Official 2018 RB51 Vaccine-Related Illness Story

Miller's Biodiversity Farm RB51 Vaccine-Related Bacteria History

March 18, 2019


On Christmas Eve 2018, the Pennsylvania Department of Agriculture (PDA) placed a quarantine on all raw cattle milk that was not meant for pasteurization at Miller’s Biodiversity Farm (MBF) in Quarryville, PA. This was in direct response to a New York resident who tested positive for the RB51 vaccine-related bacteria and identified MBF as one of their sources for raw dairy products.


It was conveyed that the person recovered weeks before the quarantine was implemented.


While the raw cattle milk was under quarantine, Dr. David Wolfgang, who was the PDA Director for the Bureau of Animal Health and Diagnostic Services (now retired), began aggressive testing on the milk and herd. PDA personnel took initial samples and submitted them to the National Veterinary Services Laboratory (NVSL) in Ames, Iowa.


Samples were analyzed using polymerase chain reaction (PCR) and bacterial culture. Current serology (blood) tests do not detect animals vaccinated with RB51. NVSL is working to develop blood tests that can differentiate animals at high risk for shedding RB51 versus cattle infected with the wild strain of Brucella abortus (B. abortus).


Milk from one cow tested positive for RB51 vaccine-related bacteria in preliminary tests and the farmer immediately removed the suspected cow from rotation. All this happened rapidly. Dr. Wolfgang's team again tested the bulk tank and the results came back negative under PCR testing. PCR results have equivalent sensitivity to culture (blood sample) testing.


Individual samples from the other cows tested negative for the presence of any RB51 vaccine-related bacteria. The PDA lifted the quarantine after multiple negative RB51 vaccine-related confirmatory test results.


RB51 Vaccine-Related Bacteria


We asked Dr. Wolfgang to explain the RB51 vaccine-related bacteria so that non-scientific people could understand it better:


“B. abortus is a serious bacterial infection that can be transmitted from animals (especially cattle) to humans. This bacteria causes very significant disease in people and livestock in many parts of the world. Very long and expensive eradication programs have eliminated this pathogen from all but a few places in the U.S. The bacteria persists in a few wildlife pockets in the West and occasionally is identified in cattle near these pockets. Human and veterinary public health officials continue to work cooperatively to completely eliminate this bacteria from the U.S.


The RB51 vaccine has been a very safe, effective vaccine, and used widely for decades as part of the nationwide control program. The RB51 vaccine contains live Brucella bacteria which have been modified not to cause disease in cattle yet provide protection against the wild strains.


As true B. abortus has been eliminated from many regions, the use of this vaccine has greatly declined. PA and all neighboring states are free of this bacteria. However, some Western states still have regulations in place that require proof of RB51 immunization for cattle moved into the state. For this reason, there can be a small economic incentive for RB51 vaccinated heifers entering market channels. For several years PDA has been recommending that accredited veterinarians evaluate their vaccine protocols. The use of RB51 is strongly discouraged, especially in Jersey cattle and if raw milk (or raw milk products) will be consumed by farm families or offered for sale. RB51 vaccine should only be used when heifers are consigned for sale or movement into states where this vaccine is required.


Although the risk of shedding live RB51 from vaccinated cattle is considered very low, public health officials have been recommending that dairy products from cattle immunized with RB51 be pasteurized. No human cases of RB51 have been associated with pasteurized milk.”


Why did this one cow shed the bacteria?


The cow that caused the RB51 vaccine-related illness is thought to be an animal with a quirky immune system that created the environment for the RB51 bacteria to manifest and then shed, but only sporadically. Since the early 1960’s—when RB51 vaccination began—it is our knowledge that only three (3) cases of the RB51 vaccine and raw milk-related human illness have occurred, including the recent one reported in New York.


Research and Solution Oriented Teamwork


The Real Food Consumer Coalition (RFCC) and the farmer worked closely with the PDA and the Pennsylvania Dept. of Health.


During the quarantine, and in cooperation with the farm, RFCC notified the members of the farm's private membership food buying club multiple times. RFCC provided customers with updates and state health contact information should any of them or their family members wish to get information or seek precautionary testing. This included MBF food club members that have never consumed or ordered raw dairy products.


Miller's Biodiversity Farm, through cooperation with various agencies, provided many invaluable clues and opportunities for scientists to further study the elusive RB51 vaccine-related bacteria.


From the beginning of the PDA’s research regarding this matter, the farmer, using RFCC as a conduit, was transparent and helpful to agencies researching the source of the unfortunate RB51 vaccine-related illness. This incident, although not ideal, has created a professional and transparent collaboration between the PDA, PA Dept. of Health, RFCC, MBF and many other farmers witnessing these occurrences. All parties are learning more about each other’s positions through prevailing mutual respect and an openness to learning.


The cow that was shedding the RB51 vaccine-related bacteria was relocated to a CDC national research facility to live out her life in leisure while providing invaluable information regarding the RB51 vaccine-related bacteria for years to come. She has a new name. Instead of “cow #122,” her new name is now Betsy.


In the news


It appears that most news agencies are more focused on sensationalizing a false “outbreak,” and less focused on accurately reporting the facts of this scenario. The use of the word outbreak regarding this matter speaks volumes about the media’s chosen narrative.


The real story is that agencies, farmers and organizations worked closely together and quickly uncovered unknowns to provide a best case solution for all involved.


A Silver Lining? - Animal Testing and Upgraded Farming Models 


Although nobody wants any illness in the food industry, this event has opened up opportunities to educate farmers about vaccines, testing and trust building throughout the struggling dairy industry. This unforeseen event can hopefully improve some of the deteriorating aspects of the collapsing dairy industry and help create healthy and financially viable socioeconomic trends that will help small farms from becoming unnecessary victims within the dairy industry.

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