Hacker News Reader

Comment by throwitaway1235 | Hacker News Reader

Does anyone know if their is a correlation between how contagious a variant is and how lethal it is?

For example, MERS has a 35% CFR but wasn't a global health disaster because it wasn't highly contagious. Same goes for Ebola, which is even more fatal but even less contagious.

My point/question - the more contagious a Covid-19 variant = lower CFR?

View on HN

It is possible and even likely IMO (at least for respiratory viruses). Look up the “transmission-virulence tradeoff hypothesis” for more info:

https://pubmed.ncbi.nlm.nih.gov/30734920/

The “Russian flu” in 1890 may have been the first introduction of the common cold coronavirus OC43:

https://en.m.wikipedia.org/wiki/1889–1890_pandemic

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544107/

Also, keep in mind that stress and fear can be very bad for health:

https://www.tandfonline.com/doi/abs/10.1080/09540261.2017.13...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447278/

The virus spreads fast long before symptoms appear, so the severity of disease is not necessarily correlated.

IIRC pathogenicity has an inverse relationship with virulence.

There are no hard rules here. The UK variant is supposedly both more severe and more infectious ( https://www.bmj.com/content/372/bmj.n579 ). The common wisdom there is that something that kills you faster has less chance to transmit but there's nothing precluding something that kills you slowly and is very infectious while it does that.

Yes, Ebola is quite contageous but kills so fast it tends to burn out and not spread.

AIDS kills you slowly and is infectious while it does that, so it spreads widely.

Both are blood-to-blood, rather than respiratory. They are not at all contagious, compared to flus and colds. A lot more deadly, but they can be stopped much more easily.

Ebola spread is not stopped so much by it’s deadliness, but by the fact that you can’t get it by just being near someone who has it and is breathing.

Reply on news.ycombinator.com