On Vaccinations Programmes and Normality in September 2021

[danieldwilliam]

My thoughts on a vaccine roll out. It will be September 2021 before anything close to normality returns.
(This is one of those blogposts mostly to layout my thinking and force myself to think something through rather than an attempt to Dunning-Krueger myself or to be oracular.)
The noises from vaccine developers seem muted but nobody has reported a massive failure. Certainly not everybody has reported a massive failure yet.
So we are probably 12 months in to an 18 month process.
That would indicate some sort of effective vaccine being announced in January / February with large scale access to it starting in February / March.
My assumptions for the first round of vaccines are
1) they have limited effectiveness compared to our usual experience of vaccines - fewer people than normal will find them protective and the protection will be less than we usually expect.
2) they will have a more time-bounded effectiveness than we are used to - perhaps six months, or 12 months
3) they will have more side-effects than we usually see, making them either unpleasant for some people or unsuitable for some people.
So useful but not a complete answer to the problem.
I'm assuming that production in the West will be geared up to provide vaccines for their entire populations over a 12-month period with say 10% surplus to be shared / exported / donated with the not-West. China will probably sort itself out quicker. Ditto the South East Asian countries with experience of SARS. Other countries will sort themselves out slower.
There will be a second round of vaccines following on about a year from the first round, these will be better in terms of protection, duration and side-effects.
By the time the vaccination programme starts in the UK I think we'll have had about 5% of the population having had the virus in a way that confers some on-going immunity from the point when the vaccine programme starts. (I'm assuming here lots of asymptomatic cases which have not been spotted.) But I'm also assuming enough churn in immunity to keep that number at 5% through out.
Assume the UK has access to a total of 60 million doses over a 12-month period, or 5 million a month, or 7% of the population a month. Then our immunity level starting in March is 5%. It rises to 12% by the end of April. By the end of September 2021, it's a 60%.
In September we start to see people who only gained a short period of immunity from the vaccine they had in March / April / May become less immune. So, our rate of increase in immunity levels slows.
60% - 70% is probably not enough for herd immunity to kick in. I believe a figure of 80% of the population having some form of immunity is required for a disease as contagious as COVID-19. However, it does mean the spread will be slower. This should help Track and Trace operations.
It would also allow those who have been vaccinated to move around with more liberty and for the country to preferentially vaccinate those who are a) at the most risk of dying b) those at the most risk of spreading the disease.
So, we might see a a limited return to normality around September next year.

Comments

[cmcmck]

There is an argument that the sooner a vaccine starts to be used once (if) available, the better.

[rhythmaning]

This paper suggests 94% exposure to the virus or vaccine may be necessary for herd immunity. (I was curious and this was the first paper I found, not necessarily the best! This one, updated a couple of weeks ago, puts it anywhere between 50 and 90%, so 80% would be a good guestimate.)

Is there any reason for what seem pessimistic assumptions? Though better to err on the pessimistic side... "It'll be all over by Christmas [2021]..."!

[danieldwilliam]

To be honest, other than the risk that it has nasty and hidden side effects, I can't think of an argument for not bringing it out as quickly as possible but I think there is a limit to the amount of physical production capacity that can be set up.

Mind you, I think I might not put myself at the very front of a queue for a vaccine - given that I'm not in a high risk group and not significantly economically impacted by the virus directly.

[danieldwilliam]

Partly just natural caution about prediction making.

Partly a bit of a psychological buffer against being too optimisitic.

Partly my general assumption that big project, especially those run by a modern state, tend to take a while to get started.

Partly a specific view in the case of early vaccines that we will prioritise getting something useful in to production soonest over getting the best thing in to production a bit later on - but this implies that the things we get in to production soonest won't necessarily be the best. Hopefully I'm wrong on that and we happen to find the best option early on.

[mountainkiss]

Probably supportive of basic thesis but would observe that the winter six-month period will be much worse than the summer one.

[danieldwilliam]

Worse in the sense of social isolation etc?

[mountainkiss]

(1) colder so can do less outside.

(2) colder so more spread of virus so more restrictions.

(3) less outside so more inside so more spread of virus so more restrictions.

(4) colder and darker so people are sadder.

[danieldwilliam]

Yeah, all of that makes for a more miserable six months.

[naath]

Production of several vaccine candidates is already ramping up; but there will be supply chain limitations.

[danieldwilliam]

When you say production do you mean factories producing them by the tens of thousands for distribution to the public or batches of hundreds being produced for testing of candidates?

[woodpijn.livejournal.com]

How are we 12 months into an 18-month process when the pandemic hasn't been going on for 12 months? Do you mean 6 months into it?

[naath]

The former; some vaccine candidates have got financial backers to make that (large) gamble. I don't have exact details, but I expect a vaccine to hit the ground running; if not at "7 billion doses ready to go" levels. But, y'know, we're in the middle of sodding up a perfectly routine seasonal 'flu vaccination programme, so maybe I'm being super optimistic (The UK mostly knows how to distribute such a vaccine once it has it although world wide coverage will be much slower, there are vaccination programs in place almost everywhere (I do not envy whoever is coordinating Syria, amongst other active war zones))

[danieldwilliam]

Maybe not 12 months. I'd misremembered when China had first detected the virus as a bit earlier than December 2019. 10 months in to an 18 month process.

[danieldwilliam]

Right, so to get this clear in my brain, you think the factories to produce the mass vaccines have financing and / or are in the early stages of being built already and so will be ready to produce large numbers of vaccines pretty much as soon as the vaccines are approved for use? Have I understood that correctly?

If so, I think that is my current assumption also and underpins my guess that large scale production starts shortly after approval. Instead of say, 6 months after approval.

[danieldwilliam]

What have we done with the 'flu vaccine?

I do not envy those working in Syria, Yemen, Afghanistan or Brazil to be honest - that's going to be hard work and probably dangerous.

[naath]

have you tried to get one? (unsure what we DID per se, but you can't get it)

[naath]

no, I am saying (although I could of course be wrong) that at the pint of approval there will be millions of doses ready to ship (of some vaccines). And the UK has at least the outline of a distribution plan (who gets these doses). (one doesn't aiui build new factories, but re-purpose existing ones) see eg: https://www.sciencefocus.com/news/coronavirus-manufacturing-begins-on-millions-of-doses-of-the-oxford-vaccine-candidate/

[danieldwilliam]

I have not tried to get one but I do have a drama pal who has mentioned that she's struggled. I'd put that down to her living in the Scottish countryside during a plague and being unlucky.

That's not good.

[danieldwilliam]

Aha! Thanks for bearing with me.

That is good news and would accelerate my time table by a few months. At least. Awesome.

I may get to go and see something in the Edinburgh Fringe for my birthday after all.

[naath]

OK, some people have got it, but lots of people can't, including many who get it free