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Developing a new animal free tool to detect COVID-19

Professor Lorna Harries and PhD student Merlin Davies at the University of Exeter are conducting a study to validate a novel, animal free test to measure the number of active (working) COVID-19 viruses to predict clinical outcomes and quickly identify those at most risk.

‘This study will actually be one of the first to demonstrate that human-relevant immune system research can be done without the use of animal-derived experiments and reagents. This is particularly exciting when I see all of the great data we are getting!’ – Merlin Davies

The spread of viruses

The virus that causes COVID-19

A virus is an infectious microbe consisting of genetic material (for example DNA) surrounded by a protein coat. Viruses depend on the person (host) they infect for their survival. They insert their genetic material into a host’s cells, hijacking their internal machinery to make more virus particles. When a virus is active (’alive’), it makes copies of itself then usually destroys the host cells to set these newly formed virus particles free. These can then infect other cells and spread outside the body into other hosts. The number of free virus particles within the host is known as the ‘viral load’, and if a person has a high viral load, they are more likely to infect other people.

Testing viral load in COVID-19

COVID-19 is a disease caused by a virus named SARS-CoV-2 and was discovered in December 2019. It is very contagious and has quickly spread around the world. Currently, routine testing for COVID-19 only measures viral fragments which are parts of the virus which have been shed. These can be infectious or non-infectious, so people can test positive for months even though they may not be an infection risk to others. This can be a problem for many people wanting to return to institutions, such as rehabilitation or work, and also for those awaiting bone marrow transplants who need a negative test before they can proceed. Measuring a person’s viral load which measures an active virus, could be more useful in reflecting how infectious a person is.

Developing an animal free COVID-19 test

Merlin Davies, PhD student

Merlin Davies is undertaking a PhD, working alongside Professor Lorna Harries, at the University of Exeter’s Animal Free Research Centre of Excellence (ARC 2.0). The research team have developed a new test which involves measuring the amount of a viral genetic material. They are using leftover nasopharyngeal samples (mucus samples taken from the top of the throat) from patients and healthcare workers who tested positive for COVID-19. This viral genetic material directly reflects active COVID-19 viral load (the number of viruses that are working or ‘active’ within the body).

Merlin is validating the test to show it works effectively and can be used routinely in the NHS. He’s measuring active viral load in hospital patients to assess if it accurately predicts clinical outcomes and also testing if healthcare workers have a higher viral load than the general population.

The current tests for the virus that causes COVID-19 include ingredients derived from animals, such as bovine serum albumin, a protein purified/extracted from the blood of cattle and a by-product of slaughter. Merlin and his team have modified the test, so it is free-from animal ingredients.

Professor Lorna Harries



Impact of the research: benefits for humans and animals

As well as indicating if a person is infectious, viral load information, when combined with other health data such as age, signs and symptoms of infection and drug treatment, could help predict who is most at risk of developing COVID-19 and becoming severely unwell. This would be useful for doctors when planning treatment, for example, those that may require hospitalisation, oxygen and ventilation. It would also help prevent hospital overload so capacity can be planned for those that need it and people at low risk could be released sooner. Measuring viral load could also be used to monitor the effects of new and existing treatments on the virus. This would enable frontline healthcare workers to return to work safely in a shorter timeframe and allow more accurate testing of individuals returning to care homes from hospital. As the test is free from animal ingredients, it paves the way for eliminating animal derived products in clinical testing, ultimately saving the lives of thousands or more animals.


The Animal Replacement Centre (ARC 2.0) at the University of Exeter is a win-win-win for humans, animals and research. It’s establishing the building blocks to grow expertise and understanding of animal-free techniques.

But we urgently need your help. With the economic downturn and reduced funding to medical research, we are counting on your generous, ongoing support to fund ARC 2.0’s innovative, multi-year projects, which could be life-changing.