According to a study from Chinese scientists, the SARS-CoV-2 variant first discovered in the UK, B.117, may have come from a dog. If this is confirmed, the dogs are at risk of destruction or need to be vaccinated separately.
Variant B.117 was first spotted in London and neighboring Ken County. Photo: AP Researchers in Shanghai have traced the original evolutionary trail of variant B.117, which has caused a new wave of COVID-19 infections in several countries, according to the Morning Post. But they found no trace of it in virus samples collected from people around the world. However, when they expanded their search to animals, they discovered some of the original B.117 forms in dogs, including one taken in the US last July. Such precursor variants include most or all of the original variant B117 in the Canidae breed, and they may re-infect humans after a period of rapid mutation. ”, Professor Chen Luonan and colleagues at the National Key Cell Biology Laboratory, wrote in an article published April 16. The appearance of the B117 variant has puzzled researchers. After being isolated from two patients in Kent County, southeast England, and London in September 2020, it quickly became the dominant strain of SARS-CoV-2 in the UK and many other countries, at a rapid rate. spreads faster than previous strains. Some experts believe this variant may emerge from local communities under pressure from antiviral drugs used during the pandemic. According to a popular theory, it suddenly appeared in Britain and then spread to other parts of the world. But variant B.117 has nine distinct mutations, rarely found in previous human strains – according to Professor Chen et al. These mutations do not occur in adjacent genes, but spread across the entire genome of the virus. The likelihood of all of these mutations appearing at once is extremely low. The Shanghai team believes that the above nine mutations are produced one after the other. Their model suggests that the variant may have originated outside the UK and received mutations on a non-human host. Dogs are the most suspect, followed by weasels or cats. However, Qu Liandong, professor of virology at the Harbin Veterinary Research Institute, who was not involved in the study, said more solid evidence is needed to support this theory. According to Qu, the strains found in dogs are not quite the same as the first strains identified in British patients. And although the number of genome sequences that researchers have globally reached in the hundreds of thousands, it is still small compared to the total number of patients there. 
If the dog is to be a host, “we’ll have a big problem.” Photo: AP Professor Qu, who studies infectious diseases in humans and animals, said that if pets like dogs become hosts, “we will have a big problem”. “Nearly all of our measures against the pandemic so far have taken into account people only. If the animal was involved, it would completely change the ‘game’, he said. When bird flu breaks out on a chicken farm, all chickens there must be destroyed, according to standard worldwide practice. If the disease can infect humans, all susceptible animals – including healthy ones – must be disposed of in the affected area. Dogs are close companions for humans, but if they are proven capable of carrying or creating mutant variants of the Sars-CoV-2 virus, they can also be destroyed, Professor Qu said. An alternative solution is to vaccinate animals. “But we can’t give the dogs human vaccines. We may need to develop some completely new versions. We have had a hard time vaccinating humans. How can the program be extended to both dogs or other animals? ”- Professor Gu raised the problem. There is growing concern that the B.117 variant could make dogs very ill. Veterinarians near London noticed a sudden increase in pets – including dogs and cats – with myocarditis earlier this year, and many of these animals tested positive for variant B. 117 – according to a Reuters report in March 2021. Another problem is, humans and animals have different immune systems and it is often difficult for viruses to spread from one species to another. The SARS-CoV-2 virus is thought to have originated in bats, but it can take decades to adapt to humans. When and where it made the animal-to-human transition is still unclear. Professor Chen’s team said that variant B.117 has a unique evolutionary strategy of increasing infectivity, so it can spread more easily from host to host, but at the same time reducing the number of copies it makes in the host. The researchers believe that whether this strategy helps variant B.117 overcome the species gap requires further study.
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