When can we start to see the vaccine saving lives?

[notevenat20]

We are told 88% of covid deaths come from groups 1-4. Already 11 million of those have been vaccinated and pretty much all of them will have been done in a weeks time. Full protection comes in about 21 days after vaccination but there is some protection from about day 14. This is all to say, should we expect deaths to plummet this month? I am really hoping so.

I've got no patience with such dangerous counter-factual bullshit

Agree with that reaction, but I do have some patience because there is worthwhile protection from the first shot.

But trying to drown out the full, evidence-based picture is of course very wrong

@sansaSnark, the latest research suggests that by day 21 the efficacy from Pfizer is around 90%: www.medrxiv.org/content/10.1101/2021.02.01.21250957v1

Pfizer efficacy after one does is 89% and after two doses is 91%.

Oxford efficacy after one dose is zero deaths, serious disease and hospitalisation.

I really hope so - must be awful for families knowing how close people were to vaccine.

What will be interesting in a few months is how many people in ICU were in the groups not yet eligible for a vaccine.

yes, I think we all know what the trial data says

Also that full expected level of vaccine protection comes with 2 shots not 1

All the early vaccines were of course Pfizer - so with the 3 weeks required to see the vaccine take, there are very few AZ reaching single-shot levels of protection.

And of course effect on transmission is still to be adequately evidenced. That is an important unknown, even though the signs are hopeful

@FebFrosting it’s awful that we had such a massive wave just as the vaccine was being rolled out.

@NiceViper second jab is more for longevity of protection than absolute level.

Yes, the day the AZ vaccine was approved was the day that I realised that I had Covid, I lost my smell and taste. I was upset, been waiting and staying in all year for the vaccine. I was one of the lucky ones and not badly affected.

I heard a virologist on BBC saying that you could treat the illness as like the first dose of a vaccine so when I get mine (group 6) it should act like a booster, hoping that is true.

I still worry about the mutant strains and reinfection.

@StealthPolarBear

As a pp said the first dose provides the majority of the protection. Why do people seem intent on denying this?

Because people are pissed off that the government decided to delay the second vaccine. Despite the fact that it's one of the only smart and effective actions the government have taken throughout the entire pandemic.

@SansaSnark

The first vaccine has just over 50% efficacy. For the Oxford vaccine, the second vaccine pushes it up to nearly 90%. For Pfizer, the second vaccine given on the correct schedule gives it over 95% efficacy.

52% efficacy from the first Pfizer jab was if you count cases across the whole 21 days between first and second jab. If however you look at cases after the vaccine starts to work, which is after 12 days, then the reduction between then and 21 days is 90%. We don’t know from the Pfizer trial what happens to efficacy when the second dose is delayed.

For the Oxford vaccine, there is a paper currently being peer reviewed which showed 76% efficacy 21 days after the first jab. When the 2nd jab is given at 12 weeks, it rises to 82.4%

So the statement that the majority of the protection comes from the first jab is true for both Oxford and Pfizer

papers.ssrn.com/sol3/papers.cfm?abstract_id=3777268

@StealthPolarBear

As a pp said the first dose provides the majority of the protection. Why do people seem intent on denying this?

Because they dont want to come out of lockdown.

OP there are many reports it’s already happening. The figures have been declining since mid January

I think it's nothing to do with attitudes to lockdown, and considerably linked to understanding of the science.

There is a great deal to be positive about from the expected level of protection from the first shot.

But bordering on wilful ignorance to diminish both the importance of completing the course or the surveillance work that is going on now (including heterologous immunity, which is tangential to this thread but very much to do with how and when immune responses occur)

1Oxford University conducted the so-called Oxford trial in UK and Brazil, and we have data for patients who received the vaccine in one-month interval, 2 or 3 months interval. First of all, we believe that the efficacy of one dose is sufficient: 100 percent protection against severe disease and hospitalisation, and 71-73 percent of efficacy overall. The second dose is needed for long term protection. But you get a better efficiency if you get the 2nd dose later than earlier.

2One dose of Oxford vaccine: - 76% efficacy against symptomatic covid after day 22. - 100% effective at stopping hospitalisations after day 22. Two doses of Oxford vaccine: - 54% reduction in transmission -Antibody response stronger after longer interval between dose.

3Tracy

They have reported a decline in hospital staff infections. Which most believe is due to transmission being reduced because of jabs.

The NHS staff being some of the first to get vaccinations. Still to early to be sure but good sign all the same.

@NiceViper But bordering on wilful ignorance to diminish both the importance of completing the course

Nobody is saying that it is not important to complete the course. It is important for vaccine longevity. People are just saying that we will see an effect post first dose if we are to believe the data coming out of Israel and the vaccine trials.

You don't think at a population level, 50% protection for those most at risk will have a huge impact on hospitalisation and deaths?!

@Blessex

My comment arose from the one about lockdown, which was antiscientific

No one is saying that first dose does not confer useful protection - I do not know how that strawman came out the basic fact that the full course is two shots.

@StealthPolarBear

You don't think at a population level, 50% protection for those most at risk will have a huge impact on hospitalisation and deaths?!

Of course not, and that is why I have not said that

If the only vaccine that had been developed had 50% efficacy after two doses it would have still been fantastic news back in December. Our expectations have hugely risen because the vaccines are so good and now, as with most things, people are confused between risk reduction (possible and sensible) and risk elimination (impossible).

Nice viper, apologies I wasn't aiming it at anyone in particular and probably not you. Just the people who are adamant that without the ssecond dose this is no good. At a population level this wil be amazing.

@StealthPolarBear

If the only vaccine that had been developed had 50% efficacy after two doses it would have still been fantastic news back in December. Our expectations have hugely risen because the vaccines are so good and now, as with most things, people are confused between risk reduction (possible and sensible) and risk elimination (impossible).

This

I think the frustration is every time anyone shares genuinely good news about the vaccine rollout, someone pops up with a wagging finger to say, "No! All these people are only HALF vaccinated!".

It is of course true that most people have only had one dose. It is of course true that is it is important to finish the course. Noone is saying that it is not.

It is also true that all the evidence is that a single dose gives very good immunity which, certainly in the case of Oxford and likely in the case of Pfizer, will last for long enough to get us through this very grim winter.

It is genuinely extremely frustrating to see the same misquoted statistics over and over again. "One dose only gives 50% protection" and similar. As @NiceViper says, we all are familiar with the evidence base and the current evidence base is that, after 3 weeks, the protection from one dose is very significantly better than that.

This is not to say that the second dose isn't important; it is. It is not to say that the evidence base will not continue to evolve; it will. As I have said elsewhere, the comparisons between the outcomes of the UK and EU vaccination strategies are going to produce a flurry of fascinating graphs in the next few weeks.

But, right now, the UK has around 20% of the adult population who have (or who in a couple of weeks will have) a very good level of protection whilst they await their second doses. There are already early signs that this is impacting on case numbers in those cohorts. It will inevitably have a snowballing impact on serious cases, hospitalisations, and death. As we were told in October, this is all now 'baked in'.

And I am rapidly running out of patience with doom-mongers spreading snippets of misunderstood information that seek to undermine that reality.

The important part is that while 21% of the population have had the first jab, its the 21% of the population who are most likely to need hospital treatment and potentially die from covid, so yes, even if this group is only 50% protected, its reducing by 50% the group who are the most likely to effect numbers of hospital admissions and deaths.

Right now, deaths and hospital numbers are coming down, but so are infections. Its not clear if the lockdown is having the effect (the vulnerable groups aren't being exposed to covid) or if its the vaccine (they are being exposed but not getting sick/dying).

I suppose we could say when infection numbers are high but hospital numbers are down that its had a positive effect? Bit of a risk though.

Yes what the last two posters have said