UAE-developed vaccine could end killer horse disease

Efforts to combat a deadly horse disease that has killed hundreds of thousands of animals are taking a step forward thanks to researchers in Dubai.

Scientists at the Central Veterinary Research Laboratory (CVRL) have developed what is thought to be the most effective vaccine yet against African horse sickness (AHS), a viral disease which can prove fatal to more than eight in 10 infected animals.

The disease has been known for nearly 800 years, but there is no effective treatment, making the creation of a reliable and safe vaccine all the more important.

Dr Ulrich Wernery, the CVRL’s scientific director, has seen animals infected with the condition and described it as “one of the worst equine diseases you can think of”.

“I had a dream when I saw these poor animals dying that I must do something,” he said.

Although vaccines against the disease have been used from as far back as the early 1900s, the vaccine most widely applied currently contains an attenuated or weakened virus that, on occasion, has mutated and turned virulent, killing vaccinated animals.

“It’s a good vaccine but in specific circumstances it can produce the disease,” said Dr Wernery.

The CVRL vaccine, however, uses inactivated viruses that are unable to become virulent again.

Clinical signs of AHS vary because there are several forms of the disease, but often infected animals develop a fever and breathing problems, with lung congestion eventually causing death.

Between 60 and 85 percent of horses that become infected go on to die from AHS, which was first identified in the year 1237.

The disease has never been found in the UAE, but the midges that transmit it are present in the Emirates. In previous decades there have been outbreaks in Saudi Arabia and Yemen.

AHS has also infected horses in Asian countries. Between 1959 and 1961, it caused an estimated 300,000 horse deaths in India and Pakistan. It remains endemic in sub-Saharan Africa.

The vaccine CVRL has developed is now being used in Kenya and Sudan, and appears to be effective at reducing infection rates.

“We have very good news just recently that Kenya has not one case of African horse sickness this year, most probably because of our vaccine,” said Dr Wernery.

“This is the first year that they didn’t have an outbreak, but they have previously reduced outbreaks because now everybody uses our vaccine. I believe we can eradicate the disease from parts of Kenya.

“It’s really a fantastic project and a great breakthrough in fighting this disease.”

The virus that causes AHS exists in nine serotypes – forms that cause a particular immune response in infected animals in terms of the antibodies produced – and the CVRL began identifying and isolating them in its laboratories in 2002.

It was not until 2014, however, that CVRL’s head of virology and senior scientist, Dr Sunitha Joseph, and her team completed the task of isolating all nine.

CVRL had to produce separate vaccines against each of the nine serotypes. Once this had been done, vaccine testing took place between 2018 and early 2019 on 29 retired race horses.

A PhD student at CVRL, Marina Rodriguez injected the horses - kept at a desert location in Dubai - with the vaccines and analysed their immune response.

A pair of horses was vaccinated against each of the nine serotypes and the remaining 11 animals were vaccinated against all nine, receiving the vaccine in two shots.

Each week blood samples were taken and tested for the presence of antibodies against the serotypes.

“We immunised the horses with the vaccine to study the serological response, the response of the immune system,” said Ms Rodriguez.

Horses vaccinated against just one serotype produced antibodies against only that serotype, while those vaccinated against all nine produced antibodies against them all, indicating the vaccine’s effectiveness.

The CVRL keeps stocks of the vaccine so that, in the unlikely event of an AHS outbreak in the UAE, horses can be vaccinated once the serotype causing the outbreak is identified.

“We have a vaccine bank with single serotype vaccines, and all nine mixed together,” said Dr Wernery.

“For example, if we have an outbreak here of serotype four, we’ll vaccinate against this serotype four.”

CVRL’s vaccine is currently produced only at the organisation’s laboratories in Dubai, but they are keen to find a partner in Africa who can carry out production there.

In January, Dr Wernery and his wife, Renate, a virologist, will travel to South Africa to meet officials and discuss the introduction of the vaccine in the country.

If the vaccine does become more widely used in Africa, it would benefit not just horses, but horse owners too.

“They are [often] small farmers; they are very poor. When one of the horses dies it’s a big, big loss for the family,” said Dr Wernery.

www.thenational.ae

Now why is this vaccine not available in SA?

That would be too easy Oscar

I give up honestly it’s just mind boggling.. where’s a response to this from NHRA? Phumulela? RA?
PS management AHS is back if you didn’t know!! Not even one comment as regards above on Sporting Post.. give up get out is the sign to me

....so who has gotten this hot potato now.....is this SAEF a new collaboration taking over from Racing SA/Ian Sanne/ or that bald Ozzie dude from CTS.....WTF is going on.....:huh:

......the long and short of it.....no one here is going to admit that our AHS vaccines and programme is flawed.... and that some our vaccinated horses have been affected and several have even died.....:oops:

It is well acknowledged by the SA Vets and scientists that the live vaccine that we have been using has its risks- hence the recent rules that the vaccine must be administered July- October and not in the peak months when the midges are most active. Well publicized work has been on the go for many years to develop an inert vaccine, both here and abroad.
Obviously there are significant commercial benefits to the developer of the first effective such vaccine.
The news from the UAE is fantastic, but this is brand new and like any new drug will need to be licensed in each jurisdiction before it can be used. Hopefully SA will move quickly and the vested interests of those doing similar research work here will not get in the way.
Most of the ( limited) outbreaks that have occurred in the WC free Zone over the past few years have been proven to have had their origin in horses vaccinated with the live vaccine, but it has still been the right decision to use the current vaccine in SA rather than do nothing and risk the losses of thousands of horses each year.
The issue of getting the EU to get off their arses and come and do the long awaited audit here to confirm that our surveillance and management protocols are effective ( which they now are thanks to the hard work done over the past 2 years) so that direct exports can resume is a separate political mess that the politicians, not the scientists, must resolve. Sadly, as has been reported, the horse industry is being used as a pawn by the EU in their efforts to dump chicken here despite their avian flu issues.

...yes Peter we hear you....but are you saying that horses that were affected were actually injected and the live vaccine led to their demise.....and that the miggie(midge) never found its way into the virus free vector.....:huh:

.....I was not really directly referring to the protocols but I know of several cases in Gauteng and KZN where horses died of AHS and were vaccinated.... yet the deaths and infections were never reported to be linked to AHS for fear that it affected the protocols for export......:blink:

......it is best that we really get our house in order ....and that there is no more a fractured effort dithering around with big excuses while taking home big salaries.....:ohmy:

If doing your job results in you becoming redundant once the task is complete, how enthusiastic would you be in getting that task done and dusted?

Asking for a friend

Over the Air wrote: If doing your job results in you becoming redundant once the task is complete, how enthusiastic would you be in getting that task done and dusted?

Asking for a friend

.....they would have been far better placed in solving the issues in the shortest possible time and while doing so won the admiration of most local breeders and international prospect buyers alike.....and if they had some of my skills they may have started a global supply bloodstock agency in the interim..:whistle: ...instead of appeasing a few breeders by networking with far less international buyers who could not export an iota and instead left them here to eventually throw in the towel.....:oops:

Muhtiman wrote: ...yes Peter we hear you....but are you saying that horses that were affected were actually injected and the live vaccine led to their demise.....and that the miggie(midge) never found its way into the virus free vector.....:huh:

.....I was not really directly referring to the protocols but I know of several cases in Gauteng and KZN where horses died of AHS and were vaccinated.... yet the deaths and infections were never reported to be linked to AHS for fear that it affected the protocols for export......:blink:

......it is best that we really get our house in order ....and that there is no more a fractured effort dithering around with big excuses while taking home big salaries.....:ohmy:

Horses that had Not been vaccinated in the free zone (which is normal if they are not planning to travel anywhere else) got infected, but the source was the vaccinated horses via the usual transmission vectors ( midges) in the window soon after vaccination when the traces of live virus in the vaccine can be transmitted.