> Ferrets are a common model for studying how influenza viruses that primarily affect birds are able to adapt to mammals, a topic that Kawaoka and his colleagues at UW–Madison’s Influenza Research Institute investigate since such a jump could trigger an influenza pandemic.
Several million similar infections can easily mutate into something worse.
What is bad is its novelty to our immune system, not necessarily its initial mortality rate.
It was a series of overreactions in the media to studies like this one that led me to be skeptical of the news reporting about COVID in its early days. I came around, but a lot of others didn't. Overblown health scare headlines cause real harm for science communication.
What this shows is that the virus is able to jump the barrier to mammalian lung cells with a few iterations, and already has by way of some human exposure. There is no particular reason to think that a lung infection in humans wouldn't be 100% lethal as it is in ferrets or sea lions. So far, the only infections in humans in the US that we know of have been essentially relegated to the eyes. But it appears that the virus is primed for more than that now.
I'm not suggesting that the media go crazy causing a panic, or that the media do anything at all, since they only seem to inflame every situation. But looking at the data from this report, I think it is reasonable to assess that we're on a tragectory toward a highly lethal airborne H5 virus, and take appropriate steps to shore up vaccines and antiviral stocks.
I take your point, that the suggestion in that case study is that the virus caused it directly (RTPCR from the conjunctiva tested positive for the virus). He did have a full-blown case of conjunctivitis, though.