There seems to be a major flaw in comparing the data between the two studies: the Pfizer paper is counting Covid19 cases (symptomatic cases with confirmed PCR for SARS-CoV-2), while the Maccabi paper seems to be counting SARS-CoV-2 infections overall, which would include asymptomatic cases.

They even say so explicitly:

> Second, our case definition was positive SARS-CoV-2 PCR test irrespective to presenting symptoms that defined COVID-19 cases in the RCT. This might explain the discrepancy in results.

So, this new research is not really contradicting the Pfizer paper in any way - they are simply measuring different quantities.

Still, it's nice to know that the vaccine also offers protection from infection, not just the disease.

You're mixing up two different datasets. The former deals with first dose effectiveness (which we've always known to be lower - that's why the regiment is two doses), the latter with the full two dose regiment.

Ynet is Yediot, which is either the biggest daily newspaper or the second-biggest depending on how you count, either way it has more influence than Yisrael-Hayom. They do neglect their English site, but this particular content matches their Hebrew publication. It can't be seriously compared to USA Today (which is one of those magazine you mainly get for free, and barely has any dedicated readership).

Please look at the graphs and data, not the headlines.

Nothing magical happens past day 12 from the first vaccine in the Pfizer paper, or day 18 in this paper. Seriously. Look at it.

Yes, ynetnews is ynet/yediot. Their reporting of covid is exactly parroting the government with no criticism whatsoever so far.

I’m not antivax, I’m provad. 50% is pretty damn good for a first attempt. But everything has become so political, I go read primary data - and it is NOT remotely close to what the headlines say.

Edit: looking at the graph [1] more closely, I understand what you meant - there is no visible change in the slope past day 12 after dose 1 (dose 2 was administered on day 21). So the patient data actually shows that the vaccine achieved its maximum efficacy ~12 days after the 1st dose, not necessarily related to the 2nd dose at all.

Original comment:

I don't know where you're getting this, but the Pfizer paper [0] clearly shows that disease prevalence is much lower after the second dose:

> Among participants with and those without evidence of prior SARS CoV-2 infection, 9 cases of Covid-19 at least 7 days after the second dose were observed among vaccine recipients and 169 among placebo recipients, corresponding to 94.6% vaccine efficacy (95% CI, 89.9 to 97.3).

> Between the first dose and the second dose, 39 cases in the BNT162b2 group and 82 cases in the placebo group were observed, resulting in a vaccine efficacy of 52% (95% CI, 29.5 to 68.4) during this interval and indicating early protection by the vaccine, starting as soon as 12 days after the first dose.

You are right about the severe cases though - they had 1 in the vaccine group and 4 in the placebo group, which is far too little data to draw any meaningful conclusions from (it's also worth noting that the single severe case in the vaccinated group occurred >7 days after the second dose, so there is absolutely no data to draw conclusions on severe disease impact with a single dose).

[0] https://www.nejm.org/doi/full/10.1056/NEJMoa2034577 [1] https://www.nejm.org/na101/home/literatum/publisher/mms/jour...

Indeed that is what I meant. Thanks for trying to understand even if I wasn't perfectly clear in my wording.

Indeed, maximum efficiency is achieved after 12 days in Pfizer data (and similarly in the Israeli data). That's the reason some countries consider giving just one - they suspect it won't be as-long-lasting without the booster, but that's from prior experience, not anything specific for this vaccine.

I'm incredibly frustrated at the amount of people parroting "yes, two weeks after the first vaccine it's 50%, two weeks after the 2nd it's 95%". Yes, that's what Pfizer said, and I think I managed to reproduce their calculation - and if I did, it is intentionally misleading.

It seems a lot of people are religiously believing the headlines without looking at the publicly available data. I thank you for looking at it.

I'm not referring to the Pfizer research, I'm referring to the Maccabi paper. The data is explicitly for the first dose and not the second. The paper also mentions the effect starts from day 18, not beforehand - maybe you should read it again.

What Maccabi did publish on the second dose, it was in a much more encouraging note. Granted, not a peer reviewed paper, that would be difficult given lack of time.

Claiming Yediot is parroting the government is delusional. I won't belabor about it, since most HN readers deserve better than Israeli politics or the eternal elections.

The main point that beagle3 makes is that the Pfizer study actually shows ~89% efficacy starting 12 days after the first dose, which improves to ~90% immediately after the 2nd dose (day 21) and ~95% 7 days later (day 28).

The Maccabi study was designed with this comparison in mind: they look at efficacy in days 1-12 and 13-24 after the first dose. They are mainly interested in comparing the Pfizer results for days 13-21 (89% efficacy) with real-world data. They show that the real world data is actually showing only ~50% protection in days 13-21, compared to 89% in the Pfizer data for the same period. This is somewhat disheartening.

HOWEVER, the Maccabi paper is not measuring the same thing as the Pfizer study. The Pfizer study only looked at symptomatic infections (Covid19 symptoms + positive PCR for SARS-CoV-2), while the Maccabi paper is also including asymptomatic infections.

Neither study includes sufficient data to accurately compare with the other one - the Pfizer study did not do PCR tests on anyone who didn't show symptoms, so we don't know how many asymptomatic infections they had exra; and the Maccabi study didn't record symptom information, so we don't know what percentage of those infected were symptomatic.

All of these numbers and facts are explicitly mentioned in the Maccabi study, it's not me reading into the data on my own.

You are correct, but this doesn't show a conspiracy like a certain other commenter hints at.

We always knew that the the Pfizer vaccine has a lower chance of preventing transmissions, the original treatment regime was two doses, and we further know that the Pfizer vaccine wasn't originally tested vs B117 and the other mutations and it's quite possible it has lower efficiency vs those.

Still, there's a good chance two doses offer even higher protection, and frankly if all adult population receives only the 'symptomatic' protection the plague will be over as far as Israel is concerned (barring yearly(?) boosters) - hearing there's any protection for asymptomatic infections is heartening.

No, it doesn’t show a conspiracy.

The political rather than medical decision making in Israel is out in the open, there’s no need for conspiracies.

It took @RanBalicer 3 days to acknowledge the abysmal data, and it was not “gee, we might have made a mistake in the model”, it’s always “an unexpected twist in the mutation/behaviour/population”. It is beyond embarrassing. But I digress.

Let’s just agree that the 95% RRR for “reported mild symptoms” is meaningless, and that the 50% number from Maccabi is actually good news, and we should use that number in models and predictions?

I don't have an anti for Balicer, so I don't care if his models are right-or-wrong. It's natural to have mistakes, and changing position after 'only' 3 days is fine enough. I also agree that we heard some good news, but I do think that the 95% RRR is relevant - people who have a strong enough immune reaction to make the disease asymptomatic are people who have been protected. Once enough people have been protected, than hospital burden will go down and Israel could manage this thing.

The 2nd dose data maccabi sent out is pure PR; It's basically "We finished vaccinating yesterday, and almost no one got sick yet!" which, while true, is the most fudgible statistic ever. I'm ignoring it and waiting for the 2nd paper from Maccabi and the 2nd release from the K(alkstein) Institute - whom I trust more than even the Maccabi medarxiv paper (and I do trust them, about a billion times more than government press releases and the incredibly compliant mass media).

Please stop spreading lies. The paper is only about "The effectiveness of the first dose of BNT162 ..."

50% efficacy after the first dose is exactly the number that BioNTech reported in its Phase3 trial. So nothing unusual here. That is why the 2nd booster shot is needed to get to 95%.

See my other reply to the other copy of your comment.

Please prove that you actually read the Pfizer report and not just repeating headlines before calling me a lier.

I might have misread some data, but I see no indication that you are in a position to judge that.