Thread by @dgurdasani1

Myth debunking:
After reading more misleading takes in the media, I'm going to try to explain this again- overall, omicron causes *more* and not less severe disease than delta - even at an individual level for most people. Why? 🧵

Your risk of getting hospitalised with SARS-CoV-2 (any variant) depends on two things?
1. how likely are you to get infected?
2. what is your chance of getting hospitalised *once infected*

In simple terms, because omicron can escape immunity from past infections and vaccines, your protection against infection against omicron is vastly lower than with delta. This means risk of 1. is vastly increased- as you're less protected & also v. high background transmission.

This risk would've been *much* lower with delta, as your chance of getting infected if vaccinated would've been much lower. You protection *once infected* (number 2. above) doesn't change much. But overall because 1. is hugely reduced, your total risk is actually higher.

All the 'mild' takes compare omicron hospitalisations *once* infected, without accounting for the fact that omicron is infected people who're vaccinated and had past infection who wouldn't have been infected with delta at all because they were protected.

So, it's increasing risk, rather than reducing it, by infection people who wouldn't have been infected with delta- which means we are actually at higher risk of severe disease - because of lower protection from infection with vaccination with omicron compared to delta.

Takes like this for example, completely miss the point:
theguardian.com/world/2021/dec…

Remember, a huge part of the omicron advantage is being able to infect people with previous immunity that delta wouldn't have been able to penetrate. To argue that this somehow leads to a reduction in risk, is frankly nuts.

So be wary of 'conditional takes' - that discuss risk of hospitalisation *once infected* because they don't account for the risk of infection which is hugely increased, and overall risk individually depends on both.

And also on takes that don't acknowledge that omicron is infecting people who wouldn't have been infected by delta- many with prior immunity so with protection from severe disease- but still be more likely to get ill overall because delta wouldn't have infected them at all.