A novel subunit vaccine based on the viral protein 2 of porcine parvovirus: safety profile in bred pigs at different stages of the reproduction cycle and in offspring

Abstract

Porcine parvovirus 1 (PPV1) viral protein (VP) 2 is the primary antigen responsible for inducing specific protective immunity, so it is a desirable target for development of recombinant subunit vaccines to prevent PPV1 disease. The objective of this study was to evaluate repeated doses of a novel VP2-based PPV1 subunit vaccine, namely ReproCyc® ParvoFLEX, for safety in bred pigs and in offspring under experimental settings. Therefore, the investigation of safety at all breeding stages was evaluated in four independent studies involving: pre-breeding gilts (study A), breeding-age gilts and boars (study B), early and late gestating sows and offspring (study C) and lactating sows and offspring (study D). In all four studies, animals were free from PPV1 based on serology and PCR prior to inclusion. All studies comprised one or two vaccinated groups that received the PPV1 subunit vaccine and a negative control group. Thus, safety was established due to the lack of significant differences between the vaccinated groups and the corresponding unvaccinated (negative control) groups. Gilts, sows and boars were evaluated for local and systemic reactions after vaccination as well as for reproductive performance. The survival rate and average daily weight gain (ADWG) from birth to weaning in offspring was evaluated in studies C and D. Additionally, serology was determined in studies A, C and D. The vaccine was shown to be safe with no relevant significant differences between vaccinated and unvaccinated groups in any experiment. Therefore, repeated doses of ReproCyc® ParvoFLEX were safe in target animals at different stages of the reproductive cycle and in offspring, placing this vaccine as a suitable candidate for mass vaccination programs in breeding herds.

Gilt Vaccination with a Mixed Administration of a PRRS MLV and a PPV1 Subunit Vaccine Protects against Heterologous PRRSV1 Infection and Prevents Detrimental Effects on Piglet Performance

“…Thus, the aim of this study was to evaluate the efficacy of the combined administration of a PRRS MLV vaccine and a PPV1 subunit vaccine in gilts after challenge with a heterologous and pathogenic PRRSV1 strain under controlled laboratory conditions. The safety and efficacy of each vaccine applied individually have been shown in previous studies in the target species [11][12][13][14]. Moreover, the use of this combination has been already reported in the field; the safety and lack of antigen interference of the vaccines were proven in a farm where the circulation of a wild type PRRSV1 virus was confirmed [10].…”

“…KT988004). For the PPV1 subunit vaccine ReproCyc ® ParvoFLEX (Boehringer Ingelheim Vetmedica GmbH, Ingelheim am Rhein, Germany), a manufacturing technology of baculovirus expression system is used to express the viral protein 2 of an isolate from 2001 (strain 27a) [14]. In this case, the PPV1 subunit vaccine was formulated to contain the maximum antigen content per dose to perceive, if any, interference between antigens when mixing vaccines.…”

“…Both ReproCyc ® PRRS EU and ReproCyc ® ParvoFLEX vaccines have been previously demonstrated to be safe and efficacious in several published works [10][11][12][13][14]. In this paper, we expand on our studies on the European-derived PRRS MLV vaccine by determining the OOI and DOI when mixed with the novel PPV1 subunit vaccine.…”

Duration of immunity against heterologous porcine parvovirus 1 challenge in gilts immunized with a novel subunit vaccine based on the viral protein 2

“…Since protection beyond 6 months post-vaccination was not assessed, re-vaccination at regular intervals every 6 month should be recommended when using the present PPV1 subunit vaccine. Regarding the design of the study, a non-vaccinated non-challenged group was not included, as safety evaluation of repeated doses of the present PPV1 subunit vaccine in bred pigs and in offspring has been already assessed under experimental settings [15].…”

Duration of maternally derived antibodies of porcine parvovirus in growing pigs and presence of antibodies in gilts and sows vaccinated with three different parvovirus vaccines

“…While Parvoruvac® (Ceva Santé Animale, Libourne, France) is an inactivated whole virus vaccine based on the virulent Kresse-like strain K22, Eryseng®Parvo (Laboratorios Hipra, Amer, Spain), Suvaxyn®Parvo (Zoetis, Girona, Spain) and Porcilis®Ery + Parvo (Intervet International, Boxmeer, Netherlands) are inactivated whole virus vaccines based on avirulent NADL-2 or NADL-2 like strains [ 16 – 18 ]. In 2020, a novel subunit vaccine based on VP2 of PPV strain 27a (ReproCyc®ParvoFLEX, Boehringer Ingelheim Vetmedica GmbH, Ingelheim/Rhein, Germany) was launched [ 19 ]. In most cases, gilts are vaccinated twice between six and eight months of age and are consecutively revaccinated with a four to six months interval or once in every reproduction cycle [ 5 , 16 , 20 ].…”