Why would an all-loving and all-powerful God create a world for us in which viruses exist?
Ever since the COVID-19 pandemic hit, this question has been one of the most frequent ones I’ve received both at my speaking and teaching events and on my social media pages. In previous Today’s New Reason to Believe articles, I describe the many crucial benefits we humans and all Earth’s life receive from viruses.1 To name just a few, viruses prevent Earth from becoming a bacterial slime ball, they contribute a large fraction of the “seeds” (aerosol particles around which raindrops form) needed for rainfall and snowfall, they contribute to maintaining the carbon, water, and oxygen cycles at the just-right levels essential for advanced life, and they enable engineers to make major advances in nanotechnology.
Now, four medical researchers at the University of Glasgow led by Megan Griffiths have demonstrated yet another benefit of viruses.2 They suggest using viruses to stop the spread of rabies to livestock, pets, and humans.
Current Rabies Control Methods
The currently used method to curb the spread of rabies (a preventable viral disease most often transmitted through the bite of a rabid animal) is through the large-scale distribution of vaccine-laden bait for wild and domesticated carnivores. This method has eliminated or substantially reduced the incidence of rabies in parts of North America and Western Europe.3 However, this approach is both expensive and labor-intensive.
In Latin America, vampire bats (see figure) are largely responsible for the spread of rabies. This spread results in substantial human suffering and death and the culling of valuable livestock herds.4 Presently, the management of vampire bat-transmitted rabies virus (VBRV) includes the wholesale killing of vampire bats usually through poisons, which often are ingested by other animals, and pre- and post-exposure vaccinations of humans and domesticated animals. Such management is expensive, labor-intensive, and not always effective.5
Figure: Vampire Bat
Credit: Ltshears, Louisville Zoo, creative commons attribution
New, Inexpensive, Effective Rabies Control Method
Griffiths’ team proposed and demonstrated the effectiveness of releasing a transmissible rabies vaccine into the wild vampire bat populations as a way to disrupt or wipe out rabies circulation. The advantage of such an approach is that it tackles rabies at the source.
First, Griffiths and her colleagues identified a candidate transmissible vaccine vector: Desmodus rotundus betaherpesvirus (DrBHV). This virus is (1) host-specific to vampire bats, (2) benign to the bats in that biologists can detect no deleterious consequences for infected bats, and (3) highly transmissible.
DrBHV ranks as a superinfection. It will spread through entire vampire bat populations once it is released to small numbers of individuals within the populations. Griffiths’ team performed simulations that showed that inoculating just one bat with a DrBHV, genetically modified to provide protection against a rabies infection, could immunize more than 80% of a bat population. Inoculating several bats could immunize 100% of a bat population.
Second, the team used deep sequencing data, applied a maximum likelihood framework, and developed mathematical models to test the prevalence of DrBHV on vampire bats living in five different ecozones of Peru. They concluded that “vaccination of key populations could not only reduce rabies outbreak metrics within that vaccinated bat colony but also trigger VBRV extinction at the intercolony level.”6
Griffiths and her fellow researchers showed that simply infecting a few vampire bats with DrBHV could eliminate the need to kill large numbers of bats and livestock and to vaccinate pets, livestock, and humans. It also circumvents protests and legal challenges from people opposed to this kind of vaccine. And it could be implemented for a tiny fraction of the cost and labor presently devoted to preventing and treating rabies infections. No needle injections, oral pills, or oral baits are necessary. This strategy would greatly reduce or eradicate death and suffering from rabies infections.
Application to Other Diseases
In another recently published paper, a team of six computational biologists led by Tanner Varrelman quantified the effectiveness of betaherpesvirus-vectored transmissible vaccines in controlling, curbing, or eradicating other diseases.7 They note that the spillover of deadly infectious diseases from wildlife and domesticated animal populations into humans is an increasing threat to human health and welfare and the global economy.
Varrelman and his research team used mathematical models and data from published field and experimental studies to show the effectiveness of infecting small numbers of wild and domesticated animals with genetically modified herpes viruses to prevent a broad range of deadly diseases from impacting humans and their livestock.
Every year, farmers around the world are forced to cull millions of livestock and domesticated birds to prevent the spread of deadly pathogens to other animals and humans. Thanks to the low virulence and high transmissibility of certain herpes viruses, these viruses can serve as vaccines to stop the spread of deadly diseases at their source.
These herpes viruses manifest multiple designs. They are able to infect their hosts with little or no consequence to the hosts’ health and welfare. They are highly infectious, able to be spread through an entire population through only a few infected individuals. They can be genetically modified, at little cost, by trained biochemists to serve as vaccines. The same biochemists can straightforwardly alter the genetic modifications to stave off mutated strains of diseases.
In addition, the herpes virus-vectored vaccines are easy and inexpensive to administer. There is no need to line up children, adults, or animals for vaccination. Biologists simply need to expose several animals to genetically modified herpes viruses.
These two research efforts provide evidence for the biblical notion that God has endowed his creation with resources that benefit humanity and other life. Human beings, as his image bearers, have been charged with the responsibility to find and use those resources wisely and compassionately.
Hugh Ross, “More Reasons to Thank God for Viruses,” Today’s New Reason to Believe (blog), Reasons to Believe, May 15, 2017; Hugh Ross, “Viruses and God’s Good Designs,” Today’s New Reason to Believe (blog), Reasons to Believe, March 30, 2020; Hugh Ross, “Benefits of Viruses,” Today’s New Reason to Believe (blog), Reasons to Believe, August 1, 2022.
Megan E. Griffiths et al., “Inferring the Disruption of Rabies Circulation in Vampire Bat Populations Using a Betaherpesvirus-Vectored Transmissible Vaccine,” Proceedings of the National Academy of Sciences USA 120, no. 11 (March 6, 2023): id. e2216667120, doi:10.1073/pnas.2216667120.
B. Brochier et al., “Large-Scale Eradication of Rabies Using Recombinant Vaccinia-Rabies Vaccine,” Nature 354 (December 26, 1991): 520–22, doi:10.1038/354520a0; Joanne Maki et al., “Oral Vaccination of Wildlife Using a Vaccinia-Rabies Glycoprotein Recombinant Virus Vaccine (RABORAL V-RG®): A Global Review,” Veterinary Research 48 (September 22, 2017): id. 57, doi:10.1186/s13567-017-0459-9.
Julio A. Benavides et al., “Quantifying the Burden of Vampire Bat Rabies in Peruvian Livestock,” PLoS Neglected Tropical Diseases 11, no. 12 (December 21, 2017): id. e0006105, doi:10.1371/journal.pntd.0006105; World Health Organization (WHO), Who Expert Consultation on Rabies: Second Report (World Health Organization, 2013), https://apps.who.int/iris/handle/10665/85346.
Daniel G. Streicker et al., “Ecological and Anthropogenic Drivers of Rabies Exposure in Vampire Bats: Implications for Transmission and Control,” Proceedings of the Royal Society B: Biological Sciences 279, no. 1742 (September 7, 2012): 3384–92, doi:10.1098/rspb.2012.0538.
Griffiths et al., “Inferring the Disruption,” p. 8.
Tanner J. Varrelman et al., “Quantifying the Effectiveness of Betaherpesvirus-Vectored Transmissible Vaccines,” Proceedings of the National Academy of Sciences USA 119, no. 4 (January 19, 2022): id. e2108610119, doi:10.1073/pnas.2108610119.