Confused about Mum's 2nd Vaccination

[Icequeen01]

Just been watching the Government's Up-date but had to keep popping in and out of the room. My 81 year old mum has had her first Pfizer vaccination and was due to have her 2nd on 9th Jan. Will that now be changed to 3 months time?

The data itself actually shows a maximum of 68.4%. Please do not make things up.

The 68.4% figure is the maximum average at a 95% credible interval - according to Bayesian statistics. In (very) simple terms they are 95% certain that the average stated as 52% lies between 29.5% and 68.4%.

It is NOT the maximum efficacy at the end of the 21 days after the first dose.

@bumblingbovine49 Thank you, your post is really reassuring and has given me perspective.

@RhubarbFizz I don't think you sounded heartless at all and I know my DM is much luckier than most. I do hope your relatives get their first dose soon.

Yes, that is correct. It is the maximum in the range that produced the average.

The maximum efficiency at 21 days has nowhere been shown to be 90%.

@SpikySara - Is that true? I haven't read or heard that anywhere. Now I'm back to worrying!

There is an article in the Guardian about this:

More than 500,000 people who have been vaccinated against Covid-19 will have their second dose delayed for up to 12 weeks as the NHS rethinks the rollout that is aimed at halting the surging death toll in the UK.

In a change of policy, applying across the UK, the NHS will now prioritise administering to as many people on the priority list as possible the first dose of either the newly approved Oxford/AstraZeneca vaccine or the Pfizer/BioNTech jab, so as to maximise the number of people protected against the disease.

www.theguardian.com/world/2020/dec/30/covid-19-second-stage-nhs-vaccinations-delayed-across-uk

I personally think this is the wrong decision, it’s cruel to take surety away from our extremely vulnerable. And aren’t we just encouraging the evolution of a vaccine resistant variant half-vaccinating people like this?

Thank you @Em777 - funnily enough I had just found that article and was reading it. It doesn't state that Pfizer have said it won't work but it is still worrying.

@Icequeen01

Thank you *@Em777* - funnily enough I had just found that article and was reading it. It doesn't state that Pfizer have said it won't work but it is still worrying.

In your shoes I’d fight as hard as I could to get my mum that second shot (if it becomes an issue). I’m sure she’ll have some protection from one shot but it’s not the full protection she was promised.

I notice on Twitter there are HCP discussing this and planning to make noise within their trusts to ensure they get their second dose on time.

whilst the additional wait is frustrating and disappointing, I could live with that (for my Dad) but my main worry now is actually the lack of data to confirm that the additional wait won't reduce the efficacy of the 2 vaccinations overall. Is there even any data on this? As far as I can make out the pfizer vaccine was only trialled with a 3 week wait between doses, so we have no way of knowing what the effect of delaying the second dose would be do we? That is a massive gamble if you ask me. And quite apart of being devastated for my dad if it turns out to make it much less effective overall, what a massive waste of vaccinations that would be. Surely not a good idea at this stage??

@Icequeen01 The effectiveness of the Pfizer vaccine 12 days after one dose is 91%. The 52% figure was the average effectiveness of the vaccine in the 21 days after vaccine. This is an average of 11 days where there is basically no effect, and a further 10 days where it is ~90% effective.

This is shown in the graph attached from the research paper. The red line are the cases of covid in the Pfizer/BioNTech vaccine and the blue line cases of covid in the control group. For the first few days post vaccination, the two lines tracked each other. At around 11 days, it was a though a switch clicked in and the vaccine group is almost a flat line. Look at the small graph in the left hand corner. It’s amazing!

Everyone in the trial got the second dose at 21 days, but that had minimal impact compared to the first dose. They think the second dose makes it last longer, not that it is needed for protection.

Which is a long way to say that your mum is not safe

is safe

Thank you so much @Eyewhisker for explaining that in terms I can understand. I couldn't see the wood for the trees. That graph really is reassuring.

I have told my mum this morning who is understandably quite upset but when I explained that this means that there will be more of the vaccine to go around and hopefully her elderly friend will now get called she understood that this is the best way forward.

Unfortunately I'm due to return to work on Monday to an SEN school where SD is not possible. The school is part of a residential community and I have received news that some of the children and staff in one of the homes have the virus so things are going to be tricky for a while.

Pfizer is saying that they don't have any data for the degree of protection more than 3 weeks after dose 1.

I am all for decisions made in pursuit of the best public health outcome, but they need to be decisions made on evidence, and I don't see that there is any evidence base at all for this decision. There is simply no trial data available to answer this question.

@Mistigri

Pfizer is saying that they don't have any data for the degree of protection more than 3 weeks after dose 1.

I am all for decisions made in pursuit of the best public health outcome, but they need to be decisions made on evidence, and I don't see that there is any evidence base at all for this decision. There is simply no trial data available to answer this question.

This is correct. There is no trial data that states that vaccine efficacy is 90% after 21 days. The data that @Eyewhisker has linked to simply does not show this. It is purely an inference drawn from the existing data, but it is not conclusive.

There is no actual data because this (one dose only) was not a parameter during the trial. Therefore there is NO EVIDENCE that one dose is 90% effective after day 21.

It may be correct, but equally it may not. No-one knows.

The manufacturer has not stated that the evidence shows 90% efficacy after one dose. This is a political decision not a scientific one.

Glad to see that many healthcare professionals do not agree with the Government's attempt to completely alter the way that a NEW vaccine that has had limited testing should be used.

www.theguardian.com/society/2020/dec/31/covid-vaccine-uk-doctors-criticise-rescheduling-of-second-doses

This is a gift being handed to anti-vaxxers.