So may as well add my 2pth-worth

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
B.1.617.2 does have a reduced sensitivity to certain antibodies elicited by vaccination (like B.1.1.7), but the good news is that at the moment the data isn’t a real difference in an individual’s protection PROVIDED they’ve had both shots of vaccine.
The issue we have to deal with is with transmission in unvaccinated and partially vaccinated people. The latter are a problem because they will be a much more heterologous bunch immunologically than those who have had the booster.
And a more infectious virus might get through the defences more efficiently and be able to spread – but it doesn’t follow that it will make someone seriously ill. And B.1.617.2 is less well blocked by 1 shot
Time since shot, age etc are all going to dictate how well someone responds, and everyone should be aware that a minority of people never respond well to a vaccine. Therefore, we need to get second shots into people as soon as we can.
This is where IMO opinion, AZ is a bit of a problem. Not because it is a poor vaccine (far from it) but because optimal protection requires a 3 month gap btw shots probably because you need anti-vector immunity to wane.
Pfizer by contrast is great at 21-days to boost. We changed this regimen to 3months to protect stocks and make them go further. Many of us were worried about this at the time because of what might happen if we had spread of variants in partial vaccinees.
I would seriously consider 2 things: firstly, bringing down the gap btw doses of Pfizer and throwing it at areas of B.1.617.2 transmission
secondly, if we can and safety permits, giving people who have had AZ at least a month ago a boost of Pfizer instead
Lastly, we can’t vaccinate our way out of an epidemic without suppressing transmission, and if that means revising the speed of some of the easing of NPIs, so be it.
So in the end there is both good news and bad news in the PHE report. We need to take it seriously, but also not panic either. We have the tools to sort it.
And remember that #vaccines work, and your chances of being ill yourself after a full regimen is very low, even if you meet a new variant. So as soon as you have the opportunity, do it

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More from @stuartjdneil

20 May
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.
Read 4 tweets
20 Jan
With is manuscript from ⁦@PaulBieniasz⁩ and co, that from ⁦@RealMcCoyLab this AM⁩, data from ⁦@10queues⁩ yesterday and the prelim data from South Africa,

The variants we are seeinv have evolved to escape antibody.
biorxiv.org/content/10.110…
How and where to be determined.

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.
Read 8 tweets
1 Jan
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
Read 5 tweets
23 Nov 20
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.
Read 7 tweets
19 Sep 20
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
Read 27 tweets
11 Mar 20
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
Read 5 tweets

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