Thread by @ariehkovler

As Israel seems to have beaten its fourth Covid wave – this one a Delta variant wave – some observations. 1/

arieh.substack.com/p/israels-delt…

At the beginning of the wave in July, it seemed like something was off. Despite Israel's very high vaccination rate, Delta was spreading widely among both unvaccinated and vaccinated people.

arieh.substack.com/p/inside-israe…

I say "despite Israel's very high vaccination rate", but actually Israel's vaccination rate isn't so hot anymore when compared to many industrialised countries. 20% of the population is under 12, and vaccine resistance in the Arab population makes it hard to push beyond 70%.

But Israel vaccinated its population *early*, following Pfizer's protocol of 3 weeks between doses. That was good in February, but led to significantly reduced protectiveness from the vaccine now. 4/

At its peak effectiveness, the Pfizer vaccine is like 90-97% effective at preventing coronavirus *infection*. But in June/July, Israel saw barely any difference in infection rates between vaccinated and unvaccinated people in PCR testing. 5/

So Israel made what was then a controversial choice: booster doses. Starting with over-60s but quickly offered to anyone who was vaccinated more than 5 months ago. Takeup has been slow in younger agegroups, but 3.75M booster doses have been administered. 6/

Israel also re-introduced the Green Pass vaccine certificate, and announced that from October it would only be valid if your most recent vaccine dose was within in the last 6 months. 7/

And it worked. Big time. In July, most daily coronavirus cases were vaccinated. Today 69% are unvaccinated.

Only 6% of daily cases have had a vaccine dose (booster or second dose) in the last 6 months, despite this group being like 50%+ of the population.

Hospitals emptied of vaccinated people after boosters began. But the number of unvaccinated continued to rise throughout September, until the wave broke as boosters cut transmission chains and restored some level of population immunity.

(read the article re: the yellow line!)

Israel's Delta wave is collapsing quickly now, with daily cases back below the USA and UK.

For more discussion and analysis, read the full article at the Hat Tip: arieh.substack.com/p/israels-delt…

I'd be interested in comparisons to the UK, where the picture is so different: very high daily infections but relatively low hospitalisations and deaths. In July, the UK looked like a model for Israel but the reality was quite different as hospitals filled up and deaths mounted.