NEW: we know cases rising fast in South Africa, but what about severe outcomes?
I spent yesterday pulling together hospitalisations for Gauteng province, so we can compare the fledging Omicron wave to those that preceded it.
So far admissions following ~same path as past waves.
Quick notes (1/2):
• For cases to be rising faster while admissions are on same pace may hint at a lower proportion of severe disease
• But this may also simply be the result of more infection-acquired immunity and vax
• Or of cases so far being predominantly younger people
And 2/2:
• Share of patients in ICU currently much lower than same stage of Delta wave, but may change if cases spread from being mainly young. Or may not, which would suggest T and B cells kicking in 🤞
• Please follow people on the ground incl @Tuliodna@tomtom_m@rjlessells
Couple more footnotes:
• I have the data on patient numbers too, though it's messier because the number of hospitals that report data can change from day to day. So far it shows broadly similar pattern to admissions — I'll share this shortly when I've cleaned it a bit more
• Enormous credit to the team at @nicd_sa who painstakingly gather this data every day. As with the discovery of Omicron, we owe everything we know on this to the in-country teams
• • •
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Caveat first: data here is *very* preliminary, so everything could change. Nonetheless, better safe than sorry.
1) Based on the data we have, this variant is out-competing others *far* faster than Beta and even Delta did 🚩🚩
2) This is coinciding with a wider rise in cases in South Africa.
Again, currently we’re talking about small numbers (both of B.1.1.529 and of cases in SA overall), but there’s a clear upward trend. This may be a blip, but this is how waves start.
3) Aside from its rapid rise in South Africa, the other key reason for concern here is that the specific mutations that B.1.1.529 has are — based on what we’ve seen with other variants — known to be associated with greater transmissibility & immune evasion
The situation is even clearer when plotted on a log scale:
UK is broadly a flat line, with European countries cutting up steeply through it. France, Italy & Spain all on course to pass UK for cases. Germany now above UK for daily deaths and Netherlands set to follow.
So why these exponential surges across Europe but not in the UK?
There’s increasingly little difference in social mixing behaviour between the countries, and where we do see differences e.g in mask-wearing, they’re generally more virus-friendly in the UK 🤔
The good thing about this story is that any time I see someone sharing it as evidence that wearing masks cuts Covid incidence by 53%, I know they haven’t read the paper it’s based on and aren’t fussed about the quality of evidence as long as it produces the right number 🙃
What do I mean by this?
Let’s start by saying that yes, we have good evidence that masks reduce Covid incidence 😷🦠📉😀
BUT it points to nowhere near a 53% reduction. As today’s @bmj_latest states, the best evidence — randomised controlled trials — point to more like a 10% cut
Indeed, here is the BMJ’s take on today’s paper:
• Most of the studies included in the meta-analysis from the Guardian story are poor quality and subject to major biases
• We need more & better research [like the mask-wearing RCTs which have consistently found a smaller effect]
NEW: @UKHSA study finds Pfizer booster is extremely effective against symptomatic infection, both compared to the unvaccinated and to those with 2 doses ft.com/content/8330da…
Whether first 2 doses were AZ or Pfizer, a Pfizer booster sends vaccine efficacy up to 93-94% 💪
Study was on people aged 50+, comparing those boosted ~5+ months after dose 2, to those @ 5+ months unboosted.
AZ efficacy was 61% after dose 2, waning to 44% @ 5 months.
Pfizer was 82% after dose 2, waning to 63% @ 5 months.
2 wks after Pfizer booster, both groups -> 93-94%!
Best way to think about booster impact is not to look at going from 44 to 93 with AZ, i.e roughly doubling, but invert the numbers and go from (100-44) to (100-93), i.e from relative risk vs unvaxxed of 56% to just 7%
That’s an 87% increase in protection *relative to two doses!*
NEW: England has recorded 18 successive days of week-on-week declines in cases, its longest sequence of declines since February, suggesting its autumn/winter wave may have peaked ft.com/content/e11add…
Crucially, hospital admissions, patient numbers and deaths are now also trending downwards, as the fall in case numbers has shifted from being youth-driven into all age groups.
These acute indicators look to be topping out at 10-20% of last winter’s peak levels.
A key factor here has been England’s booster rollout.
Antibody levels in the oldest groups (vaccinated the earliest) had been slowly eroding as the months passed, but in the last 5 weeks they have shot back up as third doses have gone into arms 💉💉💉💪💪💪