ETA: Trigger warning: this post contains real bad news and it also mentions deer hunting.
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🦌⚠️🦌 Deer Pandemic?! 🦌⚠️🦌 Scientists recently learned that TONS of white-tailed deer in the United States have SARS-CoV-2.
More than a few curse words were spoken by infectious disease epidemiologists upon hearing this news. It is very important and very, very bad news for our hopes of reaching herd immunity. It’s also worrisome in terms of possible viral variants.
ETA: If you’re heading out for deer season, you should definitely get vaccinated and wear an N95 mask at all times while handling/near anyone handling carcasses.
In a recent scientific paper, researchers from Penn State University reported their findings that SARS-CoV-2 (the virus that causes COVID-19 in humans) has spread widely in the white-tailed deer population of the United States. During one sampling period in Iowa (during the winter 2020 surge), 80% of the deer they tested were infected. And the variants circulating in deer were the same as in people, strongly suggesting that cross-species infection events happen often.
We don’t want to be overly alarmist, but this is real bad news.
Having *no* host besides humans is one of the prerequisites for any virus to be a candidate for elimination. Smallpox: No wild animal host. Polio: no wild animal host. Hepatitis: no wild animal host. Measles: no wild animal host.
SARS-CoV-2: animal host.
Deer-to-deer transmission and widespread infection in the deer community means there is now a wild animal reservoir of the virus, and there is currently no way to immunize a wild animal population.
So, with a wild animal reservoir of the virus out there, even after the pandemic has faded into history we will still have periodic new outbreaks of COVID-19 whenever a human is infected by a wild deer.
*Herd immunity* (ahem) will be much harder or impossible to achieve due to a steady trickle of deer-human interactions constantly reintroducing new cases of COVID-19 into the human population. The disease will likely become endemic in the United States in the same regions where white-tailed deer are common–at least until a solution is found to the problem of immunizing wild animals.
But wait, there’s also *really* bad news.
Whenever a virus commonly crosses species there is a heightened risk of viral mutations–potentially significant mutations. And the deer are already widely infected, so there’s nothing to be done on the prevention front at this point. That ship has sailed. This makes closely tracking variants both more important and more challenging. The United States has done a very poor job of tracking variants to date. If a significantly-enough different variant arises, the vaccines we have already gotten will start to lose some of their punch (but probably not all of their punch, so that’s something).
Currently, most states do not test deer for SARS-CoV-2. The good news, we guess, is that deer with the disease don’t seem to be very sick.
Watch this story. Its implications for the future course of the pandemic are huge.
Goats and Soda sum it up well.
US not doing a great job tracking variants
Refresh yourself on some infectious disease vocabulary:
