The New Zealand Anti-Vivisection Society (NZAVS) recently published an article on the use of animals in research to combat Covid-19.
In the article there are a number of claims that research using animals should not be used in Covid-19 research and treatment development. However, the implications for global healthcare if research with animals is not permitted includes delaying progress towards a treatment for Covid-19 while new animal-free technologies and practices are developed and validated resulting in more deaths.
In addition, it would put human volunteers in clinical trials at significantly more risk or adverse side-effects without preclinical animal studies to demonstrate their safety.
Here we will explore these claims to better understand why animals are being used in the fight against Covid-19 across the globe.
No matter where we stand on the use of animals in research, we are all anxious to find a treatment for Covid-19 as quickly as possible. Hence why researchers globally are seeking to use the most effective research methods available, which can mean using animals provided the scientific and ethical aspects of such research are robustly assessed in each case.
The pressure from the pandemic will not excuse unethical research, animals will only be used where the potential insights gained are essential for combating Covid-19.
Animal research 'is unreliable'
‘With the use of animals to try and model the human response to drugs and disease failing over 95% of the time we can't ignore the elephant in the room...The animal model would just slow vaccine development down without producing useful data.’ (NZAVS)
This is their first claim to support the abandonment of animals in Covid-19 research and drug development. Put concisely, the use of animals is unnecessary and slows down progress towards treatments.
Later in a section written by NZAVS’s scientific advisor Andrea Menache, this statistic is reinforced with the claim that according to the US FDA nine out of ten successful animal tests fail in human trials.
NZAVS does not reference the source of the 95% figure, however it likely refers to percentage of drugs which pass animal tests that fail during human clinical trials stages (94% between 2007-2011).
There is no real dispute about this figure from the biomedical community, scientific progress is built on failure in all types of research, animal-free studies included.
The inaccuracies and misunderstanding surrounding these statistics have been explained in detail in an article by Prof Robin Lovell-Badge of the MRC National Institute for Medical Research, London.
He outlined that a high failure rate does not mean animal research is unreliable, and seeing it as such represents a misunderstanding of preclinical research, which isn’t to learn whether a drug will work in humans but whether it has potential therapeutic value and if it is safe enough for Phase I clinical trials in humans.
Consider that of all the drugs which pass Phase I clinical trials in humans, 86% will fail in later trials. Yet, we do not hear activists suggesting that humans are an entirely inappropriate model for drug development.
Animal studies continue to be a useful tool in drug development, for example monkeys were used to successfully predict the effectiveness of two new Ebola vaccines recently, and using monkeys is an extremely good way of predicting if a drug will be toxic at the intended dose, again demonstrating the importance of animal models before starting human clinical trials.
Skipping animal testing in therapeutic development
‘One study being conducted in the US has skipped some animal trials entirely as a way of fast-tracking the discovery of a vaccine.’ (NZAVS)
NZAVS supports their initial claim by citing a new experimental Covid-19 vaccine developed by the biotechnology company Moderna Therapeutics, which bypassed animal testing and went straight to human trials. However, virologists at the National Institute of Allergy and Infectious Diseases actually did test the vaccine on mice on the same day that human trials began.
In fact, Moderna were not entirely skipping animal testing as previous related study using mice provided the confidence to go to human trials. Their experimental vaccine is based on mRNA, a molecule which carries information to make proteins, whereas typically vaccines contain the dead or weakened virus. Once in the body the specially designed mRNA constructs proteins which kill the virus. However, before it can attack the virus, first the mRNA must be able to avoid the cells natural defense responses, an advancement which was achieved at the University of Pennsylvania with the help of successful mouse studies. Furthermore, animal studies have contributed throughout the development process of this mRNA technology, including studies in monkeys, providing essential insight into its potential as a therapeutic.
Several of these animal studies were conducted by Moderna itself, so the example used by NZAVS is misleading.
‘Testing vaccines and medicines without taking the time to fully understand safety risks [through animal studies] could bring unwarranted setbacks during the current pandemic, and into the future.’ – Writes Prof Shibo Jiang, Fudan University, who has been working on coronavirus vaccines and treatments since 2003, in Nature.
There is no known successful vaccine that has so far avoided using animals at some stage in its development and if the Moderna vaccine is successful it will again be thanks in some small part to the use of animals in research.
A lack of suitable animal models to study Covid-19
Mr Menache writes that due to the intensity of the current pandemic scientists have not had time to develop an animal model to study Covid-19, but this is simply not true.
Here are examples of studies that have used animals as models to study Covid-19:
Researchers from the University of Hong Kong demonstrate hamster models of Covid-19 “closely resemble the manifestations of upper and lower respiratory tract [Covid-19] infection in humans”
A collaborative study between institutes in South Korea and the US found ferrets can model respiratory transmission of Covid-19 among other aspects of the infection.
One study in monkeys have successfully mimicked human symptoms seen in mild cases of Covid-19 infections in humans. Another study found monkeys were resistant to reinfection four weeks after recovering from Covid-19, provided good news that humans will likely have immunity post-infection.
More examples of studies that have used animals as models to study Covid-19 can been found here.
Stop using animals and invest in alternatives instead
‘Rather than experimenting with ferrets, monkeys or mice, it would be more intelligent – and far more scientific – to invest in high-performance technologies of the 21st century.’ (NZAVS)
Finally, NZAVS’s article ends claiming it would be better to invest in animal-free technologies to tackle Covid-19 in place of animal research. Unfortunately, these technologies either do not exist yet, or are being used already, as EU law always requires the use of alternatives to animal models when these are available.
Investment in better tools (animal-free or not) to combat Covid-19 should certainly be a priority, however our current tools should not be put aside while we wait for new ones to appear.
Animal models are an essential technology in studies to guarantee the safety and efficacy of new drugs and treatments and will continue to be an important contributor in the fight against Covid-19.