Evaluation of the effects of PEDV vaccine on PEDV naive and previously PEDV exposed sows in a challenge model comparing immune response and preweaning mortality

摘要

Porcine epidemic diarrhea virus (PEDV), a coronavirus, was first recognized in the United States in April, 2013.1 In affected herds it has caused 100% morbidity and 50-100% mortality in suckling [ piglets.2 PEDV has proven to be a very difficult disease to treat or control, and no single intervention strategy has been 100% successful. Colostrum from immunized sows has been found to increase survival rates of PEDV challenged piglets.3 It has been well documented that coronaviruses such as PEDV or transmissible gastroenteritis virus (TGEV) stimulate a strong IgA response in the sow which is passed to pigs via lactogenic immunity.4 The practice of feeding back feces from affected PEDV-positive piglets to sows is effective in stimulating the immune response and lactogenic immunity in sows; however, this practice does present the possibility of continued presence of virulent virus thus continuing disease outbreaks within a herd, significant economic losses, and uncertainty because of variation in immune response in sows.4 There is a need for an efficacious vaccine that can stimulate a protective immune response, can be differentiated from a field strain of PEDV, is safe, and does not pose the threat of prolonging disease outbreaks.