HIV-Like Viruses Contaminate The World’s Vaccine Supply For Pets & Humans, Research Suggest

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A highly concerning study published in Biologicals entitled, “Endogenous retroviruses as potential hazards for vaccines,” reveals that present-day manufacturing processes employed for vaccines have virtually no safe-guards against contamination by surreptitious retroviruses which are present within the master seed stock used to produce them, and which may contribute to, or cause, serious diseases like cancer in exposed populations.


Our Primitive Vaccine Manufacturing Process


Today’s vaccination manufacturing process, both for veterinary and human vaccines, is still dependent on use of live animal and human cells (diploid, fetal) as master seed stock. While so-called inactivated, subunit, and genetically modified vaccines, are now becoming more popular, the present-day CDC schedule still contains live cell based vaccines like the MMR. Also, the veterinary vaccine market and schedule also still contains live cell based vaccines.

Given the use of these cells, it is surprising how little attention is placed on their contamination with endogenous retroviruses. Not only were the original polio vaccines believed to be contaminated with a simian monkey retroviruses, which ultimately led to the emergence of HIV and the AIDS epidemic, but still today the Rotateq vaccine has been identified to contain evidence for infection with not one, but two simian retroviruses of as of yet unknown origin, and pathogenicity.


How Did The Vaccines Become Infected with Retroviruses?


The genomic infrastructure of mammals contain a large number of retroviral sequences (~10% of their DNA), originated from ancient retroviral infections that incorporated into the species’ germlines, and which became benign components of our DNA over the course of hundreds of thousands of years of evolution. However, these “dormant” retroviral sequences can become active again when exposed to cells of other species and a cross-over event — or “xenospecies infection” — occurs, and they infect another species. At this point, these retroviral sequences can lead to infection and/or other deleterious events.


How would such a cross-over event occur?


Both the vaccine manufacturing process, as well as the administration of vaccines containing cell components from species that are injected into different ones, makes for a perfect opportunity for such an event. The study makes mention of this possibility:


“Many live attenuated vaccines for animals are manufactured by using cell lines from animals, which are known to produce infectious ERVs; however, the risks of infection by ERVs from xenospecies through vaccination have been ignored. This brief review gives an overview of ERVs in cats, the potential risks of ERV infection by vaccination, the biological characteristics of RD-114 virus (a feline ERV), which possibly contaminates vaccines for companion animals, and the methods for detection of infectious RD-114 virus.


How did we first come to understand the dangers of xenospecies infection with ERVs?


The study mentions a classical example of ERV dangers: namely, harms caused by xenotransplantation of pig organ or tissues into humans:

Technical innovation of animal engineering enables us to develop genetically engineered pigs for the purpose of xenotransplanting pig organs or tissues to humans; however, pigs have replication- competent ERVs, termed porcine ERVs (PERVs) [17]. The discovery of PERVs able to infect human cells led to the halt of the clinical trials of xenotransplantation, and the risks of PERVs in xenotransplantation have been investigated extensively.


Other historical examples of infectious ERVs mentioned are:

  1. ERVs from AKR mice induce lymphoma in their hosts [11].

  2. An ERV from Asian rodents infected Gibbon apes and induced lymphoma [19].

  3. A retrovirus emerged in koalas in Australia about two hundred years ago, and endogen- ized [19]. The virus, named koala retrovirus, induces neoplastic diseases and immune suppression in the new host.

  4. In humans, a novel gammaretrovirus was discovered recently in patients with prostate cancer [21]. This virus was closely related geneti- cally to the xenotropic murine leukemia virus (X-MLV) and designated as xenotropic murine leukemia virus-related virus (XMRV).  


Additional examples are:


“In the veterinary science area, at least mice, pigs, cats and chickens have infectious ERVs. Many live attenuated vaccines for animals are manufactured by using cell lines from these animals. In addition, several live attenuated vaccines are manufactured by using cells which are known to produce infectious ERVs; however, the risks of infection by ERVs from xenospecies have been ignored.”


The Cat Is Out of the Bag

Since 1991, it has been known that feline vaccines can cause a malignant tumor to form known as a sarcoma. Known as  vaccine-associated sarcoma (VAS) or feline injection-site sarcoma (FISS), the phenomenon was first recognized at the University of Pennsylvania School of Veterinary Medicine, and highlighted in a paper titled, "Do injection site reactions induce fibrosarcomas in cats?1

Could feline retroviruses be a contributing cause? 

The study acknowledged that there are at least three kinds of feline ERVs that have been identified in the cat genone: 

“At least two ERVs, endogenous FeLV and RD-114 virus, are present in the cat genome. In addition to these ERVs, two additional ERVs have been reported. Bonner and Todaro reported that cats  may contain a third group of ERV, distantly related to the primate virus MAC-1 [2]. Haapala et al. also reported a novel endogenous retrovirus which is related to RD-114 virus [6]; however, no further studies have been performed on these ERVs. There are about 20 copies of endogenous FeLV in the cat genome, and at least two loci have ORF encoding Env [7]. Extensive genetic analyses revealed that there is no infectious locus in the cat genome. On the other hand, all domestic cats (Felis catus) have an entire RD-114 genome and sometimes the virus is produced spontaneously or induced in vitro from feline cells by several chemical reagents [14].

The RD-114 virus is of special concern because is found within a wide range of vaccines for canine vaccines, as well as “off label” use in zoos for other exotic animals, and is of course also potentially re-infecting cats whenever administered to them.

It is of considerable importance to note that the so-called “feline” RD-114 virus was first isolated from a human tumor cell line that was ‘passaged,’ or previously exposed, to fetal cats. Presumably, the fetal cat cells contained the RD-144 provirus which when exposed to the human tumor cells provided it an opportunity to “cross over,” i.e. become xenotropic. Considering the close proximity of humans to domesticated cats, or animals like dogs that are now vaccinated and presumably infected with RD-114 virus, there is a clear human health risk, as the precedent for its human specific infectivity was set from the moment the virus was discovered:

“RD-114 was first isolated from a human tumor cell line (RD cells) derived from a human rhabdomyosarcoma after passage through fetal cats, and is thought to be xenotropic, i.e., RD-114 virus does not productively infect feline cells. However, RD-114 virus is known to infect several feline cell lines [1,4] in addition to cell lines from xenospecies such as humans and dogs; therefore, RD-114 virus is polytropic, but is not strictly xenotropic in vitro. In human cell lines, RD-114 virus interferes with BaEV, simian retroviruses 1, 2, 3, 4 and 5 (primate betaretroviruses), avian reticuloendotheriosis virus, and duck spleen necrosis virus; therefore, these retroviruses are considered to utilize the same receptor in human cells. In 1999, two groups independently identified the receptor for this large interference virus group [13,18]. “

Next the researchers addressed the problem with, “Potential contamination of vaccines for companion animals by RD-114 virus,” stating that the only way the problem would be eliminated is if non-feline cells were eliminated from the vaccine production process. The researchers concluded:

As long as feline cells are used to produce vaccines, there is a risk that infectious RD-114 virus contaminates live attenuated vaccines. Because RD-114 virus productively infects cells from cats and dogs, the virus can infect these animals in vivo. Since certain ERVs infect new host species and induce diseases, the potential risks of infec- tion by ERVs in humans and animals should be reconsidered. Recently, we developed a sensitive assay system, LacZ marker rescue assay, to detect infectious RD-114 virus. We are currently investigating the presence of infectious RD-114 virus in commercial live attenuated vaccines for companion animals.”

ERVS Infecting Not Just Cats, But Dogs, and Humans

While this study focused on feline ERVs, the problem of vaccine contamination, as well as other biologicals, is widespread. In another 2013 study the researchers mentions the findings of UK and Japanese researchers who confirmed the presence of a feline ERV in both cat and canine vaccines:

Recently, Japanese and UK research groups found that several feline and canine vaccines were indeed contaminated with infectious RD-114 virus. This was the first incidence of contamination of ‘infectious’ ERVs in live attenuated vaccines. RD-114 virus replicates efficiently in canine cell lines and primary cells. Therefore, it is possible that RD-114 virus infects dogs following inoculation with contaminated vaccines and induces proliferative diseases and immune suppression, if it adapts to grow efficiently in dogs. In this review, we summarize the incidence of con- tamination of RD-114 virus in live attenuated vaccines and potential risks of infection with RD-114 virus in dogs.

But the problem extends beyond animals. The study also mentions the likelihood of ERVs in human vaccines such as MMR:

“In previous studies, it was reported that MMR vaccines (measles, mumps and rubella vaccines) and yellow fever vaccines that were propagated in chicken embryos were contaminated with endogenous avian leukosis viruses (ALVs) and endogenous avian retroviruses (EAVs), which originate from chicken embryonic fibroblast substrates [16, 45].

The truth is that any vaccine produced through animal, insect, and even plant cells, carries a risk for serreptitious viral contamination. The fact that present-day vaccination manufacturing processes were developed before the discovery of reverse transcriptase, helps to explain how such a profound lack of oversight and understanding of retroviral contamination is operative today within the global vaccine agenda. The safety issues, which could not have been foreseen at the relatively primitive state of scientific learning the founders of modern day vaccinology and immunology were at, continue to haunt those both at the giving and receiving end of the agenda. Thankfully, the research is finally coming into the light of day. To learn more about this modern day “plague,” read Judy Mikovitz work on the topic, or listen to our interview on Fearless parent.


Hendrick M, Goldschmidt M (1991). "Do injection site reactions induce fibrosarcomas in cats?". J Am Vet Med Assoc199 (8): 968. PMID 1748617.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of GreenMedInfo or its staff.
Sayer Ji
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