levels of maternally derived antibodies (MDA) and their potential interference with the effectiveness of piglet vaccination have become increasingly important [ 4 ].…”

Revisiting Porcine Circovirus Disease Diagnostic Criteria in the Current Porcine Circovirus 2 Epidemiological Context

“…However, despite the fact that PCV-2 vaccines are very efficient, they are not perfect, and they can prevent clinical disease but no infection [ 74 ]. Therefore, a proportion of vaccinated pigs still become infected during the production period although such infections seem to not impact on the ADWG [ 75 ]. However, whether a particular PCV-2 load threshold in serum is correlated with detrimental effects in pigs with no overt clinical signs at the individual level, is not known.…”

Impact of maternally derived immunity on immune responses elicited by piglet early vaccination against the most common pathogens involved in porcine respiratory disease complex

“…Indeed, high MDA titres against PCV-2 have been shown to impair an active seroconversion after vaccination [ 17 , 21 , 60 , 95 – 99 ]. However, production parameters such as ADWG did not appear to be jeopardized in similar scenarios [ 21 , 93 , 96 , 98 , 100 ], suggesting that interference with seroconversion does not always imply a lack of protection. Of note, Feng et al [ 21 ] highlighted that extremely high titres of MDA at vaccination may interfere with production parameters, although it was considered not economically relevant in practical conditions as it is rare to find such high MDA titres in the field.…”