Tag Archives: animal testing

Animal Testing. Is it really a polarised debate?

I was recently contacted by a student who had an assignment to report both sides of a contentious issue, and she’d chosen animal research.

To her, there were two sides to the debate – a simple yes or no to research. Yet, as I explained to her, it is not a genuinely two-sided argument.

To understand why, we need to look at the basis of the hardline anti-vivisection viewpoint that no animal should be used in an experiment. This is the position taken by most animal rights groups around the world, from PETA and the National Antivivisection Society, to Cruelty Free International and Animal Aid. The polar opposite of this viewpoint is that animals should always be used in experiments, yet this is never what has been argued by those in favour of experiments in the UK.

Are debates like this really between polar opposites?

Are debates like this really between polar opposites?

To understand the history of the issue, animal research really kicked off in the mid to late 1800s. In 1875, there was a Royal Commission which examined the necessity of using animals, at which scientists including one Charles Darwin gave evidence.

In 1876, on the basis of the Royal Commission, Parliament passed the Cruelty to Animals Act, 1876, which demanded that all researchers using animals, as well as each experiment, must be licensed.. There were relatively few experiments even proposed at the time, so the President of the Royal Society was asked to justify the scientific validity of each one. Special protections were afforded to dogs, cats, primates and horses which ensured that they could not be used if another species would suffice.

As time has gone on, the law around animal research has been tightened and finessed. In 1986, the Animals (Scientific Procedures) Act made it explicit that animals could not be used if there was an alternative method and in 1998 it became illegal to test cosmetics or their ingredients.

Still, however, the principal of only allowing research conditionally remained at the heart of UK animal research. In order to conduct an animal experiment, researchers need a series of licenses from the Home Office. The experiment has to pass two tiers of ethical review and prove why there is no alternative to using an animal.

If we were to transpose this ethical review system for experimentsto using animals for food we would say ‘it can be ethical for a person to eat a chicken if, for instance, they are malnourished’. Each person who was hungry would have to apply to eat the chicken, explaining also why they couldn’t eat anything else, and their application would be considered by an ethics committee before being rubber-stamped by the Home Secretary.

The key thing here is that this system is different from saying ‘it is always acceptable to use an animal’, which is the polar opposite viewpoint of ‘it is never acceptable to use an animal’.

The ethical difficulty of saying that it is never acceptable to use an animal is that it underplays the value of human and animal medicines which have derived from animal experiments. Indeed, some campaigners wilfully attempt to rewrite medical history to remove the role of animals from key discoveries, but how could you remove dogs from the discovery of insulin? How do you make a drug based on a mouse hormone without a mouse?

Individuals can be against all animal experiments if they want, but they have to acknowledge the harms associated with their worldview. It is similar to anti-vaxxers: it’s your lookout if you don’t want to vaccinate your child, but let’s be clear that you are placing them and others at risk.

Researchers are motivated to act because the victims of disease are not hypothetical. They are the children on the wards of Great Ormond Street hospital, they are people dying in sub-Saharan Africa, they are wild animals, they are your pets, they are your family. The suffering is already happening. Standing idly by and watching them suffer is not a kindness, it’s a negligence.

There are other important subtleties which are lost with a simplistic yes/no approach to animal research. For instance, what do we mean when we say ‘research’? Are we talking about brain surgery, or a blood sample? We know, for example, that some 27% of experiments are below the threshold for suffering; so have suffered less than if they’d received an injection. The degree of suffering is essential to judging the value of an experiment as the costs relative to the benefits are essential to determining value. If I’m offered a ‘procedure’ by a doctor, I’m going to need to know if we’re talking about a blood test or an amputation before deciding whether to go ahead with it.

I think it was worth using animals to develop the badger TB vaccine and the vaccines I give my cat. I think it is worth using a mouse to make a breast cancer drug, because I think the tens of thousands of women who are diagnosed with the condition every year are capable of suffering in ways the mouse cannot. For example, they may be consumed by worry for their children, whereas mice are liable to consume their children. The woman and the mouse are not morally equal except by the most superficial of measures.

However, I want to know that each experiment has gone through rigorous ethical review. I want to know that it is worthwhile. If it is not, I, somebody who is notionally ‘for’ animal research, would agree with those opposed to it. This can only means one thing – the definition of ‘against’ animal research is correct, but the definition of someone ‘for’ it is lacking. Those who identify as being against animal research are generally against all animal experiments. Those who identify as supporting animal experiments are generally only supportive given strict conditions (based on regulation, purpose etc).

I also want to see alternatives to animals testing and research continue to be developed. Animals may well be the best model we have for many bits of research, but I want better. So should you. These would have the potential to be cheaper, and even more reliable.

It’s true that there’s little dialogue between the biomedical community and the now established anti-research lobby and this isn’t surprising since they are effectively having different conversations. The biomedical community is figuring out how to improve animal welfare and is engaged in an ongoing harm/benefit debate. The demands of those opposed to animal research are effectively too uncompromising, too unreasonable, too damaging to the public good to be accommodated.

Their policy asks are all about banning research, which merely sends it abroad (often to places with lower regulatory standards), rather than doubling down on developing alternatives to animal studies which will be the only realistic way to reduce the overall number of animals used in research.

So are pro-research and anti-vivisection viewpoints, polar opposites?

Animal Rights perspectivesNo. The research community is supportive of measures to improve animal welfare while recognising the importance of balancing it with the needs of those suffering from disease worldwide.

Indeed agreement between researchers and the animal rights movement can be found through investment and development of alternative technologies, while accepting that some animals will continue to be needed in the foreseeable future. If only we could focus on that, instead of engaging in a public bun fight between two sectors which aren’t even having the same conversation.


Caveat Emptor

A current USDA case involving a major antibody producer underscores the need for the research community to demonstrate its commitment to high standards of animal welfare.

On August 18-20, 2015, Santa Cruz Biotechnology, Inc. (SCBT) went before Administrative Law Judge Janice Bullard in Washington to rebut charges of Animal Welfare Act (AWA) violations at its California antibody production site. The hearing was supposed to conclude on August 21. However, according to an account of the hearing posted by the Animal Welfare Institute (“Key Hearing in DC from August 18 to August 20”), the proceedings were suspended on the last day and the parties were given until September 30, 2015 to negotiate a settlement. As of this writing, no settlement agreement has been reached. Therefore the allegations against SCBT remain just that—allegations: Final judgment must be withheld until the legal proceedings are concluded. Nevertheless, the seriousness of the USDA’s charges against SCBT demands attention.

Why antibodies matter

Antibodies play an increasingly important role in both clinical medicine and research. The immune system generates antibodies when it detects a foreign protein. Antibodies are proteins that tag these “invaders,” enabling other immune cells to find and destroy them. Because each antibody targets a single protein, they also have many useful applications. Antibodies can be used to diagnose and treat diseases, such as cancer and autoimmune conditions including rheumatoid arthritis and inflammatory bowel disease. Just this past August the U.S. Food and Drug Administration approved the antibody-based drug Repatha (evolocumab), the second in a new class of drugs that can lower cholesterol dramatically by targeting a specific protein.

Antibodies are also widely used in research to detect specific proteins in blood or tissue:

Yates lab neurotransmitter photo

Antibodies “light up” a neurotransmitter in this sample of brain tissue. Yates laboratory, University of Pittsburgh

Antibody production is a multi-billion dollar industry, and SCBT is a major player.

Making antibodies

Antibody production starts by injecting animals with the protein to be tagged. One production method involves collecting blood from animals injected with the protein and then extracting the antibodies. This method produces polyclonal antibodies that are comprised of a collection of immune cells.

Another method uses hybridoma technology which produces monoclonal antibodies that consist of only one type of immune cell. This method also begins by injecting an animal with the protein to be tagged. The next step is to remove an initial batch of antibody- producing cells from the animal’s blood and fuse them with a harmless cancer cell to produce a cell line that can generate the desired antibody in the lab. César Milstein and Georges J. F. Köhler shared the 1975 Nobel Prize in Physiology or Medicine for developing this methodology.

When performed properly, the creation of antibodies using either of these methods causes minimal pain or distress to animals.

SCBT produces antibodies with various animals including goats and rabbits, species regulated under the AWA. The USDA sends inspectors at least once a year to visit all facilities that conduct research, teaching, or testing with regulated animal species to ensure their compliance with the AWA.

In a formal complaint filed August 7, 2015, the USDA accused SCBT of “repeated failures to provide minimally-adequate and expeditious veterinary care and treatment to animals” (2015 complaint, paragraph 5). USDA said further that the company had “demonstrated bad faith by misleading APHIS personnel about the existence of an undisclosed location” where goats were housed (2015 complaint, paragraph 6).

SCBT history of non-compliance citations

This was not the first time SCBT has been cited for AWA compliance issues. According to the August 7, 2015 complaint, in July, 2005, the company paid a $4,600 penalty to resolve allegations of AWA violations from 2002-2004 (2015 complaint, paragraph 7). Seven years later, on July 19, 2012, USDA filed a complaint against SCBT alleging the following:

  • SCBT failed to “establish and maintain programs of adequate veterinary care.” (2012 complaint, paragraphs III. B.-C based on findings from a July 13, 2010 inspection; 2012 complaint, paragraphs IV. C.-D, based on findings from a February 8, 2011 inspection; and 2012 complaint, paragraph VI. B. 5, based on findings from a March 6, 2012 inspection);
  • During the March 6, 2012 inspection, the inspector cited SCBT for not only having “failed to establish and maintain programs of adequate veterinary care under the supervision and assistance of a doctor of veterinary medicine,” but also having “failed to provide veterinary care to animals in need of care.” (2012 complaint, paragraph VI. A);
  • On July 13, 2010, the USDA inspector cited SCBT for animal care staff who were not properly trained. (2012 complaint, paragraphs III. A.-B. and E.1);
  • On July 24, 2007, the USDA inspector cited SCBT for improper handling of animals. (2012 complaint, paragraph II.D.1.-2).

The 2012 complaint also noted various shortcomings of SCBT’s institutional animal care and use committee or “IACUC.” According to the AWA, the IACUC is required to “assess the research facility’s animal program, facilities, and procedures,” including semi-annual inspections of the facilities that identify and report “significant deficiencies.” (9 C.F.R. section 2.31 (c) (1-3)) A significant deficiency is defined in 9 C.F.R. section 2.31 (c) (3) as a problem that “is or may be a threat to the health or safety of the animals.” The IACUC is also required to review and approve animal use protocols before the research commences, to review and approve significant changes to ongoing protocols, and to ensure that animal pain and distress are minimized.

The 2012 complaint alleged these problems with SCBT’s IACUC:

  • The AWA requires the IACUC to determine that the principal investigator had considered alternatives to potentially painful procedures and failure to ensure that the animals’ pain and distress would be minimized by providing pain relieving drugs unless there was scientific justification to withhold them. (9 C.F.R. 2.31 (d) (1) (ii)) Alleged failures of the SCBT IACUC to do so were noted in the July 24, 2007 inspection (2012 complaint, paragraphs II. B.-C); the February 8, 2011 inspection (2012 complaint, paragraphs IV.A.-B); and the March 6, 2012 inspection (2012 complaint, paragraph VI. B. 2);
  • The AWA requires the IACUC to review and approve significant changes to an ongoing activity. (9 C.F.R. 2.31 (c) (7)) On March 6, 2012, the USDA inspector cited SCBT for an alleged failure of its IACUC to review significant changes. (2012 complaint, paragraph VI.B.1);
  • The AWA requires the IACUC to determine that animals are housed in conditions appropriate for their species. (9 C.F.R. 2.31 (d) (1)) On March 6, 2012, the USDA inspector cited SCBT for an alleged failure of its IACUC to ensure appropriate housing for animals at the facility. (2012 complaint, paragraph VI. B. 3)
Photo credit: Dan Coyro -- Santa Cruz Sentinel

Photo credit: Dan Coyro — Santa Cruz Sentinel

2014 hearing delayed

The 2012 complaint was to have been adjudicated in 2014, but the hearing was called off two weeks before it was scheduled to take place. According to a July 1, 2014 notice issued by Administrative Law Judge Jill S. Clifton, the hearing was cancelled to give SCBT and USDA “ample time to meet to further their attempts to settle the case.” However, no resolution to the allegations in the complaint was announced, and during subsequent visits, USDA inspectors identified more alleged AWA violations at SCBT.

On November 4, 2014, USDA filed a second formal complaint listing alleged violations found during 7 inspections between September 26, 2012 and April 22, 2014. The second complaint charged SCBT with having “failed to allow APHIS officials to inspect” a barn known as Lake Ranch/H7 “from at least March 6, 2012, through October 30, 2012.” (2014 complaint, paragraph III). This complaint also listed additional instances of failures to provide adequate veterinary care based upon findings from inspections of October 31, 2012 (2014 complaint, paragraph IV. B), December 18, 2012 inspection (paragraph V); and February 20, 2013 (paragraph VI).

The 2014 complaint also included these allegations:

  • The AWA requires the IACUC to ensure that the proposed activities or significant changes in ongoing activities “will avoid or minimize discomfort, distress, and pain to the animals.” (9 C.F.R. 2.31 (d) (i)) On September 26, 2012, the USDA alleged that SCBT’s had failed to execute this requirement. (2014 complaint, paragraph II. A);
  • The AWA requires the IACUC to “review and approve, require modifications in (to secure approval) or withhold approval of proposed significant changes regarding the care and use of animals in ongoing activities.” (9 C.F.R. 2.31 (c) (7)) Alleged failures of the SCBT IACUC to do so were noted during the inspections of October 31, 2012 (2014 complaint, paragraph IV.A); May 14, 2013 (paragraph VII); and April 22, 2014 (paragraph IX.A.-B);

The 2014 complaint further listed problems with the housing, food, and water provided to animals. These problems were noted in the September 26, 2012 inspection (cited in paragraph II. C. 1-4 of the 2014 complaint as alleged violations of 9 C.F.R. Sections 3.125 (a), 3.129 (a), 3.131 (a) and (d)); in the October 31, 2012 inspection (cited in paragraph IV.C. as alleged violations of 9 C.F.R. Sections 2.26, 2.100 (a), and 3.131 (c)); in the September 10, 2013 inspection (cited in paragraph VIII.1 as alleged violations of 9 C.F.R. Section 3.127 (a)); and in the April 22, 2014 inspection (cited in paragraph IX. C.1-3 as alleged violations of 9 C.F.R. Sections 3.56 (a), 3.54 (a), and 3.129 (a)).

USDA’s latest complaint

The third USDA complaint was filed August 7, 2015 and reported by the Santa Cruz Sentinel under the headline: “Santa Cruz Biotech faces third USDA complaint alleging animal mistreatment.” As noted above, this complaint asserted that the company had “demonstrated bad faith by misleading APHIS personnel about the existence of an undisclosed location where respondent housed regulated animals.” (2015 complaint, paragraph 6) It also alleged that SCBT had “repeated[ly] failure[d] to provide minimally-adequate and expeditious veterinary care and treatment to animals.” (paragraph 5) In support of this allegation, subparagraphs 8. a.-n. of the complaint describe 14 instances between 2011 and 2015 where USDA inspectors observed individual goats that appeared to be in poor health and lacking appropriate veterinary care. Several of these goats were thin, appeared anemic or seemed to be suffering from infections (subparagraphs 8 a., b., c., d., g., j., k., l., and m.), while others had wounds or other injuries (subparagraphs 8.e., f., and i.).

These were two of the most serious cases:

  • “Respondent failed to provide adequate veterinary care to a goat (#12267) that sustained a rattlesnake bite on April 28, 2012, and following initial treatment, the goat’s condition did not improve, and the goat was not given any further treatment until its death. Specifically, the goat developed a visibly swollen jaw and chest and draining lesion and experienced a 23% weight loss (24 pounds) between April 28 and May 9, 2012. By APHIS’s inspection on May 24, 2012, the goat was observed to be unable or unwilling to close its mouth, which, in conjunction with the goat’s other visible conditions, indicated that the goat was unable to eat normally. On June 10, 2012, the goat was observed to have labored breathing, but was not euthanized June 11, 2012.” (2015 complaint, sub paragraph 8.f.);
  • “Respondent failed to provide adequate veterinary care to a goat (#21135) that had been diagnosed with urinary calculi [kidney stones] and treated with ace promazine. On July 7, 2015, at approximately 10:30 a.m., APHIS inspectors found the goat in a depressed posture, unwilling to walk, and breathing heavily. Respondent had no veterinarian available to attend to this animal: the respondent’s ‘on-site’ veterinarian was on vacation, and respondent’s staff could not contact respondent’s attending veterinarian, or any other veterinarian who could provide emergency care. By 3:30 p.m., the goat was agonal [gasping for breath], suffering and in distress. Respondent failed to follow its own ‘Standard Operating Procedure’ for emergency goat euthanasia, which requires veterinary approval for euthanasia. As no veterinarian was available, respondent’s staff used a captive bolt gun alone (without a sedative or secondary euthanasia injection,) to effect euthanasia of the goat at approximately 4:15 p.m.” (2015 complaint, subparagraph 8.n.).

As of this writing, there has been no judicial resolution of the alleged AWA violations by SCBT. That is to say, neither a settlement between USDA and SCBT nor a continuation of the administrative hearing has been announced.

Animal welfare matters

On February 14, 2014, Cat Ferguson wrote in The New Yorker about alleged animal welfare problems at SCBT, “Valuable Antibodies at a High Cost”. On September 25, 2015, science writer Meredith Wadman published an opinion article in the San Jose Mercury News about the 4-day hearing the previous month. In “No excuse for cruelty to goats raised for medical research,” Wadman opined that researchers were “the only constituency that Santa Cruz cares about,” and urged them to “weigh in” using their purchasing power. According to Wadman, Matt Scott of the Carnegie Institution for Science and Pamela Björkman of the California Institute of Technology have stopped buying antibodies from SCBT. Wadman concluded by asking, “Is it too much to ask other scientists to follow suit?”

Testimony from USDA Veterinary Medical Officer Marcy Rosendale was reported in an account of the August 18-20, 2015 hearing posted by the Animal Welfare Institute. According to this report, Rosendale said she had not observed the same number of animal welfare problems she found at SCBT at other antibody production facilities she had visited.

There is growing recognition that to ensure the rigor of their work, scientists need more information about the antibodies they use actually, i.e., technical specifications such as the what part of the target protein the antibody binds to. Perhaps it is also time to pay more attention to how those antibodies are produced.

USDA inspections are a matter of public record, but meeting the requirements of the AWA should only be the beginning. Antibody producers should be encouraged to take additional steps to affirm their commitment to animal welfare, such as by seeking independent accreditation of their production facilities through AAALAC. The point is that researchers and antibody producers alike must find tangible ways to demonstrate a commitment to high standards of animal care.

Alice Ra’anan and Bill Yates

Previous posts about SCBT and antibodies:



USDA documents:

USDA – 1st SCBT complaint 19 July 2012

USDA – 2nd SCBT complaint 4 Nov 2014

USDA – 3rd SCBT complaint 7 Aug 2015

Nobel Prize 2015 – Protecting People against Parasites!

The 2015 Nobel Prize in Physiology or Medicine has been awarded to scientists whose research has led to therapies that have saved hundreds of millions of people around the world from parasitic diseases that can otherwise cause disability and death.

William C. Campbell and Satoshi Ōmura shared one half of the award “for their discoveries concerning a novel therapy against infections caused by roundworm parasites”, while Youyou Tu was awarded the other half “for her discoveries concerning a novel therapy against Malaria”.

Portraits of the winners of the Nobel medicine prize, shown on a screen at the ceremony in Stockholm. Photograph: Jonathan Nackstrand/AFP/Getty Images

Portraits of the winners of the Nobel medicine prize, shown on a screen at the ceremony in Stockholm. Photograph: Jonathan Nackstrand/AFP/Getty Images

In the press release announcing the award the Nobel Assembly at the Karolinska Institute highlighted the impact of the therapies that were developed thanks to the work done by these three scientists, Avermectin in the case of William C. Campbell and Satoshi Ōmura, and Artemisinin in the case of Youyou Tu.

The discoveries of Avermectin and Artemisinin have fundamentally changed the treatment of parasitic diseases. Today the Avermectin-derivative Ivermectin is used in all parts of the world that are plagued by parasitic diseases. Ivermectin is highly effective against a range of parasites, has limited side effects and is freely available across the globe. The importance of Ivermectin for improving the health and wellbeing of millions of individuals with River Blindness and Lymphatic Filariasis, primarily in the poorest regions of the world, is immeasurable. Treatment is so successful that these diseases are on the verge of eradication, which would be a major feat in the medical history of humankind. Malaria infects close to 200 million individuals yearly. Artemisinin is used in all Malaria-ridden parts of the world. When used in combination therapy, it is estimated to reduce mortality from Malaria by more than 20% overall and by more than 30% in children.

For Africa alone, this means that more than 100 000 lives are saved each year.

The discoveries of Avermectin and Artemisinin have revolutionized therapy for patients suffering from devastating parasitic diseases. Campbell, Ōmura and Tu have transformed the treatment of parasitic diseases. The global impact of their discoveries and the resulting benefit to mankind are immeasurable.

Animal research played a key part in the development of these therapies, as the Nobel Prize press release has pointed out.

Image: NobelPrize.org

Image: NobelPrize.org

In the case of Avermectin, after  Satoshi Ōmura had identified a series of bacterial cultures that produced a variety of antimicrobial agents, including the bacteria Streptomyces avermitilis which  showed promise against parasitic roundworm infection in mice, in 1979 William C. Campbell and colleagues identified a particular component produced by S. avermitilis called Avermectin B1a which had a broad efficiency against roundworm infections in a wide range of domesticated animal species, including cattle, sheep, dogs and chickens. Following this the team developed a modified form of Avermectin B1a known as Ivermectin, which was entered into clinical trials following positive tests in animal models of parasitic infection, and has since gone on to become a key treatment for parasitic infections – particularly the nematode worm infections that cause River Blindness and  Lymphatic Filariasis (the extreme manifestation of which is known as elephantitis) – and is on the World Health Organization’s list of Essential Medicines.

Image: NoberPrize.org

Image: NobelPrize.org

Ivermectin, and other members of the Avermectin family of therapies, are also widely used in veterinary practice, and their development and use is a good example of the One Health principle in action. You can learn more about the discovery of the Avermectins and Artemisinins in the advanced material Avermectin and Artemisinin – Revolutionary Therapies against Parasitic Diseases produced by the Nobel Assembly.

In 2011 we took a look at Professor Youyou Tu’s research that led to the development of Artemisinin therapy for malaria, and the key role played by mouse models of malaria infection,  in a post entitled “George is OK: Thank the men who stare down microscopes!”

While the news reports don’t state which drugs Cloony took to beat malaria, It is most likely that he was treated with artemisinin-based combination therapies (ACTs), which became available in the late 1990s and are now in widespread use.  If that is the case, he has benefited from mouse studies done in China the late 1960s and early 1970s when over 100 traditional herbal remedies were screened in a rodent model of malaria for anti-malarial activity (1). Eventually “Project 523” scored a hit when Professor Tu Youyou identified an extract of the plant qinghao, scientific name Artemisia annua, which had good anti-malarial activity, leading to the development of the artemisinin-based anti-malarials which have become the first-line treatment for malaria in the past decade.

We congratulate this years Nobel laureates in Physiology or Medicine, their research has improved the lives of hundreds of millions of people across the world over the past 3 decades, and will continue to do so. We hope that their success continues to inspire scientists around the world to rise to current and future public health challenges!

Speaking of Research

Truvada prevents HIV infection in high-risk individuals! A clinical success built on animal research

In the past two weeks we’ve learned of a major advance in ongoing efforts to halt the spread of  HIV, two separate clinical studies have reported that a daily regimen of a pill called Truvada as a pre-exposure prophylaxis (PrEP) is highly effective in preventing infection in high risk groups. This success is a result not just of the dedication of the clinicians who conducted these trials, but also of a series of pivotal studies conducted in non-human primates more than a decade ago that laid the scientific foundations for them.

In the first study of more than 600 high-risk individuals conducted at Kaiser Permanente in San Francisco, which was published in the journal Clinical Infectious Diseases, researchers found that Truvada – a combination of the anti-viral drugs tenofovir and emtricitabine – was 100% effective in preventing infection.  In the 2nd  study, called the PROUD study and published online this week in the Lancet, of more than 500 high-risk men undertaken in 13 sexual health clinics in England Truvada reduced infections by 86%.

Truvada prevents HIV transmission in high-risk individuals. Image: AFP / Kerry Sheridan

Truvada prevents HIV transmission in high-risk individuals. Image: AFP / Kerry Sheridan

These results have been greeted with enthusiasm in media reports, with headlines such as “Aids vanquished: A costly new pill promises to prevent HIV infection” , “A pill designed to prevent HIV is working even better than people thought” and  “Truvada Protected 100 Percent Of Study Participants From HIV: This is exciting!”. It’s worth noting that these are not the only trials to show the potential for Truvada to block HIV infection, earlier trials in Kenya, Uganda and Botswana also showed that it could substantially reduce infection rates, including in heterosexual couples where one partner was HIV positive and the other was not. There has been some concern that those taking Truvada would be less likely to take other safe sex measures – such as using condoms – but the results of the PROUD study showed no difference in acquisition of other sexually transmitted infections between those who started Truvada treatment immediately and those who delayed for 1 year, suggesting that they did not engage in riskier behavior as a consequence of taking Truvada.

Thanks to a multi-pronged approach to preventing HIV infection, combining barrier methods such as condoms,  Highly Active Antiretroviral Therapy (HAART) to lower viral load in infected individuals, and the use of antiviral medications to prevent mother-to-child transmission, the spread of HIV infection has slowed dramatically in many regions of the world, and pre-exposure prophylaxis with Truvada certainly has the potential to help reduce it further.

As we applaud the researchers who conducted these first real-world evaluations of Tenofovir in high-risk populations, it is also a good opportunity to remember the researchers whose work led us to this point. One of those pioneers is Dr. Koen Van Rompay, a virologist at the University of California at Davis who played a key role in the early development of Tenofovir and  its evaluation in pre- and post- exposure phophylaxis in macaque models of HIV infection. In 2009 Dr Van Rompay wrote an article for Speaking of Research explaining how important animal research was to the early development of such HIV prophylaxis regimes, and how important it continues to be as scientists develop ever better treatments, which we share again today:

Contributions of nonhuman primate studies to the use of HIV drugs to prevent infection – Koen van Rompay

Since the early days of the HIV pandemic, as soon as it was clear that an effective HIV vaccine would still be years away, there has been considerable interest in using anti-HIV drugs to reduce the risk of infection following exposure to HIV (so-called prophylaxis). Animal models of HIV infection, especially the rhesus macaque, have played a major role in developing and testing these treatments.

The development of HIV drugs to treat HIV-infected persons has shown that many compounds that are effective in vitro (i.e., in tissue culture assays) fail to hold their promise when tested in humans, because of unfavorable pharmacokinetics, toxicity or insufficient antiviral efficacy. The same principles apply to the development of drugs to prevent HIV infection. The outcome of drug administration is determined by many complex interactions in vivo between the virus, the antiviral drug(s) and the host; with current knowledge, these interactions cannot be mimicked and predicted sufficiently by in vitro studies or computer models.

Testing different compounds in human clinical trials is logistically difficult, time-consuming and expensive, so only a very limited number of candidates can be explored in a given time. Fortunately, the development of antiviral strategies can be accelerated by efficient and predictive animal models capable of screening and selecting the most promising compounds. No animal model is perfect and each model has its limitations, but the simian immunodeficiency virus (SIV) of macaques is currently considered the best animal model for HIV infection because of the many similarities of the host, the virus and the disease. Non-human primates are phylogenetically the closest to humans, and have similar immunology and physiology (including drug metabolism, placenta formation, fetal and infant development). In addition, SIV, a virus closely related to HIV-1, can infect macaques and causes a disease that resembles HIV infection and AIDS in humans, and the same markers are used to monitor the disease course. For these reasons, SIV infection of macaques has become an important animal model to test antiviral drugs to prevent or treat infection.

Studies in rhesus macaques first indicated that Tenofovir could block HIV infection. Photo: Understanding Animal Research

Studies in rhesus macaques first indicated that Tenofovir could block HIV infection. Photo: Understanding Animal Research

Different nonhuman primate models have been developed based on the selection of the macaque species, the particular SIV strain and the inoculation route (e.g. IV injection, vaginal exposure) used (reviewed in (33)). These models have been improved and refined during the past two decades. For example, SIV-HIV chimeric viruses have been engineered to contain portions of HIV-1, such as the enzyme reverse transcriptase (“RT-SHIV”) that the virus requires in order to multiply or the envelope protein (“env-SHIV”) that the virus needs if it is to escape from a cell and infect other cells, to allow these models to also test drugs that are specific for HIV-1 reverse transcriptase or envelope (28, 35).

Many studies in non-human primates have investigated whether the administration of anti-HIV drugs prior to or just after exposure to virus can prevent infection. The earliest studies indicated that drugs such as the reverse transcriptase inhibitor zidovudine (AZT), the first approved drug treatment for HIV, were not very effective in preventing infection, but a likely reason for this was the combination of a high-dose viral inoculums used, the direct intravenous route of virus inoculation, and the relative weak potency of drugs at that time (2, 4, 13, 19, 20, 36). The proof-of-concept that HIV drugs can prevent infection was demonstrated in 1992 when a 6-weeks zidovudine regimen, started 2 hours before an intravenous low-dose virus inoculation that more accurately represented HIV infection in humans, protected infant macaques against infection (29). These results were predictive of a subsequent clinical trial (Pediatric AIDS Clinical Trials Group Protocol 076), which demonstrated that zidovudine administration to HIV-infected pregnant women beginning at 14 to 34 weeks of gestation, and continuing to their newborns during the first 6 weeks of life reduced the rate of viral transmission by two-thirds (10).

Since then, a growing number of studies have been performed in macaques to identify more effective and simpler prophylactic drug regimens. These studies generally used lower virus doses, sometimes combined with a mucosal route of virus inoculation that mimics vaginal or anal exposure responsible for the majority of human HIV infections. These studies demonstrated that administration of some newer anti-HIV drugs, including the reverse transcriptase inhibitors adefovir (PMEA), tenofovir (PMPA), and emtricitabine (FTC) that prevent the virus from multiplying in the infected cell, and the CCR5 inhibitor CMPD167 that stops the virus from binding the CCR5 receptor on the cell surface and entering a cell in the first place, starting prior to, or at the time of virus inoculation, was able to prevent infection, though with varying success rates (3, 4, 16, 24, 25, 31, 34, 35). Only very few compounds such as the reverse transcriptase inhibitors tenofovir, BEA-005 and GW420867, and the CCR5 inhibitor CMPD167, were able to reduce infection rates when treatment was started after virus inoculation. For those drugs that were successful in post-exposure prophylaxis studies, a combination of the timing and duration of drug administration was found to determine the success rate, because a delay in the start, a shorter duration, or interruption of the treatment regimen all reduced the prophylactic efficacy (5, 11, 21, 22, 26, 27, 31) , information that has guided the design of subsequent clinical trials.

While some of the compounds such as GW420867 that showed prophylactic efficacy in the macaque model are no longer in clinical development (e.g., due to toxicity or pharmacokinetic problems discovered later in pre-clinical testing), the very promising results achieved with tenofovir have sparked further studies aimed at simplifying the prophylactic regimen. Several studies in infant and adult macaques have demonstrated that short or intermittent regimens of tenofovir (with or without coadministration of emtricitabine) consisting of one dose before and one dose after each virus inoculation were highly effective in reducing SIV infection rates (15, 30, 32).

The demonstration at the beginning of the 1990’s that anti-HIV drugs can prevent infection in macaques has provided the rationale to administer these compounds to humans to reduce the likelihood of infection in several clinical settings. Antiviral drugs are now recommended, usually as a combination of several drugs, to reduce the risk of HIV infection after occupational exposure (e.g., needle-stick accidents of health care workers) and non-occupational exposure (e.g. sex or injection-drug use) (6, 7). As mentioned previously, drug regimens containing zidovudine and more recently also more potent drugs such as nevirapine have proven to be highly effective in reducing the rate of mother-to-infant transmission of HIV, including in developing countries (10, 14, 17), and save many thousands of lives every year . Because the short nevirapine regimen that is given to pregnant HIV-infected women at the onset of labor frequently induces drug resistance mutations in the mother that may compromise future treatment (12), tenofovir’s high prophylactic success in the infant macaque model has sparked clinical trials in which a short tenofovir-containing regimen was added to existing perinatal drug regimens to reduce the occurrence of resistance mutations and/or further lower the transmission rate (8, 9, 18, 30, 32).

Scanning electron micrograph of HIV-1, colored green, budding from a cultured lymphocyte. Photo: C. Goldsmith Content Providers: CDC/ C. Goldsmith, P. Feorino, E. L. Palmer, W. R. McManus

Scanning electron micrograph of HIV-1, colored green, budding from a cultured lymphocyte. Photo: C. Goldsmith Content Providers: CDC/ C. Goldsmith, P. Feorino, E. L. Palmer, W. R. McManus

Because an efficacious HIV vaccine has so far not been identified, the concept of using pre-exposure prophylaxis also as a possible HIV prevention strategy in adults has gained rapid momentum in recent years. The promising prophylactic data of tenofovir (with or without emtricitabine) in the macaque model (23, 32, 35, 37) combined with the favorable pharmacokinetics, safety profile, drug resistance pattern and therapeutic efficacy of these drugs in HIV-infected people, have pushed these compounds into front-runner position in ongoing clinical trials that investigate whether uninfected adults who engage in high-risk behavior will have a lower infection rate by taking a once daily tablet of tenofovir or tenofovir plus emtricitabine. The results of these ongoing trials are highly anticipated. An overview of the design, status and challenges of these trials which are currently underway at several international sites and target different high-risk populations can be found on the website of the AIDS Vaccine Advicacy Coalition (1, 23).

In conclusion, nonhuman primate models of HIV infection have played an important role in guiding the development of pre- and post-exposure prophylaxis strategies. Ongoing comparison of results obtained in these models with those observed in human studies will allow further validation and refinement of these animal models so they can continue to provide a solid foundation to advance our scientific knowledge and to guide clinical trials.

Koen van Rompay DVM Ph.D. is a research virologist at the California National Primate Research Center at UC Davis.

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Israel provides animal research statistics for 2014

The 2014 statistics from the Israeli National Council for Animal Experimentation show a 13 percent increase in animals used, reports Haaretz, an Israeli newspaper.

The 340,330 animals used in experimentation in 2014 represent the highest animal use since 2007, the peak of animal experimentation in Israel. Rodents comprised the majority (84 percent) of the animals used for experiments, birds and fish came next with around 7% each, while larger mammals accounted for only 1.3 percent of the total. The number of mice used, 236,000, represents a 12 percent increase over the 2013 amount.

Animals used in research in Israel 2010-14

For the second year in a row, no dogs or cats were used as experimental subjects. More monkeys were used for experimentation than in previous years; however, the National Council for Animal Experimentation report notes that Israel, with a rehabilitation rate of 89 percent, ranks among the countries with the highest reintegration rates for monkeys.

Dogs cats monkeys used in Israel 2010-2014

Seven percent of the animals were fish, which represents a three-fold increase over the previous year. The report by the National Council for Animal Experimentation attributes this increase to a concerted effort to use the lowest animal on the “developmental scale” that is scientifically appropriate.

On the five point pain scale, 12 percent of experimental animals were exposed to the highest amount of pain and 19 percent were ranked in the lowest pain category. Strict supervision of the animals by veterinarians and unannounced laboratory inspections prevent unnecessary pain for the animals, The Jerusalem Post reports.

Medical and scientific research were the main uses for the animals, accounting for 46 and 45 percent, respectively. Testing new products and materials used eight percent of the animals, and one percent was used for teaching.

Transparent reports of animal use contribute to public education about animal research. Speaking of Research continues to report on these statistical reports as they come out, most recently the 2014 statistics for the United States and Ireland and the 2012 Canadian report.

Alyssa Ward

USDA publishes 2014 Animal Research Statistics

Congratulations to the USDA/APHIS for getting ahead of the curve and making the US the first country to publish its 2014 animal research statistics. Overall, the number of animals (covered by the Animal Welfare Act) used in research fell 6.4% from 891,161 (2013) to 834,453 (2014).

These statistics do not include all animals as most mice, rats, and fish are not covered by the Animal Welfare Act – though they are still covered by other regulations that protect animal welfare. We also have not included the 166,274 animals which were kept in research facilities in 2014 but were not involved in any research studies.

Types of Animals used in research and testing 2014Statistics from previous years show that most of the “All other animals” species are rodents (but not mice or rats). 53% of research is on guinea pigs, hamsters and rabbits, while 10% is on dogs or cats and 7% on non-human primates. In the UK, where mice, rats, fish and birds are counted in the annual statistics, over 97% of research is on rodents, birds and fish. Across the EU, which measures animal use slightly differently, 93% of research is on species not counted under the Animal Welfare Act. We would expect similar patterns to be true in the US – although there are no statistics to confirm this.

Changes in number of animals used in research from 2013 to 2014 - Click to Enlarge

Changes in number of animals used in research from 2013 to 2014 – Click to Enlarge

If we look at the changes between the 2013 and 2014 statistics we can see a drop in the number of animals of most species , with only the “all other animals” category showing a rise. This is the second year in which the number of many species has fallen. For example, the number of rabbits used in 2014 fell 11.4% from 2013, following a 9.2% fall from 2012.

Most notably the number of non-human primates has fallen by 9.9%, the number of dogs fell 12.4% and the number of cats fell by 13%. This has shown these species taking up a smaller proportion of the research animals used, as can be seen below:

Trend in number of animals used in research 1973 - 2014 - Click to Enlarge

Trend in number of animals used in research 1973 – 2014 – Click to Enlarge

Clearly there has been a downward trend in the number of animals used since the early 1990s with a 61% drop in numbers between 1992 and 2014. It is also likely that, similar to the UK, a move towards using more genetically altered mice and fish has reduced the numbers of other AWA-covered animals used.

Rises and falls in the number of animals used reflects many factors including the level of biomedical activity in a country, trending areas of research, changes to legislations at home and abroad, outsourcing research to and from other countries, and new technologies (which may either replace animal studies or create reasons for new animal experiments).

It is important to note that the number of animals cannot be tallied across years to get an accurate measure of total number of animals. This is because animals in longitudinal studies are counted each year. Thus, if the same 10 animals are in a research facility for 10 years, they would appear in the stats of each year – adding these numbers would incorrectly create the illusion of 100 animals being used.

Speaking of Research welcomes the open publication of these animal research statistics as offering the public a clear idea of what animal research goes on in their country.

Clinical trial success for Cystic Fibrosis gene therapy: built on animal research

This morning the Cystic Fibrosis Gene Therapy Consortium (GTC) announced the results of clinical trial in 140 patients with cystic fibrosis, which demonstrate the potential for gene therapy to slow – and potentially halt – the decline of lung function in people with the disorder. It is a success that is built on 25 years of research, in which studies in animals have played a crucial role.

Cystic fibrosis is one of the most commonly inherited diseases, affecting about one in every four thousand children born in the USA, and is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR gene produces a channel that allows the transport of chloride ions across membranes in the body, and the many mutations identified in cystic fibrosis sufferers either reduce the activity of the channel or eliminate it entirely. This defect in chloride ion transport leads to defects in several major organs including the lungs, digestive system, pancreas, and liver. While the severity of the disease and the number of organs affected varies considerably, cystic fibrosis patients often ultimately require lung transplant s, and too many still die early in their 20’s and 30’s as the disease progresses.

In a paper published in Lancet Respiratory Medicine today (1), the GTG members led by Professor Eric Alton of Imperial College London compared monthly delivery to the airway of a non-viral plasmid vector containing the CFTR gene in the liposome complex pGM160/GL67A using a nebuliser with a placebo group who received saline solution via the nebuliser. They reported stabilisation of lung function in the pGM169/GL67A group compared with a decline in the placebo group after a year. This is the first time that gene therapy has been shown to safely stabilise the disease, and while the difference between the treated and control group was modest, and the therapy is not yet ready to go into clinical use, it provides a sound bases for further development and improvement.


The Chief Executive of the Cystic Fibrosis Trust, which is one of the main funders of the GTC, has welcomed the results, saying:

Further clinical studies are needed before we can say that gene therapy is a viable clinical treatment. But this is an encouraging development which demonstrates proof of concept.

“We continue to support the GTC’s ground-breaking work as well as research in other areas of transformational activity as part of our mission to fight for a life unlimited by cystic fibrosis.”

So how did animal research pave the way for this trial?

Following the identification of the CFTR gene in 1989 scientists sought to create animal models of cystic fibrosis with which to study the disease, and since the early 1990’s more than a dozen mouse models of cystic fibrosis have been created. In some of these the CFTR gene has been “knocked out”, in other words completely removed, but in others the mutations found in human cystic fibrosis that result in a defective channel have been introduced. These mouse models show many of the defects seen in human cystic fibrosis patients and over the past few years have yielded important new information about cystic fibrosis, and in 1993 Professor Alton and colleagues demonstrated that it is possible to deliver a working copy of the CFTR gene using liposomes to the lungs of CFTR knockout mice and correct some of the deficiencies observed.

To get a working copy of the CFTR gene to the lungs of cystic fibrosis patients Professor Alton and colleagues needed three things:

• A DNA vector containing the working CFTR gene that is safe and  can express sufficient amounts of the CFTR channel protein in the lungs to correct the disease

• A lipid-like carrier that can form a fatty sphere around the DNA vector to so that it can cross the lipid membrane of cells in the lung, as “naked” DNA will not do this efficiently.

• A nebuliser device that produces an aerosol of the gene transfer agent so that it can be inhaled into the lungs of the patient.

Several early attempts to use gene therapy using viral vectors to deliver the working copy of the CFTR gene to patients failed because the immune response rapidly neutralised the adenoviral vector (see this post for more information on challenges using adenoviral vectors), and while attempts to use non-viral vectors were more promising, it was found that they caused a mild inflammation in most patients, which would make then unsuitable for long term use. As reported in a paper published in 2008 the GTC members developed and assessed in mice a series of non-viral DNA vectors, repeatedly modifying them and testing their ability to both drive CFTR gene expression in the lungs and avoid inducing inflammation. They finally hit on a vector – named pGM169 – which fulfilled both key criteria.

Earlier the consortium had undertaken a study to determine which carrier molecule to use in their non-viral gene transfer agent (GTA). To do this they assessed 3 GTA’s, each consisting of a lipid like molecule that could form a sphere around the non-viral DNA vector; either the 25 kDa-branched polyethyleneimine (PEI), the cationic liposome GL67A, or as a compacted DNA nanoparticle formulated with polyethylene glycol-substituted lysine 30-mer. Because there are significant differences in airway physiology between mouse and human they carried out this study in sheep, whose lung physiology more closely matches that of humans. The study identified the cationic liposome GL67A as the most promising candidate, resulting in robust expression of the CFTR transgene in the sheep lungs.

Studies in sheep play a key role in the development of gene therapy for cystic fibrosis

Studies in sheep play a key role in the development of gene therapy for cystic fibrosis

It now remained to bring the DNA vector and carrier together. In a 2013 publication the consortium reported that repeated aerosol doses of pGM169/GL67A to sheep over a 32 week period were safe and induced expression of the CFTR transgene in the sheep lungs, although the level of expression varied between individuals (this variation was also observed in human CF patients in the clinical trial reported today). A final study, this time in mice, assessed the suitability of the Trudell AeroEclipse II nebuliser as a device to create stable pGM169/GL67A aerosols, finding that it did so in a reproducible fashion. When aerosolized to the mouse lung, the new pGM169/GL67A formulation was capable of directing persistent CFTR transgene expression for at least 2 months, with minimal inflammation. These studies provided the evidence to support the gene delivery system and dosage strategy used in the clinical trial reported today.

The trial results announced today are an important accomplishment, but they mark a beginning rather than the end for Cystic Fibrosis gene therapy. It will be necessary to improve the efficiency of the therapy before it can enter widespread clinical use. Animal research will certainly play an important part in this work, notably the observation that the efficiency of CFTR gene delivery using this strategy was varied between individuals in both sheep and humans indicates that sheep are a good model in which to assess changes to improve the consistency and effectiveness of the gene therapy.

If you would like to know more about this cystic fibrosis gene therapy clinical trial you can watch two videos recorded at a meeting for cystic fibrosis patients at ICL on the  Cystic Fibrosis Trust website.

Paul Browne

1) Alton E.W.F.W. et al. “Repeated nebulisation of non-viral CFTR gene therapy in patients with cystic fibrosis: a randomised, double-blind, placebo-controlled, phase 2b trial” Lancet Respiratory Medicine Published online July 3, 2015