💉🦠Vaccine effectiveness (VE) in Israel still high:
There has been much discussion recently regarding current estimate of VE - raw numbers normalised naively based on cases and national vax% seem to imply that for older age groups, VE is low or even 0🧵
This normalisation uses the national avg for vax%, assuming that the cases come from an even distribution from the total population.
The distribution of cases since June doesn't represent the entire population; it is skewed towards higher SES cities with higher vax%>>>
This is very important - the implication is that VE may actually be significantly higher than it seems from the data in 1st tweet.
This confounder was mentioned by several people incl. @GazitDoron & @dvir_a.

Some data wrangling + analysis produced this plot.
- Top row: cities with most COVID cases between 1/6/21 - 5/7/21 (time frame that would affect current severe cases).
- Bottom row: estimated* vax rate for ages 70+ in each city

* "Estimated"-more in next tweet>>>
(This is an estimate. Vax rate appears to be >1 in some cities d/t the vagaries of data availability. While the exact number of vax given is known, the actual number of people in each population group per city is an estimate based on @lamas_dovrut data)
Calculating an estimate of the weighted vax% for the infected population is now possible:
>98% for ages 70+.
This yields a vaccine effectiveness of 90% in preventing severe COVID!
Even if we take a more conservative estimate of 97% vax, VE for severe COVID = 85%.
This is just a rough estimate based on incomplete data. There are still multiple caveats to consider including differences in behaviour between populations, small sample size, and more.
But bottom line is I think current data supports high VE in preventing severe COVID in Israel

• • •

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

Keep Current with Yair Lewis

Yair Lewis 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 @_lewisy

17 Jul
Latest update from Singapore MoH regarding cases in the past 28d, by vax status:
* 386 total cases
* 97 of those in fully vaccinated
* 0 fully vaccinated requiring O2 / ICU / death!
Some thoughts based on a quick and dirty analysis of these numbers>>>
bit.ly/2VOQNBb Image
Singapore is interesting to follow regarding possible #Delta effect:
* Delta became the dominant strain there in April
* Vaccinations are exclusively w/ mRNA
* Vaccines have mostly been given since April, negating potential "immunity decline" confounders Image
Around 35% of population was fully vaccinated during the period shown above.
Therefore, one would expect ~15 fully vaxed cases if vaccine effectiveness (VE) against infection was 90%.
Based on 97 cases, naive VE for infection is much lower*

* Confounders galore!!! I know
Read 5 tweets
10 Jun
💉Israel #COVID19 update, week ending June 6th:

- 105 total cases
- 74 of those in the unvaccinated pop (3,835,144 people) = 1.93 cases per 100k.
- 3 in partially vaccinated (342,620) = 0.88 per 100k.
- 28 in fully* vaccinated (5,113,236) = 0.55 per 100k.

*14d post 2nd

* In Israel still extremely low COVID numbers without no evidence of resurgence; contrasts with UK data
* No restrictions - everything is open. Most people not masking indoors
* UK & Israel both with very high vaccination rates, so why are we seeing different disease dynamics?
I'm sure there are better theories about this, but here are a few possibilities:
1. Mounting evidence of importance of 2nd vax vs. variants (60%🇮🇱 / 42%🇬🇧)
2. Stricter border policy in Israel - mandatory PCR testing on arrival, no entry from "red" countries
3. No one really knows
Read 4 tweets
28 Apr
💉Israel #COVID19 update for week ending April 17th:

- 993 total cases
- 812 of those in the unvaccinated pop (3,947,127 people) = 20.57 cases per 100k.
- 50 in partially vaccinated (520,743) = 9.6 per 100k.
- 131 in fully* vaccinated (4,823,130) = 2.7 per 100k.

*14d post 2nd
Schools, restaurants, bars, etc all open.
Masks only in indoor public settings
1 dose is good, but in this week in Israel the #COVID19 case rate for those only partially vaccinated was x3.5 times higher than those fully vaccinated
cc: @EricTopol @MonicaGandhi9 @MackayIM @sailorrooscout
Read 6 tweets
26 Feb
Excited to see our paper published by @CDCMMWR!
Great collaboration with the amazing @EhudR4 🙏
We showed the population-level effectiveness of COVID-19 vaccination in preventing severe disease requiring mechanical ventilation.
Short explainer👇
We analysed the publicly available COVID-19 vaccination and cases data from Israel, and compared the daily number of ventilated patients in the highly vaccinated >70 age group with the under-50 age group (low vaccine coverage).
The ratio of COVID-19 patients over 70 years old to patients under 50 years old requiring mechanical ventilation decreased by 67% as compared with rates before the vaccination program.
Read 9 tweets
17 Jan
#COVID in Israel, thread with some possible explanations.
Within the last 4wks:
1. Massive vaccination campaign, with ~80% of the >60 population vaccinated.
2. A third national lockdown declared.
3. Huge surge in cases and deaths.
@EricTopol and others ask "what is going on?"
The question being, why have we yet to see a positive effect of both these dramatic measures?
Here are some important points to consider in this regard.
1. The vaccine campaign (correctly) targeted at-risk individuals, mainly the over-60 population.
2. Yet the drivers of the infection wave are the younger population, who have not been vaccinated up till now (rollout for younger people starting this week!).
3. The vaccination campaign is a success. But vacc % are low in some high-morbidity communities. See plot:
Read 6 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!