Vaccinating domestic animals, including pet dogs and cats, against Covid-19 may be necessary in the future, scientists have warned.
Coronavirus is capable of infecting a wide range of species, meaning there is a significant risk of transmission to humans without vaccination.
‘We need to be prepared’
Experts from the University of East Anglia (UEA), the Earlham Institute in Norwich and the University of Minnesota, have said that vaccination of domesticated animals might be necessary to curb the spread of coronavirus.
In an editorial for the journal Virulence, they wrote that the continued evolution of the virus in animals, followed by transmission to humans, “poses a significant long-term risk to public health”.
Last year, Denmark’s government was forced to cull millions of mink after it emerged that hundreds of Covid-19 cases in the country were linked with coronavirus variants associated with farmed mink.
Cock van Oosterhout, professor of evolutionary genetics at UEA and one of the editorial’s authors, said that dogs and cats are capable of contracting Covid-19, but as yet there are no known cases in which there has been transmission back to humans.
However, he added that it would be beneficial to develop a vaccine for pets as a precautionary measure.
He said: “It makes sense to develop vaccines for pets, for domestic animals, just as a precaution to reduce this risk.
“What we need to be as a human society, we really need to be prepared for any eventuality when it comes to Covid.
“I think the best way to do this is indeed to consider development of vaccines for animals as well.
“Interestingly the Russians have already started to develop a vaccine for pets, which there’s very little information about.”
Preventing animal-specific strains
Kevin Tyler, editor-in-chief of Virulence, said that while cats are asymptomatic, they can be infected by Covid-19 and pass this on to humans.
He explained: “The risk is that, as long as there are these reservoirs, that it starts to pass, as it did in the mink, from animal to animal, and then starts to evolve animal-specific strains, but then they spill back into the human population and you end up essentially with a new virus which is related, which causes the whole thing all over again.”
Prof van Oosterhout and Prof Tyler wrote the editorial along with director of the Earlham Institute Neil Hall and Hinh Ly of the University of Minnesota.
In their editorial, the scientists wrote: “Continued virus evolution in reservoir animal hosts, followed by spillback events into susceptible human hosts, poses a significant long-term risk to public health.
“SARS-CoV-2 can infect a wide range of host species, including cats, dogs, mink and other wild and domesticated species and, hence, the vaccination of domesticated animals might be required to halt further virus evolution and spillback events.
“Whilst the vaccination campaigns against Sars-CoV-2/Covid-19 are being rolled out worldwide, new virus variants are likely to continue to evolve that have the potential to sweep through the human population.”
They warned that more transmissible virus strains, such as the UK variant, require more people to be vaccinated to keep coronavirus under control.
The scientists have called on governments to consider the continued use of strict control measures, such as masks and social distancing, as the only way to reduce the evolution and spread of new Covid-19 variants.