💯 even if true that variants get trade off lethality for transmissibility over time, a hypothetical variant that is 20% less lethal but 20% more contagious kills more people than the original virus (because cases compound → larger exposure → more total deaths)
(I didn’t check the estimate Giullaume quoted; here, I was just commenting on his general point.)
That said, I question the hypothesis that variants always trade off lethality for transmissibility. While I understand that more transmissible variants get selected, I don’t see why a variant couldn’t be both more transmissible and more lethal.
A bit exaggerated of an example, but it shows well my point above
Yes. Waves are partially due to seasonality, partially due to immunity fading / variants, and partially due to the virus filling a network fast📈, reaching herd immunity there📉, then finding access to another network📈
In the first tweet, by “the benefit/cost ratio increased”, I meant of vaccination. In other words, it’s more risky not to vaccinate now that it was a year ago, and it’s less risky to vaccinate now than it was in January.
(HT @maintcraft for pointing out the potential ambiguity)
This definitely matters (though I don’t know how much) and is usually missed by most models which – usual mistake – consider the population homogeneous.
If you asked if it matters, I’d say yes. I’d guess it explains a high percentage of wave behavior.
But if you asked me to list all causes, assign a percentage to each, and then normalize so that the total is 100%, I don’t think it’d be a very high %.
I hear that some think that an heterogeneous population has a lower herd immunity threshold, because the few superconnectors get infected first and stop connecting the groups.
But the superconnectors aren’t the only link between groups!
And probably reality is worse due to not having reach the top yet (probably)
For completeness: OTOH, the 75% vaccinated means that vaccinated cases contribute less to spread; OTOH, the asymptomatic vaccinated is also less likely to test, so in the numbers above I imagine that the two effects above cancel each other.
Take Italy: first wave was concentrated in Bergamo (North), if you lived in Southern Italy the chances that you knew someone that could infect you were very low.
But then cases diffused, and the chances you know someone you can take it from increase.
Apparently, there are COVID-parties in Austria, Germany, and NE Italy, where young people get together with infected thinking that “getting the virus is better than the vaccine.”
Terrible: not only it’s false, but they also create problems for everyone around them.
One thing is saying “I’m afraid of vaccine side effects so I use masks and other precautions to avoid getting sick” (legitimate)
Another things is saying “I proactively expose myself to the infected” (dumb)
Yes but proactively exposing yourself to a danger to (perhaps) avoid consequences from future exposures to the same danger is idiotic
(with a possible exception for controlled microdoses, but that’s not what’s going on here)