Many are confused by results that >1/2 of hospitalized in Israel are vaccinated, thinking this means vaccines don't work. I downloaded actual Israeli data… and show why these data provide strong evidence vaccines strongly protect vs. serious disease (1/8)
I have written an article detailing these calculations and explanations:…
BTW, published report when Israel had 152 hospitalized breakthrough infections showed 40% of these cases were immunocompromised & 96% had comorbidities, so serious delta breakthrough infections in those without preexisting conditions nearly non-existent.
A few notes:
1. The data set I downloaded includes only data age 12+ which is why the numbers don’t add up to Israel total population.
2. For brevity I omitted single dose vaccinated which is why the percentages don’t sum to one. Take 1-%full-%unvac to get %1dose
Note the 90.9 is a typo should be 91.9
Note the 90.9 is a typo should be 91.9
A few notes:
1. The data set I downloaded includes only data age 12+ which is why the numbers don’t add up to Israel total population.
2. For brevity I omitted single dose vaccinated which is why the percentages don’t sum to one. Take 1-%full-%unvac to get %1dose
Also, typos: 90.9 should be 91.9, and 2,170,563 should be 2,133,516.

The percentages, rates of severe cases and efficacy are unaffected -- these were just copy/paste typos in powerpoint

• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Prof Jeffrey S Morris

Prof Jeffrey S Morris Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @jsm2334

15 Sep
Data presented below show nearly 33% of unvaccinated adult Israeli residents were previously infected.

Why is this important & has this contributed to misinterpretation of Israeli data?

This thread wll explore these questions.
Israeli MoH releases periodic vaccination reports on its Telegram site. This table breaks down vaccination status by age groups as of September 14, 2021 listing total population and number given 1/2/3 doses plus those unvaccinated but recovered from previous infection
From these data, I constructed this table with % of population unvaccinated, given 1 dose, 2 doses, & 3 doses, & proportion of unvaccinated are previously infected.

Note that >30% of total unvaccinated Israelis were previously infected, & >1/3 for all age groups in 20-59yr
Read 13 tweets
15 Sep
I have seen a lot of people obsessing with Table 5 of the 8/21 UK Delta report:

402 Covid deaths among 47,008 fully vaccinated for case fatality rate 0.86%

253 Covid deaths among 151,054 unvaccinated for CFR=0.17%

Do vaccines increase CFR 5-fold?
They also split data out by age (<50/>50).

For older group, CFR for vaccinated (1.81%) is 3.3-fold LOWER than CFR for unvaccinated (5.96%)

For younger group, CFR for vaccinated (0.05%) is 1.5-fold higher than CFR for unvaccinated (0.03%), but there are only 13 deaths.
Another case of Simpson's paradox, since a confounding factor (age) is STRONGLY associated with both outcome (death) and exposure (vaccination status) given risk of death in old >>> young and vaccination rate old >>> young.
Read 6 tweets
12 Sep
How well are vaccines and boosters really protecting against COVID-19 deaths?

Israel MoH publicly posted daily COVID-19 death data split by unvaccinated, boosted, and vaccinated-not-boosted from Aug10-Sept8

Here are results of my analysis of these data
Summing over all days, it is not promising to see so many COVID-19 deaths in vaccinated/boosted groups.
But by now we know better than to draw conclusions from raw counts, right?
The Israeli MoH dashboard provides enough information to infer total proportion of population unvaccinated, boosted, or vaccinated-by-not-boosted, so we can compute normalized COVID-19 death rates in these groups.

Read 13 tweets
24 Aug
New medRXiv paper by UPenn group led by John Wherry looking at immune markers 6m after vaccination.

Partially explains waning vaccine efficacy vs. infection, more durable vaccine efficacy vs. severe disease, and is relevant to current booster policy.…
Paper measured immune markers (antibodies, T-cells, B-cells) from 61 individuals vaccinated with Pfizer/Moderna at 6 time points, from pre-vax to 6m post-vax.

16 were previously infected with SARS-CoV-2 and 45 SARS-CoV-2 naïve, and analysis was stratified by previous infection.
The key results were:
1.Neutralizing antibodies (NAbs) decreased over time
2.Memory B cells (Bcells) increased over time and did not wane
3.Helper T cells (T4) and Killer T cells (T8) dynamic described
Read 14 tweets
24 Aug
Great tweet by Monica Gandhi on new paper on transmission using the best way to track transmission: attack rate of virus after exposure in a rigorous contact tracing setting.

A few comments about what this might mean for transmissibility of breakthrough infections...
Although not dealing with breakthrough vs. unvaccinated infections, two results that are encouraging for the notion that breakthroughs might transmit less:
1. Asymptomatic infected were >4x less likely to transmit to others than symptomatic.

We know breakthrough cases are more likely to be asymptomatic, so this suggests one reason why breakthroughs might transmit less ...
Read 7 tweets
18 Aug
@CT_Bergstrom I agree Carl.
I will write a blog post on this but one possibility is that this is a combination of
1. unmeasured confounders (eg that young people vaccinated in January are Health care workers who are tested and exposed much more than those later vaccinated young people)
@CT_Bergstrom 2. Delta effect. Since we know delta spreads faster & with 50-100x viral load, it makes sense this higher viral exposure could lead to detectable virus that would produce “asymptomatic breakthrough infections” if testing done at right time, even if the vaccine works as intended
@CT_Bergstrom 3. And based on data I’ve seen showing memory B cells and helper T cells remain maxed out at 6m (and can produce new nAbs in 2-3 days)and nAbs and killer T cells decrease 10x but still remain 10-100x prevaccine baseline, it is possible that in early months the circulating nAbs..
Read 5 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!