Good post, and this also seems to be a very opportune time to be promoting wild animal vaccination. A few thoughts:
To start with, programs of this kind would only be implemented after a vaccine is developed and distributed among human beings.
In relation to the current pandemic, the media often mentions that there are 7 coronaviruses that can effect humans and we don’t have an effective vaccine for any of them. However, I was recently surprised to learn that there are several commercially available veterinary vaccines against coronaviruses—this raised my expectation that a human coronavirus vaccine could be successfully developed and seems promising for animal vaccination as well.
I think it’s worth thinking more about what level of safety testing goes into developing animal vaccines. The Hendra virus vaccine for horses might be an interesting case study for this. Hendra virus was relatively recently discovered in Australian, and can be transmitted from flying foxes (a megabat species), via horses, to humans where it has 60%+ case fatality. Fruit bat culling was very widely called for after a series of outbreaks in 2011, but the government decided to fund development for a horse vaccine instead (by unfortunate coincidence, a heat-wave latter killed 1/3rd of the flying fox population a few years later). A vaccine was developed within a year and widely administered soon after. However, some owners (particularly those of racing horses) reported severe side-effects (including death) and eventually started a class-action against the vaccine manufacturer. I don’t know if the anecdotal reports of side-effects stood up to further scrutiny (there could have been some motivated reasoning going on similar to that used by human anti-vaxxers), but it seems plausible that veterinary vaccine development accepts, or does not even attempt to consider, much worse side-effects that would be approved in a vaccine developed for humans. Given animal’s inability to self-report, some classes of minor side-effects may only be noticed by owners of companion animals who are very familiar with their behaviour. While I don’t think animal side-effects would be a consideration in developing vaccines for pandemic control or economic purposes, it seems more relevant in the context of vaccinating animals to increase their own welfare.
This may be the case especially for bats, because they have one of the highest disease burdens among wild mammals. Among other conditions, they are harmed by a number of different coronaviruses-caused diseases. In fact, they harbor more than half of all known coronaviruses.
Why do bats have so many diseases (lots of which humans seem to catch)? This comment (which I found in an SSC article) frames the question in another way:
There are over 1,250 bat species in existence. This is about one fifth of all mammal species. Just to get a sense of this, let me ask a modified version of the question in the title:
“Why do human beings keep getting viruses from cows, sheep, horses, pigs, deer, bears, dogs, seals, cats, foxes, weasels, chimpanzees, monkeys, hares, and rabbits?”
This re-framing doesn’t really change the problem, but it suggests that just viewing ‘bats’ as a single animal group comparable to ‘cows’ or ‘deers’ is concealing the scope of species diversity involved.
I heard Jonathan Epstein talk at a panel discussion on biosecurity last year. He was in favour of disease monitoring and management in wild animal populations, and also seemed sympathetic to the idea of doing this from both a human health and animal welfare standpoints. He might be interested in discussing this further, and is in a position where he could advocate for or implement these ideas.
Thank you for your excellent comment, Gavin! You highlight several important points, with which we agree. Concerning why viruses in general, and coronaviruses in particular, are so prevalent in bats, you’re quite right, although on top of what you said there are other factors that can be considered too, which is why we argued that it could be a sum of “high genetic diversity (there are both many species and many individual bats), [and that bats are] long-lived, and they roost in large groups.”
Good post, and this also seems to be a very opportune time to be promoting wild animal vaccination. A few thoughts:
In relation to the current pandemic, the media often mentions that there are 7 coronaviruses that can effect humans and we don’t have an effective vaccine for any of them. However, I was recently surprised to learn that there are several commercially available veterinary vaccines against coronaviruses—this raised my expectation that a human coronavirus vaccine could be successfully developed and seems promising for animal vaccination as well.
I think it’s worth thinking more about what level of safety testing goes into developing animal vaccines. The Hendra virus vaccine for horses might be an interesting case study for this. Hendra virus was relatively recently discovered in Australian, and can be transmitted from flying foxes (a megabat species), via horses, to humans where it has 60%+ case fatality. Fruit bat culling was very widely called for after a series of outbreaks in 2011, but the government decided to fund development for a horse vaccine instead (by unfortunate coincidence, a heat-wave latter killed 1/3rd of the flying fox population a few years later). A vaccine was developed within a year and widely administered soon after. However, some owners (particularly those of racing horses) reported severe side-effects (including death) and eventually started a class-action against the vaccine manufacturer. I don’t know if the anecdotal reports of side-effects stood up to further scrutiny (there could have been some motivated reasoning going on similar to that used by human anti-vaxxers), but it seems plausible that veterinary vaccine development accepts, or does not even attempt to consider, much worse side-effects that would be approved in a vaccine developed for humans. Given animal’s inability to self-report, some classes of minor side-effects may only be noticed by owners of companion animals who are very familiar with their behaviour. While I don’t think animal side-effects would be a consideration in developing vaccines for pandemic control or economic purposes, it seems more relevant in the context of vaccinating animals to increase their own welfare.
Why do bats have so many diseases (lots of which humans seem to catch)? This comment (which I found in an SSC article) frames the question in another way:
This re-framing doesn’t really change the problem, but it suggests that just viewing ‘bats’ as a single animal group comparable to ‘cows’ or ‘deers’ is concealing the scope of species diversity involved.
I heard Jonathan Epstein talk at a panel discussion on biosecurity last year. He was in favour of disease monitoring and management in wild animal populations, and also seemed sympathetic to the idea of doing this from both a human health and animal welfare standpoints. He might be interested in discussing this further, and is in a position where he could advocate for or implement these ideas.
Thank you for your excellent comment, Gavin! You highlight several important points, with which we agree. Concerning why viruses in general, and coronaviruses in particular, are so prevalent in bats, you’re quite right, although on top of what you said there are other factors that can be considered too, which is why we argued that it could be a sum of “high genetic diversity (there are both many species and many individual bats), [and that bats are] long-lived, and they roost in large groups.”