Numbers and types of animals 

In some situations, mice and rats are not suitable and larger animals may need to be used. For example, ferrets, sheep and turkeys are important for producing seasonal flu vaccines as they are used to prepare vital reference materials. These materials support manufacturers to make new vaccines each winter to protect people from the ever-changing and often life-threatening flu virus. 

The use of non-human primates, such as Macaques and Tamarins, is only undertaken when there is no other valid alternative. Non-human primates are used to support some of our essential research into complex and deadly viruses such as HIV and Zika. 

Why have some animal numbers increased in 2017

In 2017 the total number of animals used decreased by more than 5% from 2016. This included a reduction of over 65% in the number of rats used and over 80% decrease in the number of guinea pigs used.

We are committed to reducing, replacing and refining animal use. However, depending on the research undertaken numbers can vary year on year, and in 2017 we saw an increase in the number of animals used for some species. For example:

• In 2017 we were involved in a research project to develop new flu vaccines that could potentially offer broader and longer-lasting protection for patients. Ferrets are an important model for flu research as they are susceptible to infection with human influenza viruses and have a similar respiratory tract to humans. In this study, ferrets were used to show the effectiveness of a new type of ‘universal’ flu vaccine currently under development.  

• Biosimilar medicines or ‘biosimilars’ are now being developed for monoclonal antibodies widely used to treat health conditions such as cancer, inflammation and infectious diseases. Biosimilars must be highly similar to the original licensed product and meet regulatory requirements in terms of their safety, quality and efficacy. A NIBSC study used Alpacas to produce small-size antibodies known as nanobodies against the monoclonal antibody, Rituximab. Because these nanobodies recognise different parts of the Rituximab product, they can be used to support the comparison of new ‘biosimilar’ Rituximab products coming to market with the original approved version. Unlike conventional monoclonal antibodies, nanobodies can only be produced in camelid species like alpacas. The alpacas used in these studies are reported to the Home Office on completion of the study, which is when the animals are re-homed.

• In 2015-2016 an outbreak of Zika virus caused the World Health Organization (WHO) to declare a public health emergency following evidence this outbreak had serious implications for pregnant women, with infection being linked to birth defects such as abnormally small heads (microcephaly). The WHO called on researchers to prioritise research into the disease. At NIBSC, we initiated new work involving non-human primates to support the production of standards and reference materials that could be used by manufacturers to speed up the development of vaccines against the disease. Non-human primates are used only when other species are considered not to be suitable. Following extensive investigation non-human primate models were selected for this study due to the close similarities to humans in brain structure and function and the female reproductive tract. Scientists observed differences in the outcome of protection studies between mouse and non-human primate models, which could be critical for selecting suitable models for future Zika vaccine development and evaluation.

Replacing, reducing and refining animal use (the 3Rs principles)

Our scientists develop non-animal tests to check the quality and safety of biological medicines and provide evidence and advice to encourage their use by organisations worldwide. For example, we’ve helped introduce alternative methods for testing polio vaccines, greatly reducing the use of non-human primates.

Find out more about our work to replace, reduce and refine animal use.