UNDER THE MICROSCOPE
Rabies is a zoonotic disease, just like Covid-19. But it kills 100 percent of its victims, compared to less than two percent for Covid-19. Worldwide, rabies kills 60,000 people annually. WHO says it is probably underestimated. In the Philippines, between 200 to 300 die of rabies each year. The economic costs include animal-bite treatment, called post-exposure prophylaxis (PEP), for over 1.2 million persons a year, and pre-exposure prophylaxis (PREP) in high-risk areas, especially children, who are most prone to animal bites.
Sadly, it is a neglected disease. Yet it is 100 percent preventable through an effective mass dog-vaccination campaign, since 99 percent of human rabies is from rabid dogs. This is another instance of the efficacy of vaccination, either human or animal, no question about it.
In 2021, however, the Philippines failed to reach its target of becoming a rabies-free country, with 231 persons succumbing to the dreaded disease that year. While the DOH has been waging a campaign with its Rabies Prevention and Control Program, we need to take a more critical look at its various components.
The program objectives are spot-on, though the means to its end point should be scrutinized to ensure effective implementation. We are constrained by lack of personnel and other resources, which can be overcome by more efficient utilization based on current science.
It is said that the 1:10 dog-to-human ratio is a gross underestimation, based on some studies which find it closer to 1:3 or thereabouts. This datum is crucial, as we have to vaccinate at least 70 percent of all dogs to eliminate the menace of rabies. So, even if we target vaccinating 70 percent of dogs based on a 1:10 ratio, it will fall short of the target.
Dog-rabies vaccines are now formulated to be effective for three years. But manufacturers do not formally endorse their rabies vaccines as effective for that long, mainly because it will be a loss of income for them if dogs are vaccinated only every three years. Neither is it good for veterinarians, who derive income from annual vaccinations. But in fact, there is research that shows rabies vaccines can be effective up to five to six years (see The Rabies Challenge Fund research study, Can J Vet Res 2020 April).
The Philippine rabies-control program still adheres to the annual rabies vaccination for dogs, as does the veterinary association. This doesn’t make good sense for a national program with limited resources. This is just like running after an elusive target year after year when we haven’t even managed to do it in one year. Yet the current science says we can achieve good rabies control even with just 70 percent of all dogs getting a single rabies shot.
Considering current realities, when what we’ve been doing year after year hasn’t worked, here’s a plan that might possibly help – and you know what they say if you keep doing the same thing and expecting a different result.
What if: We aim to vaccinate all dogs in each locality (in conjunction with LGUs) and at the same time microchip them? This would give us the ability to track dogs based on their being microchipped, ergo, vaccinated for rabies. Any dog in that locality that doesn’t have a microchip is assumed to be unvaccinated and can be targeted for vaccination, eventually achieving 100 percent coverage. This will help in the removal of stray dogs from the community, since non-microchipped dogs will be assumed to be owner-less and can be impounded to reduce the occurrence of dog bites, which are mainly from strays.
Surely, this proposal will be more attainable than the yearly requirement for dog vaccinations. Attention can then be focused on the young unvaccinated dogs that were born previously, since efforts on spay/neuter campaigns may not be well received in the community for economic reasons. People breed dogs, often indiscriminately — even mongrels — as potential money earners.
The above plan is based on the WHO Control of Neglected Tropical Diseases, and I quote:
“However, if the effective immune period of the vaccine is longer and the system for identifying vaccinated dogs can be trusted to last more than one year, the advantage of vaccinating only the dogs entering the population after the last campaign should be considered, with revaccination of dogs vaccinated during the last campaign at intervals of about two years.”
The Strategic Plan states the goal of eliminating rabies in the Philippines by 2030. The Department of Agriculture Bureau of Animal Industry (BAI) as the lead agency should take another look at its plans if we are to achieve the goal post, which has been reset again and again. The savings from the PEP and PREP obtained through reduced rabies transmission can be used for the continued implementation of the mass dog-vaccination program, which is really its cornerstone.
