Vaccinate people or vaccinate dogs?

A new research study undertaken by GARC and recently published in PLoS ONE has quantified the benefits and the limitations of relying on the provision of human vaccine to prevent deaths from dog transmitted rabies. These new findings are of great significance to all rabies endemic countries hoping to reach the global goal of zero human deaths by 2030.

In this new study, members of the GARC Philippines office interviewed community members, animal bite treatment center patients, and local and national government personnel who implement the rabies vaccination program on the distribution of human rabies vaccine after a suspected rabid dog bite. This comprehensive approach has allowed the first complete picture of the provision of human rabies vaccine in the Philippines, from both a health service and a patient perspective.

When someone is bitten by an animal in a country like the Philippines, a very real concern is that they may develop the fatal disease rabies. Once symptoms develop, there is no treatment for rabies, and the patient will suffer horrendous anxiety and agonizing neurological symptoms until they lapse into a coma and die.

Fortunately, an excellent human vaccine is available that can prevent rabies symptoms from developing in people, even after they have been bitten by a rabid animal. This makes the provision of this life-saving vaccine critical for over 100 countries worldwide where rabies is uncontrolled in dogs.

The Philippines has long been an excellent example of a health care system that provides rabies vaccinations across the entire country, despite the complexity of servicing over 2,000 inhabited islands. It was amongst the first countries in the world to adopt a cost-saving technique called intradermal delivery for vaccination that requires far less vaccine than the traditional route.

The study documented the expansion of the Philippines’ national network to over 500 animal bite treatment centers. These clinics provide vaccine free of charge to patients who have been bitten by an animal, making them one of the most accessible human rabies vaccination programs in the world.

In villages surveyed, over 80% of households were aware of the location of the nearest bite treatment center, indicative of a highly effective awareness program. However, the study surveys also revealed that across sites, between 4.2 and 6.7% of the population were being bitten by dogs every year. Nationally, demand for vaccine has been growing fast as availability has improved. The Philippines government treated over 1 million patients with vaccine to prevent rabies in 2016 at an estimated cost of 37.6 million USD, and vaccine shortages were reported at times when demand exceeded supply.

Despite this massive delivery program, 260 human deaths still occurred in 2016. The explanation lies in the fact that although awareness of the availability of vaccine is high and that the costs of seeking treatment were not usually prohibitive, only 45% of animal bite victims sought medical attention. Instead, traditional healers were still frequently sought out for bite treatment in 2 of the 3 project sites.

The program is highly cost effective but not perfect, and costs look to continue to rise steeply with time, unless something dramatically changes. So what can be done?

Dogs bite for a variety of reasons, and a simple follow up with patients interviewed in the clinics revealed that over 85% of those patients who receive vaccination were not actually exposed to rabies. The problem is that reliable ways to identify those bite victims who are at risk of developing rabies are not yet incorporated into the treatment protocols. Work to reduce unnecessary use of post-exposure prophylaxis (PEP) is just beginning and will be vital to sustaining the provision of human vaccine in many countries.

But the real necessity is to dramatically increase the use of dog rabies vaccines to eliminate the virus in the dog population and, therefore, to end the public health threat. The choice of alternative methods of rabies control has been a conundrum for countries for many decades. Whilst money, often significant amounts, is spent on human vaccines, it is often hard for governments to find additional resources to vaccinate dogs. Vaccinating dogs can also be a considerable challenge, especially when there are large populations of free-roaming dogs that don’t live very long.

However, with a global goal set for the elimination of human rabies deaths by 2030 and with the momentum to build the capacity to reach this goal, it is time to rise to the challenge and do what we know will end this terrible disease forever. A well-cared for, vaccinated dog population will protect everyone in the community.

Contributed by Louise Taylor. The study was published in July 2018, in two papers in the journal PLoS ONE, accessed here and here. The Global Alliance for Rabies Control (USA) received funds from GlaxoSmithKline Biologicals SA (Belgium) to undertake the study.