Autogenous Inactivated MJPRRS Viral Antigen Concentrate Subunit Vaccine

Pork producers continue to search for new tools to combat the economic drain caused by PRRSV. The annual economic impact to US swine production is reported at $560 million (1). No other swine disease in the last three decades has resulted in more headlines, seminars, symposiums, magazine articles, and scientific journal studies.

Many people rely on a vaccination to ward off this disease. Now there is an alternative vaccine production technology. One that utilizes a new, breakthrough process to capture the viral components necessary to increase the antigenic recognition of the vaccine.

MJ Biologics’ PRRSV Vaccine is produced using the Selectigen™ MJPRRS™ Technology, two new patent–pending methods in virus selection and subunit vaccine manufacturing. The process focuses on promoting full protein exposure by harvesting viral antigen components prior to the release of mature virus particles from the host cell. This unique process is able to concentrate viral antigens for incorporating greater antigenic mass in the vaccine.

Development of Autogenous Inactivated MJPRRS Viral Antigen Concentrate Subunit Vaccine

A farrow–to–wean start up sow farm was stocked with PRRSV negative animals. The farm was located in a hog dense area of Minnesota. Within one year, the farm began encountering severe economic losses from PRRSV. Dr Han Soo Joo, DVM, Ph.D., a professor at the University of Minnesota was invited to assist the veterinarians in the search for new approaches to combat the economic drain. Diagnostic work over two years yielded PRRSV from five specific genetic clusters. ORF5 genetic analysis demonstrated 7% or more differences among farm virus clusters. An autogenous vaccination program was implemented using a unique concentrated viral antigen vaccine produced through Selectigen™ MJPRRS™ Technology. A multivalent formulation stabilized the farm, resulting in PRRSV PCR negative pigs in about a month. Over time, an additional strain was added to the vaccine. All sows and replacements were vaccinated with multiple doses of a multivalent autogenous MJPRRS viral antigen vaccine. Satisfactory protection during pregnancy was demonstrated, while other herds in the area continued to experience economic losses.

Viral Antigen Concentrate

Vaccine production focuses on selectively harvesting and concentrating viral antigens from the tissue culture infected with PRRS virus prior to assembling an intact virus. We believe that PRRSV structural proteins are important antigens and the relative amount of PRRSV structural proteins are critical factors. (See Figure 1 Below)

Selectigen™ MJPRRS™ Technology Selectively Concentrates PRRSV Antigens

The Selectigen™ MJPRRS™ Technology captures viral antigen components and extracts them to maximize the viral antigen content in the vaccine. Under the technology, cells are harvested at a point in time to achieve the desirable degree of incubation, harvesting, and inactivation prior to the release of mature virus. As a result, the Selectigen™ MJPRRS™ technology concentrates relatively high viral antigen components in a free form.

Viral Components vs. Viral Particles

Viral Components Increase Antigenic Recognition

The Selectigen™ MJPRRS™ Technology begins with determining a desirable harvest time to maximize viral antigens in the host cell. The selected antigen extraction from tissue culture requires several extra steps compared to the traditional vaccine process to reduce unnecessary protein content in the vaccine. The extra production steps dramatically increase viral antigen concentration in the final product. MJ Biologics believes that inactivated PRRSV component vaccines stimulate the pig’s immune system to recognize more viral antigen. Figure 2 compares viral components and suspended antigen extracted through Selectigen™ MJPRRS™ Technology to fully assembled viral particles.

Antigen Extraction Vaccine Production with Selectigen™ MJPRRS™ Technology

Unique antigen preparation for the highest yields of PRRSV structural proteins in free forms (See figure 3 below)

Selectigen™ MJPRRS™ Technology Process

This patent-pending technology was invented by Dr. HanSoo Joo, professor at the University of Minnesota, College of Veterinary Medicine and exclusively licensed to MJ Biologics.

References:
(1) PRRS losses exceed $560 million per year in United States. [Internet]. 2005, October 1[cited 2006 February 14]. Available from: http://www.porkmag.com/special_reports.asp?pgID=295&ed_id3667
(2) Wagner M., et al. Protection against heterologous PRRSV challenge in pregnant sows immunized with multivalent PRRSV vaccines. In: International PRRS Symposium; 2005 Dec 2–3; St. Louis, MO.

* Field trial data represents results obtained with a specific autogenous killed PRRS viral antigen vaccine formulation. Results may differ using other vaccine formulations.