We are now sixteen months on from the start of the COVID-19 pandemic and the largest vaccination programme in British history is underway in the UK. However, while the majority of media attention is focussed on vaccination of humans against the SARS-COV-2 virus, significant research and development work has also been underway to develop COVID vaccines for animals.

Governments are also now looking to the future and putting in place measures to prevent future pandemics, and a key part of the UK Government’s planning is the control of zoonotic diseases. In support of this plan, the UK announced last month at the G7 Summit in Cornwall that a new UK Animal Vaccine Manufacturing and Innovation Centre will be established in Surrey with the aim of speeding up vaccine development for livestock and to curb the spread of disease from animals to humans.

The case for vaccinating animals against COVID-19

Although the focus of the world’s attention has largely been on the human cost of the pandemic, since the start of the outbreak scientists have also been concerned about the impact of COVID-19 on animal populations and warn that spread of the virus in animals could have significant consequences for public health, economies and wildlife.

Public health: From a public health perspective, the most pressing reason for vaccinating animals against SARS-CoV-2 would be to prevent any spread of the virus from animals to humans. However, while there have been a small number of cases of animals infected by COVID-19 (including pet cats and dogs, captive tigers and gorillas and farmed mink), the US Centers for Disease Control and Prevention (CDC) have reported that there is no evidence that animals play a significant role in spreading SARS-CoV-2 to humans. However, concerns remain and the CDC has stated that further studies are needed to understand if and how different animals could be affected by the virus, and the role animals may play in the spread of SARS-CoV-2 to other animals and people.

Agriculture: There are also legitimate economic reasons for vaccinating animals against SARS-CoV-2. Spread of the virus in farmed animal populations has the potential to have devastating effects on economies. Mink are particularly susceptible to the virus and there have been high levels of infections and deaths at mink farms. Most notably, the mink outbreak in Denmark last year resulted in millions of mink being culled. As a result, the Danish mink industry has now been shut down until 2022 putting thousands of jobs at risk with significant impact on local communities.

Wildlife conservation: In addition to the public health and economic perspectives, there are also wildlife conservation arguments for vaccinating animals. Although the SARS-CoV-2 virus seems only to cause a mild respiratory illness in some species such as cats and dogs, other species are affected more seriously (such as mink). Scientists are particularly concerned about endangered animal species such as chimpanzee and gorillas as great apes are particularly susceptible to human respiratory diseases which have previously been fatal in those species.

Despite these arguments, opinion is still divided as to whether animals should receive a vaccine against COVID-19. In the UK, DEFRA has stated that at present it does not consider it necessary to vaccinate animals against SARS-CoV-2. However, other countries are taking a different approach, including Russia which has begun to vaccinate animals with its newly developed Carnivak-Cov vaccine. In the US, the USDA is accepting applications for licences for mink vaccines but has stated that it is not currently approving any applications for vaccines for cats and dogs “because data do not indicate such a vaccine would have value”. As it the case with many animal health vaccines and therapies, whether a particular product ever makes it to market will likely depend in part on an assessment of the cost benefit analysis. Unless there is a significant threat to human health or the animals themselves are valuable (e.g. rare zoo animals, lucrative livestock such as mink, or race horses and prize pets whose owners will spend whatever it takes to protect their animal) a product may not attract the attention and investment needed to bring it to market. This may present a challenge in low income countries in particular, especially given the well-publicised difficulties in the roll-out of human vaccines in those countries.

In any event, we anticipate that scientists and regulators will continue to monitor the effect that COVID-19 has on different species of animals and the corresponding human health cost and, particularly given the development work that has already been undertaken, will be swift to act and roll out new animal vaccines should this be necessary.

Current animal COVID vaccine candidates

In March 2021, Russia announced that it had registered its Carnivak-Cov vaccine for animals, claiming it to be the world’s first vaccine for animals against COVID-19. In May it began to roll out the vaccine at veterinary clinics in several regions with increasing vaccination requests coming from pet owners, breeders and owners of free range animals.

In the US, leading animal health company Zoetis has also developed a vaccine which has been authorised in the US for experimental use on a case by case basis. After the first case of a dog begin infected was reported in February 2020, Zoetis began developing a vaccine for cats and dogs. Since then has since shifted its development work to mink as outbreaks in Denmark and elsewhere lead to millions of mink being culled. Zoetis has also provided samples of its vaccine for experimental use in great apes at the San Diego Zoo and in July 2021 donated over 11,000 doses to nearly 70 zoos across the United States. According to Zoetis, the Oakland zoo has already used the doses to vaccinate tigers, black and grizzly bears, mountain lions.

While details of the Russian Carnivak-Cov vaccine have not been made public, the Zoetis vaccine is similar to the Novavax vaccine for humans which uses a modified form of the SARS-CoV-2 spike protein.

Looking beyond COVID-19

According to the UK’s Pirbright Institute, one of one of the UK’s leading virus diagnostics and surveillance centres, three in every four new human diseases originate in animals (as is believed to have happened with the SARS-COV-2 virus) and these diseases are emerging at an increasing rate.

In recognition of this, as part of a landmark global health declaration agreed by G7 leaders at the recent G7 meeting at Carbis Bay in Cornwall, the UK government has announced the establishment of a UK Animal Vaccine Manufacturing and Innovation Centre at the Pirbright Institute. The new institute will be funded by the Foreign Commonwealth and Development Office, the Biotechnology and Biological Sciences Research Council, and the Bill & Melinda Gates Foundation. The centre aims to accelerate the delivery of vaccines for livestock diseases and, recognising that early vaccine research can struggle to attract private investment, will focus on assessing new technologies and testing novel vaccines for emerging diseases.[1]

The Carbis Bay declaration also includes a commitment to champion a “One Health” approach to pandemic prevention, preparedness, detection and response. One health (or one medicine, as we have written about previously here) involves sharing knowledge and expertise between human health and animal health experts in order to improve treatment for both humans and animals.[2]

Conclusion

While the development of vaccines for animals is certainly not a new field, the COVID-19 pandemic has highlighted the role that animal health has to play in preventing future diseases. In the near term we expect the debate to continue about the necessity of COVID vaccines for animals (and the associated cost-benefit analysis) and will continue to monitor developments as the existing candidates are used more widely in a variety of species. In the long term we welcome the renewed focus on the need for investment in animal vaccines and the expansion of the UK’s capabilities in this area and hope that the lofty commitments made by the G7 are effective to prevent another pandemic as devastating as COVID-19.

——-
[1] https://www.pirbright.ac.uk/news/2021/06/new-animal-vaccine-manufacturing-and-innovation-centre-be-established-pirbright
[2] https://www.g7uk.org/wp-content/uploads/2021/06/G7-Carbis-Bay-Health-Declaration-PDF-389KB-4-Pages.pdf