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Trials to start for home-grown anti-venom
Researchers at the University of Peradeniya will next week begin clinical trials for new snake anti-venom that experts hope preclude the high rate of allergic reactions from imported medication.
Indian-manufactured anti-venom serum is the main weapon used against the 50,000-plus snake bites recorded annually in Sri Lanka but as venom varies in snakes of different countries the Indian anti-venom has limitations here.
As this paper reported recently, Indian anti-venom could cause adverse allergic reactions in 50-80 per cent of patients, with nearly half of these reactions life-threatening. Most Sri Lankan doctors see the solution (anti-venom) as a bigger challenge than snakebite itself.
“All laboratory tests have now been completed and the results show that the new anti-venom is far superior in terms of neutralising venom compared to the Indian anti-venom,” the team’s chief scientist, Professor Indika Gawarammana, said.
“After the safety and effectiveness of the new anti-venom is established following clinical trials, commercial manufacturing can be started.”
The research team received the first batch of the anti-venom processed by its collaborator, the Instituto Colodomiro Picardo (ICP) of the University of Costa Rica a few weeks ago and are now ready to begin clinical trials, said Prof.Gawarammana, who is Senior Lecturer at the Faculty of Medicine at Peradeniya.
The anti-venom is active against number of venomous snakes. The first test batch will be effective against venom from the cobra, Russell’s viper, saw-scaled viper and the hump-nosed viper (kunakatuwa). Anti-venom properties for the krait will, in time, be included in this serum.
The hump-nosed viper (Hypnale hypnale) is responsible for the highest number of snake bites in Sri Lanka and these can sometimes be fatal. Currently, there is no venom to treat kunakatuwa bites and victims are only treated with symptomatic treatment such as painkillers. Records show an unfortunate proportion of patients develop chronic kidney failure due to lack of an anti-venom.
The process of anti-venom development is complex. First, tiny amounts of venom are injected periodically into horses. Horses subsequently develop antibodies – a process similar to immunisation of children for various infections (polio, measles etc.) – in their blood.
These antibodies, the anti-venom, are then extracted, purified and freeze-dried for human use. If the purification is faulty the resulting substance could contain other serum proteins that could cause the problematic reactions coming from Indian anti-venom, Prof. Gawarammana explained.
The researcher recalls how the project began: “In October 2013, Ministry of Health of Sri Lanka invited Sri Lankan scientists, including myself, to produce safe and specific anti-venom for Sri Lanka.
“At our request, one of the best anti-venom producers in the world, Instituto Colodomiro Picardo (ICP) in Costa Rica, agreed to produce a test batch of Sri Lankan species-specific anti-venom at almost no cost,” Prof. Gawarammana said.
The ICP produces anti-venom for many South America and African countries and Papua New Guinea and these countries do not experience the problems seen in Sri Lanka from anti-venom. Recognising the value of the Peradeniya team’s work, the National Research Council of Sri Lanka provided part of the funding for the project. The rest of the funding came from Animal Venom Research International, a non-profit organisation based in USA.
The necessary permission to collect snakes and house them in a serpentarium, milk venom and export venom to Costa Rica was given by the Department of Wildlife of Sri Lanka.
The project was not without challenges. The team faced unnecessary delays due to adverse media publicity at the inception of the project. As well, researchers only received permission to collect snakes from home gardens to extract venom.
Prof. Gawarammana said ICP was ready to transfer the technology for making the anti-venom to Sri Lanka. He said the researchers do not mind who manufactures it as long as they realise their dream of seeing it save lives.