4 ms·
Which was projected to be the trajectory from the start. Transmissible diseases usually mutate to be less deadly over time, because killing the host is a bad r
by paulmd 3y ago
Which was projected to be the trajectory from the start. Transmissible diseases usually mutate to be less deadly over time, because killing the host is a bad reproduction strategy. Spanish Flu is still here today, it's just not crazy deadly anymore.
It's just not guaranteed to be monotonic (particular strains can bump lethality upwards), and it doesn't help the people who die early on to the stronger strains, especially with an overloaded medical system.
Like, we don't have hospitals overflowing into makeshift tent farms outside with freezer trucks used to handle the overload of bodies until the crematoriums can get around to them anymore, either. It's definitely trended towards reduced lethality over time.
- soperj 3y agoAre you saying AIDS has gotten less deadly over time?
- deleted 3y ago[deleted]
- datadeft 3y agoYes. The latest variants are less deadly. There is a pretty good reason for that. If the infected lives longer it has a higher chance of a successful transmission.
- soperj 3y agoWhat are you basing this on? Looks like deaths peaked in 2004, but more people in Africa are receiving treatment. Without treatment the avg life expectancy seems to be 11 years, and doesn't look like that's changed.
- datadeft 3y agoI think there are several factors in when the deaths peaked. https://www.bbc.com/news/health-30254697 https://www.bbc.com/news/health-30254697
- MichaelZuo 3y agoCan you link to a source?
- datadeft 3y agohttps://www.bbc.com/news/health-30254697 https://www.bbc.com/news/health-30254697
- FredPret 3y agoI think it actually has - AIDS is the worst but life expectancy has improved a lot
- ebiester 3y agoIf you take into account the lifecycle of HIV, it can take 2-15 years to develop stage 3. (Stage 3 is the symptomatic part. People on medication may never reach stage 3.) As such, a transmission generation even of SARS-CoV-2 is going to be on the order of days. HIV can be on the order of years. So, there are different evolutionary pressures. If we find out that Covid is actually latent in all of us years later (unlikely because we would have likely seen it with SARS-1 or MERS), then all bets would be off.
- soperj 3y agoThis makes sense. Would also make sense why AIDS hasn't evolved to become less deadly, but it also brings up that covid hasn't had a bottleneck in terms of transmission. The main reason why one strain has replaced another has been that more recent strains are more transmissible. Delta was more deadly (and transmissible) than alpha, beta & the original strain, and came later for instance. I think we got lucky with omicron, which evolved from alpha if i'm not mistaken.
- lamontcg 3y ago> Transmissible diseases usually mutate to be less deadly over time, because killing the host is a bad reproduction strategy. Incorrect. This virus has already spread by the time you're dying in the hospital and it doesn't "care" if you die or not. If it could spread more effectively during the transmissible period of the disease, while more effectively murdering you on the tail end, it'll murder you more, no problem. The Delta wave was a good example of the virus mutating to become both more transmissible and lethal, quite successfully from its perspective. The mechanism for waning virulence is that we've got T-cells which recognize conserved T-cell epitopes so the human race has some level of relatively permanent immunity now against the novel virus, and because immunity to neutralizing antibodies causes the virus to mutate and it is always competing with the immunity to its past self and that has a cost.