By Douglas Coulter

Our partners over at the Belgium-based organisation Health for Animals have been highlighting the importance of immunisation recently under the theme of vaccines that are ‘changing the world’ to coincide with National Immunization Awareness Month – currently running in the US throughout August.

Their recent blog post Five immunizations that are changing the world includes three livestock diseases that feature among GALVmed’s portfolio of development projects – Brucellosis, Peste de Petits Ruminants (PPR) and Porcine Cysticercosis (PC).

Here at GALVmed, we work with our partners, including Health for Animals, to make livestock vaccines, medicines and diagnostics accessible and affordable to smallholder farmers in Africa and South Asia. To celebrate National Immunization Awareness Month and our partnership achievements in vaccine development we’re providing an update on where we are with our Brucellosis, PPR and PC  projects.

Brucellosis – US $30 million vaccine prize competition for new vaccine

Creating a buzz in the veterinary press recently was the announcement of the first three prize winners each awarded US $100,000 following their initial application to the AgResults’ – a global US $30 million competition aimed at incentivising vaccine developers to develop an efficacious, safe and viable vaccine for use against Brucella melitensis in sheep and goats in the developing world.

Brucellosis is a costly disease that affects ruminants – cattle, sheep, goats, buffalo, etc. – and causes abortions, infertility, decreased milk production and weight loss, amongst other effects. It is endemic in a number of developing countries, and the toll on smallholder farmers in South Asia and sub-Saharan Africa is particularly devastating, since cattle and small ruminants, such as goats and sheep, are a crucial source of income.

The annual impact of Brucellosis to smallholders across sub-Saharan Africa and South Asia is estimated at USD $500 million per year.

Brucellosis is also the most common type of disease that is transmitted from animals to humans, with approximately 500,000 new human cases reported each year.

The Brucellosis Vaccine Prize is designed, funded and managed by AgResults – a collaborative initiative between the governments of Australia, Canada, the United Kingdom and the United States as well as the Bill & Melinda Gates Foundation. It invites vaccine developers to submit their proposals for the development (and ultimately registration) of a suitable vaccine that is efficacious, safe and viable for use against Brucella melitensis in small ruminants across the developing world. Implemented by the Global Alliance for Livestock Veterinary Medicines (GALVmed), the competition involves three phases and can run for up to 10 years.

Read about the first set of prize winners and more about the Brucellosis Vaccine Prize, which is accepting applicants to Phase 1 until 18 November 2017.

 Peste des Petits Ruminants – a new combined vaccine

Also of great economic significance to smallholder farmers is the viral small ruminants disease Peste des Petits Ruminants (PPR), which is estimated to cost US $874 million per annum.

GALVmed’s objectives in tackling PPR include assisting in wider registration in Africa of a PPR vaccine, completing vaccine thermotolerance work and developing a multivalent vaccine potentially covering PPR and other diseases of small ruminants such as Sheep and Goat Pox (SGP) and Rift Valley Fever.

In 2016 GALVmed supported MCI Santé Animale, a Morocco-based animal health company, to test the field acceptance of a combined PPR/SGP vaccine. The combined vaccine has been named LYOPOX-PPR®. The test was carried out in three African countries – Mali, Tanzania and Uganda – and also involved deworming of sheep and goats. A similar test is being carried out in Kenya on a commercial basis to gauge its acceptance with the livestock-keeping community. Traditionally, governments provide vaccines during outbreaks to prevent spread of the two diseases. By combining the two vaccines into one, the livestock keeper will have a tool to control the two diseases in one move. By the time a disease outbreak is apparent, it is usually too late for the affected community.

Porcine cysticercosis: First-ever licensed disease against major cause of epilepsy in developing world

A key breakthrough in tackling Porcine Cysticercosis (PC) came last year with the announcement of the first-ever licensed vaccine for the disease developed by Professor Marshall Lightowlers at the University of Melbourne.

PC is a neglected disease caused by the parasitic worm Taenia solium in  pigs. It is most commonly found in Latin America, Southeast Asia and Africa and is most prevalent in rural areas where pigs are allowed to roam freely.

Humans can be infected when they accidentally ingest infected pork (which leads to an intestinal infection) or infective eggs, which leads to neurocysticercosis, an infection of the nervous system that causes epilepsy and is the main cause of acquired epilepsy in the developing world. The disease is a serious public health and agricultural problem and causes around five million human cases and 50,000 human deaths each year.

Following the announcement, Professor Lightowlers said: “The publication of results from a trial undertaken to eliminate Taenia solium transmission from the Tumbes region of northern Peru represents an important step in the prevention of epilepsy caused by parasitic infections.

“The contribution of the TSOL18 vaccine for pigs was found to be critical to achieving the highest level of disease control.

“Our challenge for the future is to develop an effective strategy for use of the vaccine in the many poor communities around the world where this parasitic disease is prevalent.”

The TSOL18 vaccine technology, known as Cysvax®, is on sale in India through is the first step towards expansion of the vaccine licensing in other countries as licensing in the country of manufacture is typically a prerequisite to other country licences.

GALVmed is also working with partners in Uganda, Tanzania, Zambia, Nepal  and India in pilot projects in PC vaccination and deworming to raise awareness of the disease and the vaccine.

Commenting on GALVmed’s work on the field of immunisation, Health For Animals Executive Director Carel du Marchie Sarvaas said: ““It has been incredibly encouraging to witness GALVmed’s progress in recent years. Diseases like Brucellosis are often forgotten in regions where it has been controlled, while it remains endemic and devastating across South Asia and sub-Saharan Africa.

“GALVmed is filling an important void in encouraging the development of new tools that we can use to fight these diseases that will save not only the lives of animals, but humans as well.

“Successful medicines will prevent zoonotic disease transmission and provide a path out of poverty for millions across the world.”

We will continue to update you on these and other projects.  Check our blog regularly or sign up to our bimonthly newsletter at the bottom of the home page.

A simple diagnostic device is enabling farmers in Cameroon to test for the deadly livestock disease Animal African Trypanosomiasis (AAT or Tryps).

AAT is caused mainly by two parasite species, Trypanosoma vivax and Trypanosoma congolense, which affect cattle in much of sub-Saharan Africa. However, according to veterinary experts, a new rapid field test can identify whether or not an animal is infected with the T. congolense or T. vivax strain through a single drop of blood, reducing the occurrence of misdiagnosis and helping farmers avoid costly expenditure on unsuitable treatments. Prior to the test, animals were only treated for AAT after showing vague clinical signs of the disease, which can be easily confused with other common problems such as tick-borne diseases, and often result in the use of the wrong product for the wrong disease. However, due to the test’s quick results, farmers do not need to wait for the appearance of clinical signs before treating the animal.

AAT is a major limiting factor in the development of animal production in Cameroon – as it is throughout the rest of sub-Saharan Africa. The disease is endemic in 40 African countries and accounts for up to a 50 per cent loss in milk and meat production on the continent. According to the Food and Agriculture Organization of the United Nations, losses associated with the disease in Africa are estimated at between US $1 and 5 billion annually. Clinical signs for AAT include weakness, lethargy, anaemia and fever, which lead to weight loss as well as fertility and milk reduction. However, symptoms alone do not allow for an accurate diagnosis, and diagnostics for AAT parasites are limited or may not produce accurate results.

Partnering for a practical solution

To address this issue, the Global Alliance for Livestock Veterinary Medicines (GALVmed) – a non-profit company that makes livestock vaccines accessible and affordable to smallholder farmers in Africa and South Asia – has worked with Ceva, the University of Bordeaux, the French research agency CIRAD and teams of researchers throughout East, West and Southern Africa to develop the first available rapid field diagnostic test against animal trypanosomosis in the world. This test, called VerY Diag, is able to quickly detect infection with the T. congolense and T. vivax strains.

GALVmed’s partner, major international animal health company Ceva, is now leading the initiative to increase the availability and reach of VerY Diag, which is now used in the Littoral, West, Northwest and Northern regions of Cameroon.

“The test now allows millions of smallholder cattle farmers an efficient way to test their cattle and provide the right cure,” says country representative, Dr Fidele Marcel Abena of Ceva Animal Health. The affordable device, does not require electricity or any additional equipment, making its deployment in resource-limited settings very practical.

Increasing incomes for livestock keepers

Many farmers attest to the rapid field test’s ease of use and effectiveness in protecting cattle health. Since the launch of the diagnostic in October 2016 by Ceva, farmers have been able to identify the right treatment for their cattle. As a result, cattle are producing more milk and achieving higher market prices. “Before, most of my cows did not look healthy, weighing below 250 kg and forcing me to sell them at the give-away price of less than 200,000 fcfa (US $340) but now I am proud to see my cows weighing over 300 kg and selling at 300,000-400,000 fcfa (US $500-680),” says Amadou Djibrilla, a farmer from Ngaoundere in the Adamawa Region of Cameroon.

“This innovation has given farmers a plus, it is like health security for our cattle,” says Aboubakary Hamadou, a cattle farmer also from Ngaoundere. In 2012, Hamadou lost over 50 cows and another 26 in 2015 due to misdiagnosis and ineffective treatment of AAT. Since utilising the test prior to applying treatment, he has not lost a single animal.

“It is a great relief for us that diagnostics now exist for farmers to test their cattle prior to applying medicines, helping us to avoid unnecessary financial waste and better protect our resources,” says Abbo Mohamadou, a cattle farmer of Ngaoundaba Ranch located 35 km from Ngaoundere. “Without the test, we used to incur great financial losses but now the situation has significantly improved,” states Mohamadou.

Handing back control to smallholder farmers

As the VerY Diag test uses antibody detection technology to enhance test ‘sensitivity’ (the ability to identify infected individuals correctly) and reduce false negative results, the test is able to detect the presence of antibodies within a few days of infection.

According to Dr Ibrahima Djibo, a support staff member at Ceva’s Cameroon office, “The test process is simple – taking a drop of blood and mixing it with a drop of reagent on the device. The red blood cells from the samples will be trapped by some of the test elements. If animals are infected, antibodies against the Trypanosome parasite will trap the parasite in the test at the ‘Tv’ or ‘Tc’ line. This will lead to the appearance of a red band (indicating a T. vivax or T. congolense infection). If animals are not infected, the red band does not appear. The results are ready in just 10-15 minutes and reading of the test results is simple and easily understood by farmers,” says Dr Djibo.

“It is important to act and treat AAT properly and as soon as possible, even before the appearance of clinical signs to save farmers the economic losses associated with reduced milk and reproductive capacity as well as reducing heavy treatment costs when the clinical disease was initially misdiagnosed and follow-ups were required,” says Dr Cyrille Chevtzoff, Ceva’s ruminant technical and marketing manager for inter-tropical Africa. “It takes time for the cattle to recover their initial weight after treatment (up to several months) during which, the animals will require extra feeding.”

By providing farmers with rapid and accurate results, the diagnostic is effectively handing back control to the smallholder farmers whose quality of life has been affected by this disease and is a clear example of the importance of GALVmed’s focus and its partners’ work.

(Written by Elias Ntungwe Ngalame. Photos provided by Cyrille Chevtzoff of Ceva.)