Novel Vaccines and Improvement in Pig Production

By Joel Harris


Editors note:
In the year since the first confirmed cases of Porcine Epidemic Diarrhea (PED) virus occurred in North America, the U.S. swine industry has learned an unprecedented amount of information about the disease in a relatively short amount of time. However, we are far from being able to fully predict the economic ramifications of the disease. Harrisvaccines, is one company that knows that there always will be newly emerging and ever-changing or mutating viruses that affect pork production profitability. Harrisvaccines’ mission is to provide producers and veterinarians with the ability to rapidly respond to these diseases with safe and reasonable expectations of efficacy, in as little as four weeks. BENCHMARK editors discussed the approach that Harrisvaccines takes toward tackling problems like PED with Joel Harris, Head of Sales and Marketing.


Tell us about the process you used to bring the first PED vaccine to market.


Harrisvaccines’ RNA Particle technology is radically different than other vaccine production technology on the market. Instead of growing a virus, we take advantage of state-funded and private diagnostic labs that genetically sequence viruses daily. We take this sequence digitally in a series of letters (A, C, T, and Gs), and synthesize the portion of the virus that we determine will stimulate protection. We identify a gene, the Achilles’ heel of the virus, if you will, and amplify it by several multiples to create the vaccine. The safety profile is extremely high – our vaccines will not cause disease.

PED, like Transmissible Gastroenteritis (TGE), is a coronavirus similar to SARS (Severe Acute Respiratory Syndrome). In 2004, the human vaccine company AlphaVax, that licensed the RNA Particle technology to Harrisvaccines for veterinary use, showed they had been able to protect non-human primates against the disease by expressing the Spike gene of SARS in the vaccine platform.

This gave us a road map for the creation of a PED vaccine. By using this vaccine platform, we are able to insert a gene so that the animal specifically expresses high levels of antibodies after an animal is vaccinated.


How else is this technology being used?


The majority of our exclusive RNA Particle vaccine products are for use in sows. To evaluate their effectiveness, we measure virus-neutralizing (VN) antibody levels (in either experimental animals or samples taken by customers in the field) and production data compiled weekly by producers across the country.

Even now, with over one million PED doses sold and a second-generation product available by veterinary prescription, there is still more analyzing to be done on what an effective or protective VN antibody level is for PED. This type of production data can tell us a lot.

Once a vaccine protocol is implemented, our customer service team helps producers and veterinarians monitor pre/post weaning mortality and cull rates. These metrics have been strongly linked to profitability, as a 1 percent decrease in mortality can equal as much as $1.50 net profit per pig (Dean Boyd, AASV 2012) – and that wasn’t when lean hog market price futures settled at 124.80/cwt (March 20, 2014).

Harrisvaccines gathers these metrics for all of our vaccines (PED, Swine Influenza, PRRS, Rotavirus ABC, Swine Dysentery, Clostridium difficile and Clostridium perfringens) by providing oral fluid kits or “Spit Kits” to producers and utilizing our standing relationships with state and private diagnostic labs for analysis. In this way, we are able to circle back with oral fluid samples and check the diagnosed pathogen against the vaccine

being implemented on the farm when we see increases in piglet mortality. We are then able to make appropriate, customized changes to the farm’s vaccine in as little as four weeks.


What was the first step in developing a PED Vaccine?


When PED was identified in the U.S., we located the Spike gene sequence online from the Chinese strain of PED and electronically inserted it into our production platform process. This Chinese strain was later found to be 99 percent related to the strain occurring in the U.S. By that time, our vaccine was inducing VN antibody levels in experimental pigs, allowing us to release a vaccine for veterinary prescription (iPED) just six months after the first confirmed case of PED. Five months after that, we refined the product and released a second-generation vaccine (iPED+).


What assurance do producers have that using a product like yours will provide a good economic return?


The decision to vaccinate is costly for producers and is not the only way to save a herd. No vaccine is 100 percent effective, especially if it used in a haphazard way without considering herd immunity, or if the animal is overloaded with excessive amounts of feedback. As each month passes, more and more PED cases are confirmed and the ability to use vaccines in a naïve system becomes increasingly difficult.

After the confirmation of PED in Canada at the end of January 2014, the Canadian government approved Harrisvaccines’ second-generation vaccine to be tested in naïve animals in the field through an emergency importation permit process. These systems will work with the Canadian Food Inspection Agency’s Canadian Swine Health Intelligence Network (CSHIN) to monitor clinical signs and production data on a weekly basis to test the effectiveness of the vaccine as the outbreak continues to spread throughout North America.

But as I mentioned, vaccine is only part of the answer. Biosecurity and herd immunity are important in the face of any emerging disease and its impacts on production performance. As modern pig production has transitioned to Isowean production all over the globe, I am reminded of my father, Dr. Hank Harris, and the following message from his book, “Multi-site Pig Production.”

Many factors contribute to the overall level of immunity in the herd (herd immunity), including the pig itself (genetics), weaning age (and if and when the young pig is separated from the adult population), parity distribution, replacement rate of breeding stock, facility design, sanitation, and the nature of and degree of exposure to the infectious agent. The interaction between these factors is what determines the level of immunity in a herd, as well as whether new diseases emerge or old ones re-emerge. Understanding both, this “Catch 22,” between immunity and the level of infectious agents, and the complex interactions of the pig, its environment, and the microbes are critical to producing pigs via the Isowean Principle.

The ability to feed future generations and protect the homeland from foreign animal diseases, similar to, but more devastating than PED, depends on habitual biosecurity measures and rapid response vaccine technology. In this way, the swine industry can have a balanced defense (biosecurity) and offense (targeted vaccines) to stay ahead of ever-evolving and emerging pathogens that damage the bottom line.


Harris oversees all of the daily operations of Harrisvaccines, including research and development, manufacturing, marketing and sales. Harris also negotiates licensing agreements and manages investor relations. He served as a sales accounts manager of Sirrah Bios, a veterinary service company within Harrisvaccines, from March 2008 to January 2009, when he was promoted to Chief Operating Officer of Sirrah. He has served as Head of Sales and Marketing since 2012. Harris earned a bachelor’s degree in economics, with concentrations in international trade and entrepreneurship, at the University of Iowa is 2008.