How much protection do YOU think the vaccine (AZ) gives you?

[Gerla]

Just that really! And when does it start working?

Everyone the do another study it seems to get a little higher. What information do you have to hand op, when was it published and what vaccine schedule did they adopt to come to that 60% conclusion?

Everyone they...

Everytime

People are always surprised that the annual flu vaccine falls at somewhere between 40 and 60%.

The data initially published was based on clinical trials, and now the data evolves all the time. Pharma companies cannot inflate their percentages or change them weekly on the piece of paper that you received. To complicate matter, some of the data is calculated differently by different organisations. THe timing is improtant - some organisations calculate infection rate 28 days after the second dose is administered, some after 7 days. Those that show data taken after 28 days show a higher rate of efficacy.

It's really not simple. app.box.com/s/uwwn2dv4o2d0ena726gf4403f3p2acnu

@Magnificentmug12

I rekon 65% second dose 80%. I haven’t looked anything up so guessing as that’s just what I ‘feel’

I've just looked it up and that's about right. 59% after first dose (59% protected "from contracting symptomatic Covid") and 82% once the second dose has been administered.

My parents were told three weeks after first they'd have'd have protection. Different part of the country and IL weren't told that and seemed surpised it would take that long.

I thought is was around 60% after first jab- which is better than the seasonal flu vaccine some years and it would offer more protection from being seriously ill.

They're still being sensible masks, handwashing/gel limted mixing though they are possible doing a few more supermarket trips than previously. Family member who had it for work reasons still have restrictions to follow.

@notrub Thanks - obviously thinking about it, it doesn't make sense to think they mean protection against contracting the virus at all - maybe protection from serious illness resulting from contracting the virus?

@Bordois I don't have a link, I'm afraid. It was just on a piece of paper I was given re: the vaccination and possible side effects - it's in Italian.

People are always surprised that the annual flu vaccine falls at somewhere between 40 and 60%.

Yes, I am one of the surprised people! Although seeing as I have twice caught flu after having the vaccine, I guess I shouldn't be!

What people think is irrelevant. It is what the scientific data tells you that is important.

maybe protection from serious illness resulting from contracting the virus?

No, that's much higher. The study in Scotland, which was with an elderly cohort who usually produce a less robust immune response, had hospitalisations down by (I want to say 85% - it was something like that) with one single dose.

www.bmj.com/content/372/bmj.n523?cf_chl_jschl_tk=9ee2c3ad03d33e7297ba1ff68c40a76d6f9fff1f-1616590880-0-AVi-4dMTvVkQTJKff4OjHT_R5S0ZB3D7mX-qjHAqIevHrs3UoVprHoc2qhlDgB5nK8pEiuOyWkRsnqPDYSLDXn6FdZ0i-QHmWZdzPMV4x1MsuSbw-w8jyaJl3zL1mTpQN2FFcu1QBxDXxby2FJrRFioHIfJS1OVdygC1t-GUhiiTQiUZXGjARqkHUxxkxLqu7evgR3MPAJjmjb6EXegNkHSSHtLNDOovXdJkSVS68FMcTLjrsqdMJe4L67Ba5dcmFlXFloiOy9MihMlfN1n-UIrm025maRWXdbFO80JbS3sHMC4QvjGV1rpz7N6DcGVzCe7dSWHM4eWpUUEz_AhT7LBaDHGN5o557sSA4oh7fdfg

59.5% protection after two doses

against catching the virus
against getting seriously ill and dying?

what is the protection against?

What people think is irrelevant. It is what the scientific data tells you that is important.

I'd agree unless it influences how people behave which could have wider implications but you'd assume people are told or read the leaftets given.

My parents waited for four weeks before heading in person to the supermarket - having been told they need to wait three weeks to get fully protection from first jab.

The answer, on an individual level, is no one can predict that exactly.

Vaccine efficacy is a measure of the difference between the outcomes for the vaccinated and unvaccinated groups in a clinical trial. Vaccine efficiency is the same but using data from the population as a whole once a vaccine is in use.

90% efficacy/efficiency doesn't mean that the severity of disease is reduced by 90% in every individual or that person is 90% "protected", it is referring to the reduction of deaths/hospitalisations in the group of vaccinated people compared to unvaccinated. Like an average IYSWIM?

The response to the vaccine will be different for everyone.

Here you go:

www.bmj.com/content/372/bmj.n326

"A single standard dose of vaccine provided 76% protection overall against symptomatic covid-19 in the first 90 days after vaccination with protection not falling in this time frame. It is not clear, however, how long protection might last with a single dose as there were too few cases after 90 days to make any meaningful judgment.

The analyses suggest that it is the dosing interval and not the dosing level which has the greatest impact on the efficacy of the vaccine. This is in line with previous research supporting greater efficacy with longer intervals with other vaccines such as influenza and Ebola.

The study found vaccine efficacy reached 82.4% after a second dose in those with a dosing interval of 12 weeks or more (95% confidence interval 62.7% to 91.7%). If the two doses were given less than six weeks apart the efficacy was only 54.9% (CI 32.7% to 69.7%)."

@Gerla

That's not my point. I want to know what people think the answer is without googling. I'm interested in what the general perception is. If you don't want to answer, don't - but you can refrain from the snippy comments too, thanks.

'general perception"??

Lazy Journo alert.

I had it a month ago and while I haven’t changed my behaviour I feel a bit more reassured now that if I get it I shouldn’t be seriously ill.

[quote Gerla]@notrub Thanks - obviously thinking about it, it doesn't make sense to think they mean protection against contracting the virus at all - maybe protection from serious illness resulting from contracting the virus?

@Bordois I don't have a link, I'm afraid. It was just on a piece of paper I was given re: the vaccination and possible side effects - it's in Italian.[/quote]
The headline figure is normally against contracting symptomatic disease.
They take 1000 (e.g.) people who were vaccinated and compare against 1000 similar people who weren't.
If 100 unvaccinated get symptomatic disease and only 20 vaccinated, then the vaccine is 80% effective at preventing symptomatic disease.

%'s will be different if you measure different things - e.g. when it comes to serious illness, the AZ and Pfizer vaccines show a 50% reduction for those showing symptomatic disease
So using the above (example) figures - let's say that 10% of those infected get seriously ill (unvaccinated) - that would equate to 10 per 1000. But the protection for the vaccinated is double, so only 5% of the 20 get seriously ill - that's 1/1000.

Hence the protection against serious illness is now 90% - 10 per 1000 vs 1 per 1000

NB these figures are just example numbers, picked to make the maths easier - for actual protection levels see official data associated with each vaccine.

Protection against transmission is another measure, although that's much harder to quantify and they can only guesstimate based on changes in overall infection levels. We know it's quite high (with current variants in circulation).

I don’t know.

If I had had Pfizer, antibody response was found in 8-13% of recipients at 3-5 weeks after their jab. I’ve yet to see results for AZ, but although different jabs they both target the spike protein, so I expect it’ll be similar

I have blood cancer, which is the group with poorest response. Those living with other cancers had response rate of 39-43%, and those with no cancer 97-100%

Yes still the government hasn’t restored group 6 priority to immediate households if the CEV (included in the first draft JCVI priority list, but suspended pending more evidence on effects on transmission, still waiting)

Not read the other replies, but from 22 days after the first AZ dose there were no severe cases of covid or hospitalisations in the trials, which is excellent.

@Geamhradh

People are always surprised that the annual flu vaccine falls at somewhere between 40 and 60%.

Same as the TB vaccine I believe. We have the technology to try and improve this but there’s no appetite for it because generally it’s enough.

If a journo is reading I would like to see an article detailing the efficacy of well known vaccines so there is more perspective on the corona virus vaccines. I’d compile it myself but I don’t get paid to sit and do it

I'm not a doctor or a scientist so "what I think" about vaccine efficiency is totally irrelevant. Nor am I interested in the witterings of uninformed people.

I accept the published advice of accredited research scientists and doctors. I recognise that as they do more research on more patients, their expert knowledge and advice may change.

Many studies that have now completed showing the 70%+ protection that wouldn't have been in when the leaflets were written remember - they have to err on the side of caution initially.

I'd have been happy with 59% tbh - that 59% more protection than the 0% of covid antibodies I had before I walked in for the jab.

And also remember that even if you still catch it, you're going to have a much milder dose due to having existing immunity from the vaccine.

I think all these percentages are pretty meanigless really as it all varies individually anyway. Its a case of having "lots" of protection post vaccination versus "none" before (unless you've had covid maybe but most people are trying to avoid that due to long covid effects)

@Geamhradh

People are always surprised that the annual flu vaccine falls at somewhere between 40 and 60%.

There's a number of issues with flu vaccines that so far we haven't faced with covid.

One of them is that when vaccinated) if a person has previous exposure to a different mutation of the virus, their immune system may choose to prefer the existing defenses it has, over one essential to combating the new mutation.

I found a really good article the other day explaining this with a car analogy, but today I can't find it to link :(

It went along the lines of - suppose the virus is like a car - the first encounter, your immune system targets the wheels, the hood ornament and the exhaust pipe. Only the attack on the wheels has any impact on the car, but your immune system doesn't know that. It only knows it beat it.

So then the virus changes just the wheels. You get a booster designed to introduce your immune system to the new wheels, but your immune system still has two targets it knows about - it may decide to stick with the two it thinks work, rather than incorporate the new wheel target. So then when infected, your immune system spends a while uselessly attacking the hood ornament and exhaust pipe before recognising it isn't working and looking for a new target - in essence you're as exposed as if you were unvaccinated.

With flu this may play a part as there have been so many mutations of influenza over the years.

With covid, we won't have that issue yet, indeed it may never arise, depending on how the virus mutates in the future.