We don’t know the impact of vaccines on transmission yet. Here’s some speculation about when we do

[PuzzledObserver]

I am getting fed up of reading “but the vaccines don’t stop you catching or passing the virus on, they only stop you getting seriously ill”, because that is inaccurate.

An accurate statement would be “We do not yet have evidence about whether people who have been vaccinated can still carry and pass on the virus.”

So, until we do know, we are making the cautious assumption that they can, and telling people they must still follow SD rules after they’ve been vaccinated.

What is also true is that people who design vaccines and know how they work expect them to reduce transmission. I think the BioNTech guy said that, but he would only be guessing by how much. Eventually, however, we will have data. They are collecting it right now.

So - come speculate with me! Imagine three scenarios:

1. Vaccines reduce transmission by 20%

This would go some way to reducing the impact of more infectious variants, but is not enough to allow for any change to SD policy.

2. Vaccines reduce transmission by 50%

This is significant, and will be a big help in reducing the R number. I wonder whether it might also help to persuade some health or care workers who are declining the vaccine in part because their personal risk from Covid is very low and “it wouldn’t stop me passing it on anyway, so there’s no point.”

3. Vaccines reduce transmission by 80%

This will be a massive help in slowing transmission right down. Obviously still the more people vaccinated the better, but we will reach herd immunity at a lower percentage of the population vaccinated if this is the case.

I wonder if it may also be the gateway to allowing larger gatherings of vaccinated people? Although, on the social level I think it’s a bad idea to have different rules depending on vaccination status.

Sorry @PuzzledObserver but this is pointless speculation. Let's wait until we have some actual data.

How long will it take for us to find out if the vaccine reduces transmission? I'm pretty ignorant about stuff like this.

What's the point in speculating though? I agree with @Bilgepumper.

Let’s say it was a gateway for allowing vaccinated people to gather in larger groups, would this exclude people who are unvaccinated by choice and also those who could not be vaccinated?

@Bilgepumper, @Sparklingbrook - some people, including me, find it interesting. You don’t, and that’s fine. So don’t join in.

@Waxonwaxoff0 - I don’t know - I don’t know much about the detail either. I just have this instinctive belief that they will be able to model it, and I think I read that they are doing trials right now.

@reformedcharacters - that would depend whether it was guidance/advice, or law. As already indicated, I don’t believe that making it law would be a good idea for social cohesion.

It puts me in mind of the situation early on in the pandemic, when the advice to people over 70 to stay at home at much as possible. My church spent hours agonising and debating what to do about that, and concluded that while we could and should not ban the over 70’s from attending, we did have a responsibility to make them aware of the government advice. We did however decide not to allow any over 70’s to steward services for the time being. Subsequently, we have relaxed that and left it as their own choice.

So I could imagine a point at which legal restrictions on gatherings were eased, but people who have not yet been vaccinated were advised to be more cautious and limit their exposure to other unvaccinated people as much as possible. Some would follow that advice and others not.

That's me told.

All 3 scenarios don’t take into account what the vaccine uptake will be. Even a 50% reduction won’t have much impact if only 50% of people have it. 🤷‍♀️

@Covidcorvid

All 3 scenarios don’t take into account what the vaccine uptake will be. Even a 50% reduction won’t have much impact if only 50% of people have it. 🤷‍♀️

Well, that’s true. Do you think only 50% of people will have it, and if so, why? The last survey I saw, over 80% of people in the Uk said they would.

@Sparklingbrook I didn’t intend to send you away with a flea in your ear, sorry if it came across that way.

It’s just... you can find discussions about absolutely anything on t’internet, many of which are of no interest to me whatsoever. Train spotting, for example. And grouting. I do however find thought experiments interesting. Should I tell the train spotters and grouters to stop wasting their time.... or leave them to it, do you think?

I’m not sure. I hope it’s as high as 80%. Ive seen the figure 60% bandied about.

I may be overly skeptical but I feel like they have a clearer idea than they are letting on, and they will delay releasing it until cases are much much lower, as it would undermine lockdown compliance. But perhaps I watched too much X Files as a child!

That’s a good thought, @turkeymince.

I think it’s entirely appropriate for the government to hold back some information for a period. They need time to work out strategies in response to the data, and it generally works better if they can announce both together. If they announce the data in isolation, the inevitable question is “what are you going to do about it?”

If they said "we don't know yet if the vaccine stops transmission" then a good proportion of people will hear "the vaccine stops transmission".

Think of the number of threads on here that start with something along the lines of "I have a 5yo..." and then the second answer is "it would help if you told us how old your dc is."

[quote PuzzledObserver]@Sparklingbrook I didn’t intend to send you away with a flea in your ear, sorry if it came across that way.

It’s just... you can find discussions about absolutely anything on t’internet, many of which are of no interest to me whatsoever. Train spotting, for example. And grouting. I do however find thought experiments interesting. Should I tell the train spotters and grouters to stop wasting their time.... or leave them to it, do you think?[/quote]
It's just balance isn't it? People are allowed to have an opinion on a thread. Especially speculative ones during a pandemic.

I am impressed with correct topic selection though-not in AIBU.

I'll leave you be now.

@Covidcorvid

I’m not sure. I hope it’s as high as 80%. Ive seen the figure 60% bandied about.

Hancock gave an example of a surgery he went to today that so far had 98% of over 80's take it up.

We will know in a month or so based on Israel. They are vaccinating everyone with the Pfizer/BioNtech vaccine and are collecting detailed data which they are passing back to the companies. BioNTech totally expect an impact on transmission - as frankly with every other vaccine - but don’t yet know how much.

The main question I have is that this is great for the Pfizer vaccine, but we also need to know about the Oxford vaccine and so need an analysis for this.

@Covidcorvid

I’m not sure. I hope it’s as high as 80%. Ive seen the figure 60% bandied about.

I think it was today I read somewhere that 80% of brits were happy to have the vaccine which is 10% above the amount needed for herd immunity and really quite brilliant if true. Will try and fine a link.

*find

Presumably there is a difference between two possible ways of passing it on despite having the vaccine: a) those who still get ill albeit more mildly (which could be reasonably high numbers, depending on which stats for efficiency you read), who might be expected to still pass it on to the extent that they are still coughing/sneezing etc, and b) those who seem to have enough antibodies to make them immune, but who might or might not still be able to pass the virus on without actually getting ill themselves.

I presume most people are talking about the second thing, passing it on despite not being ill (or only asymptomatically), but there will also be those who do still get it because the vaccine doesn't work for them and/or it only partially works. One of the people I know in the AZ trial is in this category - got both doses of the vaccine several months ago, but was diagnosed with Covid last month, had it relatively mildly, but not asymptomatically. She assumes that the vaccines did what they were expected to do by reducing the severity, but I had hoped that in most people, they would actually be more preventative than that.

My sister (nurse) had her first dose of the Pfizer vaccine on 7th Jan, then tested positive just under 2 weeks later. She had minimal symptoms of sore throat and a stuffy nose, which only lasted a couple of days, and is now fine. So much so that she is wondering whether it was a false positive.

The interesting thing is that her DH tested positive a couple of months ago after being pinged as a close contact of someone who had tested positive. He never had any symptoms - and she didn’t catch it from him then. She had to have two negative tests on days 5 and 10 before she was allowed back to work.

I think that the combination of the strict lockdown and the vaccination program is going to bring the number of deaths and hospitalisations down dramatically. The government has to keep scaring everyone with the current high death numbers and busyness of the nhs (all true and I am not minimising that) and also suggesting that the vaccine will not stop transmission in order to keep the lockdown going long enough to bring the numbers down significantly before they relax anything. They keep playing down the falling new case numbers as "early signs that may not be significant". Give it three or four weeks and things will look very different and it will be harder to keep the public on board.