Cats and dogs could have to be vaccinated against Covid-19 in future, a group of scientists has said.
They said that transmission from animals to humans poses a ‘significant long-term risk’ because domesticated species can become infected and the virus continuously evolves in them as well.
‘It is not unthinkable that vaccination of some domesticated animal species might … be necessary to curb the spread of the infection,’ the experts from the University of East Anglia, the Earlham Institute in Norwich and the University of Minnesota wrote in an editorial for the journal Virulence.
In Denmark last year, hundreds of Covid-19 cases were caused by variants associated with farmed mink, leading to millions of the animals being culled.
One of the authors, Cock van Oosterhout, professor of evolutionary genetics at UEA, said: ‘It makes sense to develop vaccines for pets … We really need to be prepared for any eventuality.’
He pointed out that Russia has started to develop a vaccine for pets.
Kevin Tyler, editor-in-chief of Virulence, said: ‘Cats are asymptomatic but they are infected by it and they can infect humans with it.
‘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.’
He said that while mink were culled in Denmark, ‘if you were thinking about domestic animals, companion animals, then you might think about whether you could vaccinate to stop that from happening’.
He added: ‘It’s not an obvious risk yet.’
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 said that more transmissible virus strains, such as the UK variant, require more people to be vaccinated to keep coronavirus under control.
‘Vaccination against a viral pathogen with such high prevalence globally is without precedent and we, therefore, have found ourselves in uncharted waters,’ they wrote.
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.