Thread by @WanOvi

🚀📈Delta viral load is not x1000, explained

In my opinion this study is not being interpreted wright

virological.org/t/viral-infect…
@Guillermo4ldama @EricTopol @gorka_orive @PabloFuente

The study claims:

👉The investigation on daily sequential PCR testing of the quarantined subjects indicated the viral load of the first positive test of Delta infections was ~1000 times higher than that of the 19A/19B strains infections back in the initial epidemic wave of 2020

It does not say that viral load is x1000, just says that when first detected it is x1000

They do PCR every 24h. In the 24h gap between a negative test and a positive one, delta grows much faster, resulting in higher virus count at that particular time

Unfortunately the report of this study lacks of clear explanation of this graphic, would be great to have the raw data to define this precisely

One important conclusion is that the delay (less than 24h) between AG detection versus PCR is much less now with delta

Also this justify to ask for PCR 24h instead of 72h, and reduces the time a negative result gives you a low % of turning into +

The study gives valuable info:
Shorter pre-detectable/incubation period
Much faster grow in early stages
Very contagious in pre-synthomatic

But is a shame the didn't carry on with 24h test once every case is first detected, writing down the CT value for every test

This way we could build an accurate viral load curve, which is of vital importance

"There's a 40% drop in vaccinated viral load, which is not much. Still plenty of virus to transmit to others, and Delta makes up for it by reaching 2-4x higher levels than previous variants"@michaelzlin
researchsquare.com/article/rs-637…

This graphic is for the original type. With #deltavariant the rise is even more vertical,this explains x1000 in early stages

same graphic👇 log10 scale

Time lapse between detection and infection is being reduced a lot, in both Rapid antigen LFT and PCR, if the study is wright

Schematic: Time lapse between detection and infection for AG, original vs delta

Even more reduction for PCR

Schematic: Time lapse between detection and infection for PCR, original vs delta

The day when virusses were first detected, delta was x1000 (Ct24 / ct34)

From assets.publishing.service.gov.uk/government/upl…
Difference between original (EU1) and delta is around 2 ct at peak (1-2 day after synthoms) meaning x4 viral load, and after 1 ct ~x2
In my view, x1000 is only at the moment virus is detected doing PCR every 24h,

variants in uk form covariants.org