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

[Gerla]

Just that really! And when does it start working?

@FlyingBurrito

I don't think top medical scientist are lying.

It's common knowledge that vaccines don't work for some people. Not everyone will be protected after being vaccinated.

So when they give out figures like 81% protected after 2 doses, that doesn't apply to everyone.

I've always had shit luck with modern medicine and better luck with letting my body take care of me - so I reckon the vaccine won't work on me and I'd rather take my chances with Covid.

In any case, you’re not a certain percentage protected against symptomatic infection which some people believe to be the case when they read “ % effective”.

Really interesting to learn this.

Great thread OP. It’s educated me.

@2bazookas

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.

Amen

Not a clue. I asked my consultant who said the same as I have a rare blood disorder

As PP have said, we only have the data for the population. We don't know what it is for any one individual.

Personally I have different ideas of the protection it gives according to the situation. If I'm going to be indoors around other people, eg in a shop, I behave as if the protection is lowish and get a move on with my errand, give people space, etc. without going over the top.

If I'm outside, I behave as if it's probably fairly good and generally don't take avoiding action, beyond normal polite space.

If I'm lying awake at 3am I assume I have 100% protection and tell myself I'm not going to go down with Covid and to go back to sleep.

But overall I feel that I'm safer myself and less likely to give Covid to others than I was without the vaccine although I can't put a figure on that. While I'm positive about it, I bear in mind that if I have overestimated the protection in my case I could affect others.

None! And you are all delusional if you think it will. Its an mRNA not an actual vaccine so I’m not even sure why it’s still being called a vaccine. I’ve heard a doctor mention it’s like having chemotherapy just in case you cancer [hmm

The Oxford AZ isn't a mRNA. That's Pfizer and moderna.

Starts working around 22 days after

I know noone has died of covid if they have had the AZ

Enough. Move on

@baggyjeans

None! And you are all delusional if you think it will. Its an mRNA not an actual vaccine so I’m not even sure why it’s still being called a vaccine. I’ve heard a doctor mention it’s like having chemotherapy just in case you cancer [hmm

I had the AZ which is not an rna vaccine

And in answer to the question I hope its around 75/80% protection against symptomatic covid and 100% against hospitalisation and death. That's what I'm telling myself anyway.

I'm sure that I read the other day that it was 100% against severe illness, 79% against symptoms. One of the vaccines takes two weeks to take effect, the other three. I can't remember which way around though.

@Gerla

On the information given to me it says " 59.5% protection after two doses". I must admit I thought it would be higher but it wouldn't have put me off getting it.

59.5% protection against what though? Death? Severe illness? Symptomatic cases? Catching it at all? I'm pretty sure that it is the latter

AZ will have a lower rate as it’s the one used the most and as we focussed on the sick and elderly at first because they have low immunity the vaccine just isn’t as effective on them. That’s why the rate is so low - as more young people with stronger immune systems get vaccinated that rate will improve.

From a statistical perspective I would ignore the data from the UK as the press is regulated here. Focus on what’s coming out of India. From April they are going to vaccinate the largest population of young and healthy people any where on earth - yes there is the hygiene paradox there (people exposed to awful hygiene while young have stronger immunity against everything) but they also have a huge young middle class population that were raised in very hygienic conditions. So they will produce some great data and trends I think.

I've had my first AZ.

While I now have some protection after my first jab (29.5% to 68.4%) I am not comfortable in considering I am safe from serious illness for 7 or more days after the 2nd dose (90.3% to 97.6%)

Source

www.bmj.com/content/371/bmj.m4826

That source doesn't appear to mention the AZ vaccine at all.

@notangelinajolie that link shows data for Pfizer not AZ

@notangelinajolie, as discussed upthread, you don’t have a certain percentage of immunity as an individual. Those percentages are the number of people who have a certain level of immunity after vaccination. But yes, you’re more likely to be protected after your second dose.

It's all very confusing

@DdraigGoch

I'm sure that I read the other day that it was 100% against severe illness, 79% against symptoms. One of the vaccines takes two weeks to take effect, the other three. I can't remember which way around though.

That was an 'unfortunate' press release from Oxford/AZ with the number being based on outdated data. The actual number has turned out to be slightly lower than this, but not much.

Either way it's better than not having had any vaccine at all as long as people don't massively change their behaviour before we have more info.

So... let's say efficacy is 76% for arguments sake, 76 people out of 100 will experience no symptoms of covid. The remaining 26% will get symptoms... but not severe enough to require hospital or lead to death.

Is that right?

Not quite @Dementedswan

Efficacy is the proportional reduction in disease in the vaccinated group in a clinical trial compared to the unvaccinated group.

Effectiveness/efficiency is the same but in the general population after a vaccine is in general use.

So say in a clinical trial you have 1000 people in the vaccinated group and 1000 people in the unvaccinated group.

In the vaccinated group 1 person becomes infected with the virus.
In the unvaccinated group 30 people become infected with the virus.

The infection risk for the vaccinated group is 1/1000 or 0.1%
The infection risk for the unvaccinated group is 30/1000 or 3%

The vaccine efficacy is calculated by:

(risk of infection in unvaccinated group - risk of infection in unvaccinated group)/risk of infection in unvaccinated group

So (3%-0.1%)/3% = 2.9%/3% = 97% efficacy

Preempting anyone who says hang on 2.9/3 is 0.97, don't forget 2.9% actually means 2.9/100

Sorry obviously I mean:

(risk of infection in unvaccinated group - risk of infection in vaccinated group)/risk of infection in unvaccinated group

I'm still confused

Are you a betting woman (man?) @Dementedswan?

I can try explaining it terms of odds...