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

Abstract

Vaccination against porcine circovirus type 2 (PCV2) is commonly performed in piglets worldwide, and increasingly also in sows. We conducted a literature search and review to assess the potential interference of maternally derived antibodies (MDA) in piglets with vaccination against PCV2. The effectiveness of vaccination was compared to no vaccination in the presence of high levels of MDA (≥8 log2 IPMA titer), as reported in field studies. In total, 13 papers fulfilled the predefined inclusion criteria, allowing up to 24 comparisons per parameter. In the presence of high levels of MDA, vaccinated pigs had, on average, a 20 g/d higher mean daily weight gain and a 34% lower mortality compared to non-vaccinates. The maximum percentage of viremic pigs was reduced by 63% and the maximum viral load in serum was 0.72 log10 PCV2 DNA copies lower. Vaccination at 3 weeks of age was associated with the highest improvements in production parameters and reductions in viremia. Our findings suggest that the vaccination of piglets is effective with respect to production parameters and viremia even in the presence of high MDA, with an age of 3 weeks at vaccination being most beneficial.

Efficacy Studies of a Trivalent Vaccine Containing PCV-2a, PCV-2b Genotypes and Mycoplasma hyopneumoniae When Administered at 3 Days of Age and 3 Weeks Later against Porcine Circovirus 2 (PCV-2) Infection

“…These results are in line with several studies in which a clear interference of MDA in vaccine efficacy in terms of seroconversion has been shown [25,28,29,46,57]. However, a negative MDA effect on humoral immune response in piglets is suggested to be not related to a negative impact on vaccine efficacy except for those cases where MDA titres are high (≥8 log 2 IPMA antibodies) [26]. In addition, PCV-2 vaccines induce not only humoral immunity, but also a cellular immune response [13,30].…”

“…PCV-2 vaccine efficacy in piglets has also been demonstrated in the face of maternally derived antibody (MDA) against PCV-2 [23]. However, the potential interference on vaccine efficacy produced by MDA has not been demonstrated under normal field conditions [24][25][26]. Interestingly, some studies have reported MDA interference with the development of a humoral response after vaccination [14,[27][28][29][30], while others have not [17,20].…”

Descriptive analyses of maternally-derived antibody levels against porcine circovirus 2 (PCV-2) in 3- and 21-day-old piglets from farms of four European countries using different vaccination protocols in sows

“…Indeed, most of the studies available in the literature reporting PCV-2 MDA levels in vaccinated populations were focused on comparing the levels of antibodies present at the time of piglet vaccine administration, mostly around weaning [ 5 – 9 , 12 , 18 ]. The main objective behind such studies was to assess the effect exerted by certain PCV-2 MDA levels on the efficacy of the administered vaccine (reviewed by Poulsen-Nautrup et al [ 3 ]). As far as the authors’ knowledge, this is the first description of PCV-2-specific MDA titres in 3-day-old and 3-week-old piglets derived from sows vaccinated using different strategies.…”

“…PCV-2 vaccination can be applied to sows/gilts, sows and piglets, or piglets. From all these combinations, the most widely used at the field level is the immunization of piglets around weaning, but its application in sows is increasing worldwide [ 3 ]. Vaccination of sows against PCV-2 may seek two objectives.…”

“…In these latter cases, the level of PCV-2-specific maternally-derived antibodies (MDA) at the time of piglet vaccination is paramount as it may potentially influence efficacy (mainly in terms of seroconversion) of piglet vaccination [4][5][6][7][8][9][10][11][12]. The risk of potential MDA interference on vaccine efficacy in terms of average daily weight gain (ADWG) is considered negligible based on published literature [3,12]. However, it is very likely that non-successful experimental or field trials have not been published in peer-reviewed journals.…”