Some data that might explain Israel's peculiar vaccine effectiveness numbers.
It appears that the lower vaccination areas of Israel were not being hit till recently.
The vaccine effectiveness methodology the Israeli MOH was using has some potential confounders in it as it doesn't compare tested populations, but national vaccination populations. If there are testing, behavior, or spread differences between the two groups then bias would be introduced to over or underestimate vaccine effectiveness.
The studies in other countries are using test-negative case control methodologies that compare tested populations. That reduces the bias if for whatever reason people are less likely to be getting tested/infected due to factors besides the vaccine effectiveness.
So I think we should use the UK vaccine effectiveness data till proven otherwise. In the UK data, against symptomatic Covid the mRNA vaccines are ~88% effective and the AstraZeneca vaccine is ~67% effective after two doses. And against hospitalization, ~96% and ~92%.
