Intrauterine vaccination to protect sows, gilts, and piglets from Porcine Epidemic Diarrhea shows promise as an alternative to needles. 
Researchers with the Western College of Veterinary Medicine and the Vaccine and Infectious Disease Organization are exploring intrauterine vaccination as an alternative to needles to improve the safety of personnel and avoid accidents such as needle breaks or skin bruises. 
Dr. Pooja Choudhary, a postdoctoral fellow with VIDO, said most commercial producers breed pigs by artificial insemination so the uterus is easily accessible during each reproductive cycle. 
Dr. Choudhary said the idea is to add the vaccine into semen bags before insemination and deliver it to the uterus where it can generate an immune response. 
When formulating the intrauterine vaccine, the focus is that the vaccine should not affect sperm function and generate a strong antibody response in the gilts, sows, and colostrum. The goal is to achieve a single-dose protective vaccine for mums and piglets. 
“We can formulate vaccines that do not affect sperm function and sow fertility. However, we need a few doses to get the immune response and protective immunity at some level. Therefore, we must improve to get a single-dose vaccine to protect the gilts at the first-time pregnancy.” 
Since 2014 the push by the swine industry to transition to group housing for gilts and sows makes it challenging to handle the animals for routine practices such as vaccination. In addition, most vaccines occur with a needle further challenging tasks for animal workers and stressful for pigs. “Thus our team is exploring an alternate route for vaccination that could work well within current animal husbandry practices. It can improve barn personnel safety and avoid accidents such as needle pricks usually associated with intermuscular or needle-based vaccines.” 
Dr. Choudhary said the goal is to formulate the vaccine against PEDV a viral disease of pigs affecting both newborn piglets and adult pigs. In newborn pigs it can cause watery diarrhea, dehydration, and a high death rate of up to 100 per cent. In contrast, it presents mild symptoms in adult pigs and can cause diarrhea, depression, and reduced reproductive performance. PEDV wasn’t known to be present in North America until identified in the United States in 2013. Since its emergence, it has killed over 8.5 million piglets in the U.S. alone, so we can see how deadly this disease is (and a bunch in Canada). 
According to the Swine Health Information report, the PEDV activity jumped in February this year and interestingly associated more with adult herds rather than finishing herds. To protect against PEDV, they generate antibodies in colostrum and milk during pregnancy and it remains the most effective way to safeguard neonatal suckling piglets. 
“The preliminary research phase will take several years before a product becomes available commercially. However, we are making good progress and getting encouraging results. The next step in the research is to formulate the vaccine into nanoparticles. Hence they are not in direct contact with sperm and potentially can induce a robust immune response and protect both sows and their piglets.” 
Dr. Choudhary said this project excites him. Once established for PEDV can target other swine diseases like PRRS, porcine reproductive and respiratory syndrome virus, another significant infection impacting pregnancy in pigs. •
— By Harry Siemens