I had the Pfizer in February, no ill effects beyond any other vaccination. Waiting to get date for second shot and hoping "supply issues" won't delay it.

A lot of people said the UK, after delaying the second shot to 3 months against the manufacturers recommendation of 3 weeks, would experience a shortage after 3 months as they needed to catch up on the delayed second doses after the initial sprint, and that's what is happening it seems. How much of an advantage the strategy will be is yet to be seen, but the fear is that giving partial immunity could let vaccine resistant strains emerge.

UK infection numbers are fairly stable as of today, but not declining despite the continuing lockdown. Probably due to schools having been sent back. They appear to be gambling that while young people may get infected, the number of serious cases is quite small. Though this logic didn't help back at the end of 2020 when infection numbers went rocketing as schoolkids brought the virus home to parents, who took it into workplaces.

That's how my sister in law caught it - she works in a school. She was fine while the schools were on hold but within a couple of weeks of them going back she got it - and still has long covid issues.

It's early days yet for the viral mutation problem but there is some evidence to show that the virus may be constrained in what viable mutations are possible. The same relatively small number of convergent evolution changes seem to be showing up again and again. If that pans out it may make the vaccine manufacturers future life a little easier. Popular science article on the subject via the link below if you're interested -

https://www.scientificamerican.com/a...riable-so-far/

The statistics over the last few months have been that about 1 in ten of all new cases end up in hospital, and about one in three of those die. A sobering fact.

I wanted to see whether it was possible to measure the effect of the vaccine, so I took the 7-day rolling averages (smoothed) data for new cases, hospital admissions and deaths and plotted them. This didn't help much as the figures were so disparate, so I divided all the case figures by 21 and all the admissions by 2.5. In this way the start position of cases and admissions at the beginning of February was roughly level with the 1,150 deaths per day.

What you can see from the chart is that the blue cases line has reduced nicely due to a mix of lockdown and vaccinations, but the orange admissions line has reduced even more, and the grey deaths line more again. By measuring the difference between the blue (258) and grey (74) lines at the 25 March one might propose that the vaccine is currently saving 184 lives per day, or to put it another way, over 70% of deaths are being prevented.

It takes 2-3 weeks for the vaccine to become really effective and the effect of the vaccine on death rates will increase dramatically over the next couple of months as increasing numbers of the population are vaccinated.

I will admit this chart is REALLY crude as what I should have done is to factor in the typically ten day gap between reported new cases and admissions, and then the typically twenty days to death. But it was enough to satisfy my curiosity about the effectiveness of the vaccine.

Attached Thumbnails

 

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"For sheer delight there is nothing like altitude; it gives one the thrill of adventure
and enlarges the world in which you live," Irving Mather (1892-1966)

I was told info below by Astra Zeneca this morning when I telephoned them with regards to the efficiency of the vaccine AFTER you have had your FIRST injection

If you have your SECOND shot of the AZ vaccine:

• at < 6 weeks from the first injection then it offers 55.1% efficiency
• at between 6 and 8 weeks from the first shot then 59.7%
• from 9 to 11 weeks from the first shot then 72.3%
• At > 12 weeks from the first shot then 80%

If anyone would like to call them as well their number is: 0800 783 0033 option 8
Disclaimer:
I am not a medical professional- just a glad recipient of this vaccine and passing the info on- make of it what you will

Interesting statistics and there seems little doubt that a longer interval is positive, which is what many medical professionals said would be the case.

I did read the study in the Lancet and didn't quite understand why the efficacy of a second dose is only 55.1% when the efficacy of a single dose is 76%.

Also there's a load of variables discussed, "Important study limitations include the fact that these studies were not prospectively designed to establish whether vaccine efficacy would differ by dose interval; therefore, these post-hoc exploratory findings could be biased. Other limitations are that participants were not randomised to dosing interval, only one of the four trials was double-blind, and the single-dose recipients were self-selected. Furthermore, baseline characteristics between the single-dose and two-dose cohorts were substantially different, with an older median age, higher proportion of men and non-white participants, and a smaller proportion of health or social care workers in the two-dose cohort than in the single-dose cohort."

One of the criticisms of the Astrazeneca approval submissions is their somewhat random way of carrying out clinical trials, and it's difficult to ascertain reliable data.

__________________
"For sheer delight there is nothing like altitude; it gives one the thrill of adventure
and enlarges the world in which you live," Irving Mather (1892-1966)

I personally prefer to speak to the manufacturer direct-
As I said in my previous post:
"If anyone would like to call them as well their number is: 0800 783 0033 option 8
Disclaimer:
I am not a medical professional- just a glad recipient of this vaccine and passing the info on- make of it what you will"


All it takes is a free telephone call. I've even provided the A.Z number...

The difference in efficacy of single and second dose only depends in the numbers of participating people and the control group.

By statistical reasons you can`t break down the numbers to compare the results one to one between first and second shot groups. These numbers are imho hidden in the study of your link in brackets behind the percentage value but without full text version I cannot analize and explain.

This videos explains why you can`t compare vaccines only by percentages. It all depend on the circumstances of the study and their (different!) numbers of vaccinated people and of the control group.

https://youtu.be/K3odScka55A

hth

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I had the first AZ vax two weeks ago. Second jab scheduled for mid June (three months apart). No issues - bit of a sore arm, dull head for a day, bit tired for another day. Some of us who are "more mature" remember children at school who had Polio as a youngster. The vaccine and booster were later administered at schools. It is standard for all children these days. (BBC radio says (last month) polio is only in Pakistan and Bangladesh these days)

In the mid 70's I travelled throughout UK, all Europe and some communist countries in a old VW (LHD) sedan I bought in UK. (was half tempted to sell the car and buy a motorcycle in Holland - that is another story - never thought of shipping my bike).

In the mid seventies there was no internet, no GPS and no mobile phones (paper maps were very detailed). Crossing into most countries was interesting - as well as passport and vehicle insurance check it was often necessary to produce a small yellow folder detailing the vaccinations you have had. (After this was done it was then off to change currency).

Things are a bit easier these days which is a good thing

Proof of vaccination is today is achieved by a secure personal log into to an Government register.

Keen to minimise the virus so we can all get travelling again!