So this is an interesting thread, but there is nothing new here that adds any further evidence
1: they sequenced a bunch of bat CoVs from the cave by taking bat shit or anal swabs - probably into RNA later. these sequences should be published but, seems they were partial.
They used the WIV1 backbone to do the experiments that they published in PLOS which in pains me to reiterate CANNOT be the source of SARS2 itself
And lastly analyzed blood samples of the miners for antibodies to CoVs.
Which if my reading of the graph is correct all bobble around an OD of 1 except the PC which I would hazard is Positive Control (ie serum from a SARS1 recovered). Now we can debate where the negative is, but that graph doesn’t show me an conclusive evidence of CoV infection.
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The data PHE released yesterday alongside other data suggesting B.1.617.2 is outcompeting other variants in India makes a good case for this virus having enhanced transmissibility compared to B.1.1.7.
No evidence yet of enhanced pathogenesis either, but these data will take longer to accumulate.
This may well be in part due to changes in spike, BUT, as for B.1.1.7, it is not yet clear if variations in other parts of the genome play a role in relative transmission differences. And I doubt immune-evasion explains transmissibility
With is manuscript from @PaulBieniasz and co, that from @RealMcCoyLab this AM, data from @10queues yesterday and the prelim data from South Africa,
Thus far it’s a mixed bag about how much they are resistant to serum from wave 1, and vaccinee serum while slightly reduced in potency, still works. (Good news!)
But these mutations, partic 501Y (Uk, Sa and Brazil) and 484K (SA and Brazil) do completely abolish the activity of some specific individual RBD antibodies.
More alarmingly the SA variant is insensitive to about half of wave 1 sera tested.
I am becoming deeply troubled over the cavalier way the UK vaccine roll out is being changed on the hoof.
We have 2 approved vaccines that work to induce protective immunity.
They are both safe
I understand the haste to get them into as many people as possible.
But the phase iii data doesn’t exist to support their use in combination.
They are not quite the same immunogen. So homologous and heterologous boosting may accentuate different responses. And it might matter which order.
We do not know anything about this.
Next the timing
AZ boosting at 3 months turns out to boost higher Ab levels - another ‘serendipitous’ thing to fall out of the trial. Fine. But how protective is one shot?
And changing the Pfizer regimen, based reanalyzing the data to look for an answer they want. Probably true
We need a good hard look at the numbers and the longevity before we conclude that this is less effective than the mRNA based ones. bbc.co.uk/news/health-55…
Firstly it seems to rise to 90% when the first priming dose is lower. This might mean that less is more, and potentially anti-adeno responses might limit the boost. If so this is serendipitous as it will halve the cost of production of round 1
Secondly, in this trial they have evidence of reduced assymptomatic infection in vaccinees, suggestive of less transmission. This is something that we don’t know for the other vaccines thus far.
There a lot of scientists in reflective mood as we face up the prospect of an autumn second wave of SARS CoV2 and what it may or may not mean, and in particular whether we can or even should contemplate further lockdowns. So I’ll add my twopenneth’ 1/n
At the beginning we didn’t heed the warnings from China and Italy until it was too late and we ended up playing catch up with a rapidly spreading virus that we didn’t understand. 2/n
The ability to test samples and act on that knowledge was rapidly outstripped by resources and the govt were woefully slow to alleviate bottlenecks in testing, diagnostics and PPE, all of which had been highlighted when wargaming a pandemic 2 years earlier. 3/n
So hysteria helps noone. The point of flattening the curve is you mitigate the impact of SARS-CoV2 but minimize the the long term damage to the country. The way we get on top of this is by aggressive community testing and isolating infected people. 1/n
@PHE_uk job will made much easier if everyone follows the instructions: wash your hands, stay home and avoid visiting vulnerable people if you’re feeling ill. 2/n
More specific measures (eg sportscevents gatherings etc) should be brought in, but a Chinese style lockdown is not possible in a Western democracy. And ask yourself - what did Italy’s implementation of local lockdowns achieve? Very little it seems. 3/n