COVID Vaccine !

[Craig the cyclist]

Can you clarify what you think the difference is? Cheers.

Most obviously, the parameters you are quoting. The study you referenced doesn't mention death, but you do, after telling us to 'Read carefully'

efficacy is normally quoted against all symptomatic disease.

What does that even mean? If I knew what it meant I would respond

 

[roubaixtuesday]

you do, after telling us to 'Read carefully'

I'm very happy to be corrected when mistaken. I don't *think* I am here, as severe disease I think includes fatal disease, but I've not read the precise definition in the trial. The "read carefully" was that the 85% quoted is not the measure commonly quoted:

What does that even mean?

Efficacy primary endpoint in all the trials I've read is reduction in symptomatic disease, regardless of severity of the disease.

Reduction in severity is not normally the primary endpoint or quoted as headline figure.

Neither is asymptomatic disease as detected by PCR (not all trials test asymptomatic subjects).

Does that clarify?

 

[Craig the cyclist]

I'm very happy to be corrected when mistaken. I don't *think* I am here, as severe disease I think includes fatal disease, but I've not read the precise definition in the trial. The "read carefully" was that the 85% quoted is not the measure commonly quoted:



Efficacy primary endpoint in all the trials I've read is reduction in symptomatic disease, regardless of severity of the disease.

Reduction in severity is not normally the primary endpoint or quoted as headline figure.

Neither is asymptomatic disease as detected by PCR (not all trials test asymptomatic subjects).

Does that clarify?

Thank you, it clarifies, but isn't quite correct. The main quoted figure is actually efficacy of preventing the disease being caught, not reduction in severity of the disease.

Lots of the studies are also looking at transmission rates, asymptomatic disease treatment, asymptomatic disease transmission, efficacy of one or two doses, efficacy in different groups etc.

A vaccine isn't a treatment as such, it is actually a prophylactic. There is little point giving one to a sick person with the disease.

 

[roubaixtuesday]

The main quoted figure is actually efficacy of preventing the disease being caught, not reduction in severity of the disease.

I don't think it is efficacy against COVID being caught.

I think the 85% is reduction is of *severe* disease reported.

Headline figure normally quoted is reduction of *all symptomatic* disease.

All studies I've seen show a much larger reduction in severe disease than mild disease. So the 85% overstates the efficacy of this vaccine against the variant, relative to how efficacy is normally quoted. Again, that's not to criticise the vaccine or the study, just to caution that it doesn't mean this vaccine is better than others where lower efficacy has been reported against the variant - it's not the same measure of efficacy.

[Caveat: I've not read the paper, just the report. I may be wrong!]

A vaccine isn't a treatment as such, it is actually a prophylactic

Agreed.

 

[Buck]

Direction is for Local Vaccine Centres/GPS not to use Pfizer for first doses as guarantee of supply is not there. Any Pfizer to be used for second doses only.

Currently we‘ve only got AZ for first vaccines although supply does seem to be increasing (slightly).

 

[Ajax Bay]

Interesting quote you have written there. The study you quoted doesn't actually say that. It says this........
"One dose was 85% protective against the most severe Covid-19 illness, in a massive study that spanned three continents — protection that remained strong even in countries such as South Africa, where the variants of most concern are spreading."

Craig - after rt's 'heads-up' I commented in a little more detail drawing not on the news report shared by rt but from the J&J Announcement of Clinical Trial (RCT) Results (29 Jan) . Did I get it right? Here's the (US) NIH report of the Jansen RCT which had "combined endpoints of (1) moderate and (2) severe disease".
I'll share the criteria of illness against which the Pfizer and Oxford-AZ trials reported their efficacy in another post.
J&J-Jansen: "Vaccine was 66% effective overall in preventing moderate# to severe COVID-19, 28 days post-vaccination, with varying levels found: 72% in the United States, 66% in Latin America and 57% in South Africa (mostly against B.1.351 variant in SA). The vaccine was 85% effective in preventing severe disease* across all regions"
People have to suffer severe illness before death (assumed) so there's 85% efficacy against the latter (too). I included the definitions that J&J gave for 'moderate' and 'severe' COVID-19 in my post #2768 ^^.

I'm very happy to be corrected when mistaken. I don't *think* I am here, as severe disease I think includes fatal disease, but I've not read the precise definition in the trial. The "read carefully" was that the 85% quoted is not the measure commonly quoted:
Efficacy primary endpoint in all the trials I've read is reduction in symptomatic disease, regardless of severity of the disease.
Reduction in severity is not normally the primary endpoint or quoted as headline figure.

I do not think you are mistaken but I shall look at this 'next'. Maybe the 85% is being used for communications purposes to minimise hesitancy. Look at Germany's hesitancy with Oxford-AZ after the tragic 'only 8% efficacy' claim by newspapers which was weakly refuted by its Federal MoH, followed by an unwillingness by BfArM to licence its use for over 65s (still in place).

 

[postman]

Thirteen million people could not be aresenaled to vote in the referendum.I wonder how many people are going to refuse the jab,saying covid is a fake.How will the Gov react to that and what about treating them if they end up catching it.Is there anyone on here who is not having the jab and why.

 

[Ajax Bay]

Deepo breath @classic33 . Skippy has shared his reasons already, @postman. Just put a bit of effort in and scroll back a few pages and read. Are you here for a chat or an argument postie? Why don't you list the reasons for refusal you'd find acceptable? And 'yes' if someone falls ill with COVID-19, the NHS will 'treat them'. Do you think that's right?
Bear in mind that of those who would have caught it if there'd been no vaccination, one in ten who have been vaccinated will still, as you put it, "end up catching it". The vaccine is not 100% effective - but looks like both Pfizer and Oxford-AZ are >80% effective after one dose, for a time period uncertain.

 

[classic33]

Thirteen million people could not be aresenaled to vote in the referendum.I wonder how many people are going to refuse the jab,saying covid is a fake.How will the Gov react to that and what about treating them if they end up catching it.Is there anyone on here who is not having the jab and why.

Me, on medical grounds. Not my choice, manufacturer's recommendation.
I'd not want the person who gave the injection being held responsible.

And I'm not reading anything into your question, before anyone has a go at you for asking a reasonable question.

 

[Ajax Bay]

From the 'Germany hesitancy' thread

My understanding is that clinical trials of this type consciously exclude older people - for the simple reason that they are more vulnerable and, by definition, a clinical trial exposes all participants to a degree of risk.
BUT there is no medical reason to suppose that an immune system response would cut off at the upper age of the trial participants, and therefore no reason to exclude older folk from vaccine rollout.

The emboldened bit: I think they actually don't (but agree with all the rest of what you said). In fact the lack of efficacy data for the Oxford-AZ vaccine for over 65s from that trial is as a result of that trial not having sufficient O/65s (and a small percentage of O/55s). And then not many of the control group of the O/55 cohort catching C19, to compare with none in the vaccinated O/55 group.

The Oxford-AZ RCT report has this on participation (edited):
"Only 1418 (12·1%) of those assessed for efficacy were older than 55 years . . [cf Pfizer trial participation, below] . . meaning that from the interim analysis of these trials, we cannot yet infer efficacy in older adults, who are the group at greatest risk of severe COVID-19 outcomes.
"less than 4% of participants were older than 70 years of age,"
Just shows you have to be super careful about putting a trial together, and a lesson identified from this has to be that if the disease you're trying to test a candidate vaccine attacks older people (or black/BAME or men or ) then it's wise to structure trial participants accordingly, including ones with relevant morbidities.

The Pfizer RCT report has this on participation (edited):
"43,548 persons 16 years of age or older started, and a total of 37,706 participants finished (various drop out reasons). Among these 37,706 participants, 49% were female, 83% were White, 9% were Black or African American, 28% were Hispanic or Latinx, 35% were obese (body mass index [the weight in kilograms divided by the square of the height in meters] of at least 30.0), and 21% had at least one coexisting condition. The median age was 52 years, and 42% of participants were older than 55 years of age." Plenty of oldies (ish) and 16s and 17s in the trial.

 

[postman]

No no arguments God forbid.I am of the opinion that covid is going to get a bashing from the vaccine and apart from medical reasons I can't see why anyone would refuse to have it.I would like to see stronger travel restrictions on people coming in from other countries who are not as up to date as we are.And I think that should have been done earlier.I hope by this summer people with doubts will see a difference and believe in the vaccine.

 

[lazybloke]

No no arguments God forbid.I am of the opinion that covid is going to get a bashing from the vaccine and apart from medical reasons I can't see why anyone would refuse to have it.I would like to see stronger travel restrictions on people coming in from other countries who are not as up to date as we are.And I think that should have been done earlier.I hope by this summer people with doubts will see a difference and believe in the vaccine.

Vaccine reluctance is one thing.
Testing reluctance - ie the withholding parental consent to testing of school children - is a whole new world of stupidity.

I accept that some people need an opt out. The majority do NOT.

 

[lane]

So going back to the 85%. Someone in my age group has something like 8.5% chance of ending up in hospital if they catch it - so severe - on average. So 85% effective reduced the 8.5% to 15% X 8.5% = 1.2% which is reasonably low.

What I don't quite get is - does someone have a much lower chance of catching it AND if they do they have a much lower chance of it being serious or is that double counting somehow?

 

[classic33]

Vaccine reluctance is one thing.
Testing reluctance - ie the withholding parental consent to testing of school children - is a whole new world of stupidity.

I accept that some people need an opt out. The majority do NOT.

"Not recommended", from the manufacturer, isn't an opt out.

 

[Ajax Bay]

England vaccine performance in over 80s (source not available):

Londinium at 82% bringing up the rear. The eager south west over 80s @ >98%!