Green Pass and COVID-19 Vaccine Booster Shots in Israel – A More ‘Realistic’ Empirical Assessment Analyzing the National Airport Data

November, 2021

Abstract

The paper describes an analysis based on data published on November 1, 2021, by the Israeli Ministry of Health (MOH) on its control dashboard about returning Israelis through the national airport. The data include the respective numbers of Vaccinated and Unvaccinated individuals and the number of positive COVID-19 cases identified in each group. These reflect the modified definitions of Vaccinated and Unvaccinated status after the Pfizer booster vaccination campaign in Israel (August-October). In particular, to maintain a Vaccinated status and specifically the “Green Pass”, individuals who received the initial 2 doses more than 6 months ago were required to receive the booster vaccine.

Israel national airport is a unique setting, where the Vaccinated and Unvaccinated individuals all have to test, which allows a more objective assessment of both the booster and Green Pass efficacy in preventing infections. The analysis suggests that the positivity rate (number of cases divided by number of tests) among the Vaccinated cohort throughout August-October is only 1.54-fold smaller than the one among the Unvaccinated cohort (about 35% relative protection). More specifically, compared to the Unvaccinated group, the Vaccinated group has a significantly higher positivity rate during the month of August, then in September it shows a 3.45-fold smaller positivity rate (71% relative protection), and this protection decreases to 2.66-fold (62% protection) during October. The analysis suggests that the relative protection of the booster shot against infection is likely to be significantly smaller than the initial estimates of 10-11-fold (over 90%) reported by the MOH, probably around 60% at best. This also implies that the absolute number of infected individuals in the Vaccinated group is likely to be at least as high as in the Unvaccinated, raising serious concerns that the new Green Pass is inefficient in preventing infection spread, and could expose high risk individuals to risk.