Ahmedabad: Clinical trials have started on small animals for the country’s first indigenously-developed vaccine against Canine Distemper Virus (CDV), which infects big cats including lions. The Gujarat Biotechnology and Research Centre (GBRC), which has developed the vaccine, plans to roll it out this year to check the CDV among Asiatic Lions. Trials can later be done on leopards and tigers, said two officials familiar with the matter.

GBRC has joined hands with Hester Biosciences, an Ahmedabad-based animal healthcare company, for the commercial rollout of the vaccine. CDV results in encephalitis and pneumonia and was found in dogs earlier. Over the years, it has spread to the wild cats.
CDV is said to be responsible for wiping out nearly one-third of the 3,000 lions at Tanzania’s Serengeti National Park in 1994. The virus also killed 30 lions in two months in 2018 at Gujarat’s Gir National Park, the last abode for the endangered species.
In 2020, there was another CDV outbreak at Gir. An environment ministry committee found 85 lions died over six months. It did not mention CDV as the cause of the deaths but recommended expediting the development of the vaccine against it. There was a 29% rise in the number of lions in Gujarat to 674 in 2019 compared to 523 in 2015.
A state government official said GBRC has achieved a breakthrough in its research and is conducting trials on guinea pigs and mice for the vaccine. “The efficacy of the vaccine is found to be high at more than 80% as per initial results.”
{{/usCountry}}A state government official said GBRC has achieved a breakthrough in its research and is conducting trials on guinea pigs and mice for the vaccine. “The efficacy of the vaccine is found to be high at more than 80% as per initial results.”
{{/usCountry}}The state government is backing the vaccine project and has approved ₹50 lakh for it. GBRC has been established under the government’s department of science and technology to undertake biotechnology research in priority areas.
A GBRC official said they have sought the forest, environment, and climate change ministry’s permission to begin trials on zoo lions. He added they have also approached the Drugs Controller General of India for the commercial rollout. “The trial is likely to be carried out on five to six lions.”
The commercial production of the vaccine will start after it gets all necessary approvals at Hester’s plant near Ahmedabad. “This is for the first time in India that any state government or its department is working on a vaccine for wildlife. Earlier such initiatives have been taken for poultry, cattle, sheep, and other domestic animals. We have collaborated with GBRC for the commercial rollout of the vaccine,” said Hester Biosciences CEO and MD Rajiv Gandhi.
GBRC offered diagnostic services in 2018 after the first CDV outbreak among Gir lions. “During genome sequencing, we found the virus strain was different by about 6.6% than the reference genome of CDV. It is a very significant variation. Hence, we decided to develop an indigenous vaccine for Asiatic lions. This will be the first CDV vaccine in the world for the Felidae family. We aim to roll out the vaccine this calendar year,” said a second GBRC official involved in the project.
A team of GBRC researchers and scientists found the fatality rate due to CDV during the 2018 outbreak was very high. A serosurvey found the presence of CDV in all the tissues. Serosurveys estimate antibody levels against infectious diseases and are used for measuring immunity levels due to past infection or vaccination.
The state forest department imported purevax ferret distemper vaccine from the US for the Asiatic lions then. This was after the Indian Council for Medical Research in October 2018 recommended the existing CDV Vaccine should work as a protective intervention for Gir lions.
Thirty-three lions from Gir were captured and quarantined for vaccination. Four years later, their reintroduction to their natural habitat remains uncertain. Challenges remain for vaccinating 80% of the lion population as the animals will have to be captured for vaccination, said another government official. “Catching such a large number of big animals is not easy,” he said. He added after the first dose of vaccine, the second is to be administered before booster doses can be given annually if required.
Wildlife Institute of India dean Y V Jhala said CDV is very active and can prove fatal for lions. He called research on the vaccine for lions good but added the government should also consider an alternative home for lions outside Gir. “Gujarat should spread its risks so that the population does not wipe out in case of an epidemic. There are many places in Gujarat, far away from Gir that can serve as an alternative home for lions.”