Coronavirus Sars-CoV-2/Covid-19 Megathread

[crazy canuck]

I predict that within a few months we will figure out that it would have been better to vaccinate all children as well immediately.

And that it was a terrible mistake to reduce all the other protections we had in place before high percentages of full vaccination were attained.

I think it likely that masking indoors is going to become mandatory again.  BC infections went up this week - just a bit but it is all down to the variant and the fact double dosed people can still be infected and spread the infection.

[Zanza]

I predict that within a few months we will figure out that it would have been better to vaccinate all children as well immediately.

And that it was a terrible mistake to reduce all the other protections we had in place before high percentages of full vaccination were attained.

Yes.

[Sheilbh]

Slightly worrying data issued by the Israeli Ministry of Health that immunity for the early vaccine cohorts is waning - this shows cases among the groups vaccinated before the end of January:


Infections and hospitalisations among the early vaccinated are rising at 3-4 times the rate of people vaccinated after May. I understand this holds once you adjusted for testing (people who got vaccinated are more likely to get tested than the unvaccinated).

Israel mainly has the delta variant and interestingly their MoH data had previously shown lower effectiveness in vaccines against delta than similar data from the UK public health authorities (UK data is broken down by vaccine). This is still internal positions papers rather than full research but apparently the MoH are certain that waning effectiveness is part of the issue - and I wonder if that is why it looked like the vaccines were less effective against delta. They're not, it's just that Israel was early and quick on vaccinations so is noticing waning effectiveness first.

[viper37]

Which vaccine(s) did Israel mostly deployed first?

[Sheilbh]

I think Israel only uses Pfizer, I know they did to begin with but they might have used others later on - not sure.

[jimmy olsen]

The R0 of the Delta variant is between 5 and 8 according to the Imperial College

https://www.google.com/amp/s/www.bbc.com/news/health-57431420.amp

[Legbiter]

I think the experiment was worth doing to get the vast majority vaccinated and then relaxing border restrictions on vaccinated travelers.  There will be further control measures implemented here domestically and on the border. We now have more than a hundred confirmed new cases, all linked to a single Reykjavík night club and another cluster linked with a weekend trip to London. The tourism industry here can't whine too loudly because the megaboom in incoming travelers was in large part because of our outstanding success in eradicating the bug domestically. Over a hundred new cases in 3 days will put us deep in the red, hence many tourists will cancel because of quarantine requirements when returning to their home countries.

[Legbiter]

Also, and this is interesting a large majority of vaccinated people here being infected with the delta variety all had the single-dose Janssen vaccine. It's basically worse than useless, because of the false sense of security it gives, so everyone who's had it will be offered a mRNA booster dose starting next week.

[Tamas]

So how does the finding of falling antibodies after vaccines align with the earlier bone marrow tests of previously infected people showing "prints" of antibodies 6 months after infection? If you have an antibody "blueprint" in your bone marrow memory does it get produced constantly (i.e. antibodies will be identifiable in the blood) or production of them stops after a period of time, but can be restarted by the body if a fresh infection starts?

[DGuller]

I wish the reports of breakthrough infections differentiated between vaccines.

[Barrister]

So how does the finding of falling antibodies after vaccines align with the earlier bone marrow tests of previously infected people showing "prints" of antibodies 6 months after infection? If you have an antibody "blueprint" in your bone marrow memory does it get produced constantly (i.e. antibodies will be identifiable in the blood) or production of them stops after a period of time, but can be restarted by the body if a fresh infection starts?

My understanding is that it is normal for antibodies to decline and even disappear post-infection.

Your immune system "remembers" the various infections you've fought off using your B-cells and T-cells, and if the virus is spotted again your body will again produce antibodies to fight off the virus.

It is however much easier to detect antibodies using a simple blood test, and much more difficult to locate C and T cells that will respond to the specific virus you're interested in.

[Sheilbh]

So how does the finding of falling antibodies after vaccines align with the earlier bone marrow tests of previously infected people showing "prints" of antibodies 6 months after infection? If you have an antibody "blueprint" in your bone marrow memory does it get produced constantly (i.e. antibodies will be identifiable in the blood) or production of them stops after a period of time, but can be restarted by the body if a fresh infection starts?

I've no idea - the Israeli MoH stuff is still an internal paper of something they think is happening and is driving their infections - there's not full research about it from what I've seen. Though I imagine that will come and hopefully maybe it's just a blip and not a thing.

But what has been released is infections and hospitalisations which are both 3-4 times higher for early vaccinated v recently vaccinated so that suggests they may not be re-activating with fresh infection?

Interesting case stats in the UK - it's very early days but case numbers are starting to fall in England. Obviously this won't show the impact of Monday's re-opening yet. But it makes me wonder how much of this wave was a Euro 2020 wave, as with Scotland (where cases are falling rapidly after peaking a week after Scotland's last game in the Euros: https://public.tableau.com/app/profile/phs.covid.19/viz/COVID-19DailyDashboard_15960160643010/Overview). Schools are still open so that's probably not a factor - but also the weather's been great for the last week so I wonder if people have been outside more too which has an impact.

There will be an increase now there's been a new level of re-opening (not sure how much - in part because I suspect the people who will take advantage of new rules are already likely to be going out and mingling while people who are concerned about cases will already have changed their behaviour). But I think the Scottish numbers are the first time we've seen cases fall (from a peak of 4,000 new cases three weeks ago to under 2,000 new cases this week) without any new lockdown or restrictions being implemented - I think like England, they delayed further re-opening but didn't have any new measures. I can't think of any other examples?

Probably connected - the latest ONS antibody survey estimates that 92% of adults in the UK have antibodies (overwhelmingly from vaccines).

Edit: Basically - I still don't know. Cases look encouraging, hospitalisation trend looks worrying, impact of Monday unknown. But Scotland is very interesting and clearer.

Edit: Also - totally different - an amazing report about India's rural vaccination teams:
https://twitter.com/BBCRajiniV/status/1418132994871734273?s=20

[garbon]

Sheilbh, I wonder if this is some portion of what JCVI was looking at when we asked if they had any scientific evidence to support long delays.

https://www.theguardian.com/world/2021/jul/23/pfizer-vaccine-second-dose-has-sweet-spot-after-eight-weeks-uk-scientists-say

Pfizer vaccine second dose has 'sweet spot' after eight weeks, UK scientists say

Longer schedule led to more Covid antibodies and higher proportion of helper T-cells, supporting immune memory – researchers

Of course details we know about this currently:

• Sample: 504* NHS workers of whom 3/4 were women and 44% had already had COVID
• Not yet in print, no peer review
• Both short and long dosing intervals generated strong immune responses overall
• 3-week interval generated fewer neutralising antibodies than 10 weeks
• Antibody levels dip after first dose with longer intervals though authors say that levels of T-cells remain high so may be okay
• Longer schedule leads to fewer T-cells overall but there is a higher proportion of helper T-cells

*According to this BCMJ article I found when trying to find anyone else studying dose intervals, that's a very small sample - particularly when you figure there were 3 intervals looked at. edit: pre-print says it was 75 on short intervals vs 428 on long interval.

https://bcmj.org/articles/what-evidence-extending-sars-cov-2-covid-19-vaccine-dosing-schedule

Similarly, the trials of the Oxford-AstraZeneca vaccine did include different spacing between doses and found that a longer gap (2 to 3 months) led to a greater immune response, but the overall participant numbers were small.[6,7] In the UK study, 59% (1407 of 2377) of the participants who had two standard doses received the second dose between 9 and 12 weeks after the first. In the Brazilian study, only 18.6% (384 of 2063) received a second dose between 9 and 12 weeks after the first.

[Sheilbh]

That makes sense - and at least it feels like they have some basis for their insistence on this because it seems strange otherwise. Similarly it makes sense that they'd be looking at pre-print/emerging research from within PHE or the NHS rather than waiting for publication and peer review.

But it still feels quite small to be insisting on this in such a strict way. Especially because I would have thought it would be easy enough to do a larger study in the NHS, not least because there's lots of data and it's in one place - so I saw an American epidemiologist saying the UK is quite good at turning around studies on vaccine efectiveness that are good very quickly because there's a big dataset to work with.

And I wonder how they balance that benefit against the risk in the gap - because we know that with delta the second dose is far more important than it is with alpha.

It's a bit like I feel they should be expanding the use of AZ because when that was restricted the risk of a serious side effect outweighed the risk from covid because case numbers were very low. Now case numbers are very high, the risk from covid will outweigh the side effect risk. But they don't seem to be moving on that.

[garbon]

That makes sense - and at least it feels like they have some basis for their insistence on this because it seems strange otherwise. Similarly it makes sense that they'd be looking at pre-print/emerging research from within PHE or the NHS rather than waiting for publication and peer review.

But it still feels quite small to be insisting on this in such a strict way. Especially because I would have thought it would be easy enough to do a larger study in the NHS, not least because there's lots of data and it's in one place - so I saw an American epidemiologist saying the UK is quite good at turning around studies on vaccine efectiveness that are good very quickly because there's a big dataset to work with.

And I wonder how they balance that benefit against the risk in the gap - because we know that with delta the second dose is far more important than it is with alpha.

It's a bit like I feel they should be expanding the use of AZ because when that was restricted the risk of a serious side effect outweighed the risk from covid because case numbers were very low. Now case numbers are very high, the risk from covid will outweigh the side effect risk. But they don't seem to be moving on that.

Yes, good they were relying on something but does feel weird to be strict about it based on this.

Also not helpful, I don't think, to have every news org putting out headline that you need to have that gap...beyond say supporting JCVI guidance. I've already seen people saying though that Fauci and others need to apologise to the UK / people fretting they got their 2nd dose too soon.  News orgs seem to be doing nothing to contextualize the results of this small study.

On risk in gap, that's the flimsy bit where study authors say t-cells remain steady throughout so might be okay.