x Abu Dhabi, UAEMonday 22 January 2018

Camel antivenin project hit by funding shortage

A scheme to use camels to produce snakebite antivenins has had to be put on hold despite promising early results.

At Dubai's Central Veterinary Research Laboratory in March of last year, a catheter is injected into a camel's jugular vein so blood can be drawn from the animal during the antibody production process.
At Dubai's Central Veterinary Research Laboratory in March of last year, a catheter is injected into a camel's jugular vein so blood can be drawn from the animal during the antibody production process.

DUBAI // An innovative plan to use camels as four-legged factories for snakebite treatment has been put on hold despite promising early results.

The problem: a lack of funding.

"It's a shame," says the virologist Renate Wernery, "because the principle is magnificent."

The antivenins were developed last year using camel antibodies in the hope they could be used in Africa as early as next year to treat snakebites. They were being developed by researchers in the United Kingdom, and at Dubai's Central Veterinary Research Laboratory, among them Mrs Wernery.

She said testing of the antivenins - each is specific to a species of snake - had cleared its first two phases.

The first phase had found that camel antibodies were as effective as existing sheep and horse antivenins but were smaller, cheaper and could be stored unrefrigerated - making them an appealing substitute.

"You can carry this vaccine in your pocket, it's that easy," Mrs Wernery said. Not having to be stored cold would make any treatment far more useful in developing countries where refrigeration might be unavailable or unreliable.

Current treatments have a short shelf life, so hard-up hospitals in the developing world are often reluctant to order them. With few customers, big pharmaceutical companies largely stopped production a decade ago.

Another advantage of camel-derived antivenins over those extracted from sheep and horses is that camel antibodies are smaller - about a tenth the size. One of the problems with horse and sheep antibodies is that their large size hinders their movement through the human tissue wall, making them less able to stop the death of living tissue as toxins from venom spread.

The more compact camel antibodies are better able to get to where they are needed. They are also less dangerous than existing antibodies, which cause severe side effects in 15 to 30 per cent of patients, according to Dr Rob Harrison, the head of the Alistair Reid Venom Research Unit at the Liverpool School of Tropical Medicine. His lab milked snakes of their venom, which was then sent to Dubai to be injected into the camels, thereby provoking their system into producing antibodies.

Camel antibodies are "more tolerated by the human system, whereas the horse's isn't so good because it causes reactions in humans called anaphylactic shocks, which can then cause the same problems as the venom", Mrs Wernery said.

Anaphylactic shocks are allergic reactions that can cause loss of consciousness, laboured breathing, blueness of skin, low blood pressure, heart failure and death.

"Those are the effects that we were interested in reducing," Dr Harrison said.

The researchers successfully completed the second phase of the research, creating antivenins specific to individual snake species - such as the puff adder, the saw-scaled viper and the black spitting cobra - and testing them, safely and effectively, in mice.

Forty camels in Dubai were injected with tiny amounts of the toxins from snakes commonly found in Africa, using venom from Dr Harrison's lab. Over six months, the Dubai scientists extracted around 70 litres of antivenin serum, which was refined to seven litres of antivenin - enough to treat 1,000 snakebites.

The team was ready to go to the next stage of producing antivenins in quantity, having fitted out two laboratories with equipment worth Dh3 million to produce the antibodies needed for the treatment.

At that point, costs ground the project to a halt. "It became too expensive," Mrs Wernery said. "There was more than Dh1 million that still needed to be invested in it."

Since then the project has remained on hold, despite hopes of using the same technique to make vaccines for diseases such as polio, tuberculosis, malaria and HIV. "We haven't touched phase three yet and that involves clinical trials on humans in Africa."

Dr Harrison is among those left in limbo. "We haven't been able to secure the funds to do a clinical trial with the antivenins and we need that to move forward," he said. "The great shame about this research project is that we came up with what is potentially a very promising therapeutic lead but were not able to pursue it."