NSW and Vic show excellent evidence that vaccine effectiveness against onward transmission is high (>86%)!
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I fit the R_eff vs vaccination data for NSW and Vic to a linear relationship, to get two parameters, the R_eff at zero vax, and the vax effectiveness against onward transmission (VET). The result:
NSW: R_eff(0 vax) = 1.65; VET = 86.1%
Vic: R_eff(0 vax) = 2.27; VET = 86.4%
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Solid lines are the Doherty model, linearized:
Doherty uses a transmission matrix which effectively weights some ages more than others in relevance to transmission. I assume vax affects everyone equally. I take a weighted average of VET = 89.7% for AZ (86%) and Pfizer (93%).
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Best fits indicate VET is ~86% (close to Doherty 86-93%). NSW and Vic agree very well.
Vic tracks consistently higher than NSW. This is roughly consistent with the difference between Doherty "high" and "medium" PHSM.
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We don't know why there is a difference (intrinsic to Syd & Melb? Weather? Lockdown fatigue?)
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Conclusions:
1) NSW and Vic data both consistent with a high (86%) vaccine effectiveness against onward transmission in the simplest model.
2) Doherty Inst model was very well calibrated for NSW.
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Conclusions cont'd:
3) VIC shows consistently higher R_eff compared to NSW. Vic would be justified in taking a more cautious approach to re-opening. If high R_eff due to "fatigue" then may be OK. If intrinsic to Melb, more restrictions needed after opening.
7//7
Addendum:
VET here is the *overall* vax effectiveness against transmission! (Not "onward")
If vaccine has X eff against infection, Y eff against (onward) transmission if infected, then overall VET = 1-(1-X)(1-Y).
Top-level result here is that covid is 1.35 times [95% CI, 1.10-1.66] more deadly than influenza in this cohort (VA patients hospitalized due to covid or influenza).
Around 44% of those hospitalized for influenza had been vaccinated this season. While that's lower than the average vaccination for this age cohort (most >65) of around 54% (quite possibly because the vaccine works!)
But...
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...it's a lot higher than the fraction of >65s vaccinated for covid in the past season (29%).
So, in a group that's almost twice as likely to have been vaccinated for influenza than covid, covid is 35% deadlier. Not exactly earth-shattering.
The new study used TriNetX, a research network allowing access to electronic health records. Most of the cohort was from the US, but should represent a broader range of the population, on average younger and healthier than VA.
They found that, for those with a covid diagnosis, the risk of a subsequent neurologic diagnosis was statistically significantly higher (on average 40% higher) for every disorder studied.
Flu and RSV hospitalizations have peaked in the US. How does this season compare to previous?
Thread.
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RSV first. Overall, RSV hospitalizations are down a little this year compared to last but still higher than pre-pandemic.
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Age stratification is interesting. The peak in RSV hospitalizations in kids (<18y, blue) is still higher than pre-pandemic years but less than half of last year's whopping mega-peak.
In testimony before the US Senate yesterday, Dr. Ziyad Al-Aly (@zalaly) is quoted as saying “The burden of disease and disability in Long Covid is on par with heart disease and cancer”.
I’d like to revisit this study by @zalaly’s group.
I want to tackle one issue in particular:
Does the study provide evidence that those hospitalized for COVID-19 had worse *long-term* health outcomes compared to those hospitalized for influenza?