The Lumpy Skin Disease (LSD) virus that has killed at least 50,000 cattle in India this year is probably structurally different from the version of the virus that was prevalent in India in 2019, raising questions about whether to protect cattle. The new vaccine being developed may be sufficiently protective. ,
Scientists from Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology (CSIR-IGIB) and State Disease Diagnostic Centre, Jaipur analyzed five animals with symptoms of the disease and compared the genomes of the virus extracted from them. The six genomes (there were multiple genomes from the same animal) showed that it had “little similarity to the global genome” compared to genetic sequences from earlier outbreaks of the disease.
Analysis of the genome revealed 177 unique variants, none of which were found in four genome sequences from India related to the 2019 outbreak of the disease deposited in GenBank, a popular database.
“Analysis of viral sequences shows that genomes from the 2022 outbreak harbor a larger number of genetic variations than the reference genome and form a distinct lineage,” said authors Lenin Bhatt, Rahul C. Bhoyar, Bani Jolly, Ravi Israni, Hari Vignesh, Vinod Scaria, Sridhar Sivasubbu, say in their paper. The study appears on the preprint server Bioarxiv and has not yet been reviewed.
This is significant because Lumpy-ProvaKind, a vaccine developed by the Indian Veterinary Research Institute, and the Indian Council of Agricultural Research’s (ICAR) National Research Center on Horses, is based on LSD virus samples from cattle in Ranchi, hit by the 2019 outbreak. However, experimental trials with the vaccine on animals afflicted by the ongoing 2022 outbreak have yielded encouraging results, the ICAR and the agriculture ministry have said.
The vaccine is a live attenuated, or a weakened version of the virus that when injected into animals is expected to stimulate the immune system and protect against potential infection. Currently, the only vaccines available for this disease are goat pox and sheep pox, which are related to the LSD virus.
“It’s a million dollar question on what this genome sequencing means for a vaccine,” said Sridhar Sivasubbu of CSIR-IGIB and one of the scientists involved in the genome sequencing study.
This specific study, he said, did not shed any light because very few animals were tested and only a comprehensive sample of viral genomes spread across several states can answer what was identified and analyzed in Rajasthan as part of the study. Gone variants were widespread in India.
Another concern in the IGIB study is that one of the animals showed two distinct variants of the LSD virus when the virus was excreted from its nose as well as from the skin, suggesting that the virus appears to be able to develop. a single host. This again speaks of an increased infectivity of LSD virus in 2022 compared to 2019.
Lumpy skin disease is a contagious viral disease that is transmitted between cattle by direct contact with mosquitoes, flies, lice and wasps, and through contaminated food and water. The disease causes fever and lumps on the skin and can be fatal.
Symptoms include skin lumps about two to five centimeters across, high fever, decreased milk production, loss of appetite and watery eyes. The Center had recently said that around 57,000 cattle have died so far due to the disease spreading across Gujarat, Rajasthan, Punjab, Haryana, Uttar Pradesh and Andhra Pradesh.
The disease has raised concerns over its impact on the dairy business. India is the world’s largest milk producer with about 210 million tonnes annually.