Abstract
Porcine Reproductive and Respiratory Syndrome (PRRS) since its appearance in Europe in the early 1990’s has resulted in tremendous economic losses. Under field conditions vaccination is one of the most efficient strategies for the prevention and control of PRRS. The aim of this study is to perform the PRRSV vaccinology regarding current status of commercial vaccines in Europe. There are two types of PRRSV commercial available vaccines in Europe: Killed Virus (KV) or inactivated vaccines and Modified-Live Virus (MLV) or attenuated vaccines. EU KV commercial vaccines provide limited efficacy due to the weak stimulation of the immune system and no effective induction of neutralizing antibodies. However, KV vaccines can induce a strong Cell Mediated Immune (CMI) response. One the other hand, commercial EU MLV vaccines provide effective strain-specific protection, only partial protection against genetically heterologous PRRSV and elicit relatively late humoral and CMI responses which lead to delayed protection. In Europe, the KV vaccination prove to reduce the negative effects of PRRSV in breeding herds, improving their reproductive performance, e.g., increase of farrowing rate and number of live or weaned pigs, reduction of premature farrowing rate, abortion rate and number of mummified and stillborn piglets. The use of commercial MLV vaccines in PRRSV-infected breeding herds leads to improvement of: (a) reproductive performance e.g., reduction of the abortion and return to oestrus rate and increase of the farrowing rate and number of weaners, ( b) the viraemic status, morbidity and mortality rate of piglets and (c) the growth performance of vaccinated pigs. In conclusion, nowadays the use of MLV or KV vaccines in Europe is the most economical tool to control the economic losses of PRRSV infection. However, the development of more efficacious PRRSV vaccines is the significant future goal for PRRSV vaccinology.
Highlights
Porcine Reproductive and Respiratory Syndrome (PRRS) since its first report in the late 1980s in Western Europe (Wensvoort et al, 1991) and North America (Keffaber, 1989) has caused a significant economic impact on the global swine industry (Neumann et al, 2005)
Field studies with some of these nowadays commercial available Killed Virus (KV) vaccines reported that the vaccination has beneficial effects on reproductive performance and litter characteristics of vaccinated sows in PRRS is an RNA virus (PRRSV)-infected farms, where PRRSV circulate among breeding animals (Table 2)
Protection against homologous strain Reduction of post-challenge viremia and completely blocking of PRRSV dissemination to peripheral tissues No clinical symptoms of general or reproductive performance Vaccine strains can replicate in gilts and cross the placental barrier No detrimental effects on the litters and congenitally infected pigs Lack of transmission to non-infected piglets during lactation No clinical symptoms of general or reproductive performance
Summary
Porcine Reproductive and Respiratory Syndrome (PRRS) since its first report in the late 1980s in Western Europe (Wensvoort et al, 1991) and North America (Keffaber, 1989) has caused a significant economic impact on the global swine industry (Neumann et al, 2005). PRRSV strains are divided into two genotypes, the Type I or European (EU) type and Type II or North American (NA) type. For Type II, 9 well-defined lineages have been described (Shi et al, 2010a; 2010b) Both NA (Kapur et al, 1996; Goldberg et al, 2000; Key et al, 2001) and EU (Indik et al, 2000; Oleksiewicz et al, 2000; Forsberg et al, 2002) genotype strains are antigenically and genetically highly distinguishable. The purpose of this present study is to perform the PRRSV vaccinology regarding current status of commercial PRRS vaccines in European market
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
