First indication of the effect of COVID-19 vaccinations on the course of the outbreak in Israel

Concomitantly with rolling out its rapid COVID-19 vaccine program, Israel is experiencing its third, and so far largest, surge in morbidity. We aimed to estimate whether the high vaccine coverage among individuals aged over 60 years old creates an observable change in disease dynamics. Using observed and simulated data, we suggest that the shape of the outbreak as measured by daily new moderate and severe cases, and in particular of patients aged over 60, has changed because of vaccination, bringing the decline in new moderate and severe cases earlier than expected, by about a week. Our analyses is consistent with the assumption that vaccination lead to higher than 50% protection in preventing clinical disease and with at least some effectiveness in blocking transmission of elderly population, and supports the importance of prioritizing vulnerable population. This is the first indication of the effectivity of COVID-19 vaccine in changing the course of an ongoing pandemic outbreak. One Sentence Summary We show, by data analysis and modelling of the dynamics of COVID-19 pandemic in Israel, that the current nationwide outbreak, that had up to 0.1% of the population confirmed daily, is clearly affected by the vaccination program, that reached a coverage of more than 80% among people ≥ 60 years old. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement No external funding was received ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study protocol was approved by the Institutional Review Board (Helsinki Committee) of Hadassah Medical Center. Study was exempted from informed consent based on anonymity of participants (anonymization carried out by the Ministry of Health) and aggregated data analysis. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The data that support the findings of this study are available from the corresponding author upon reasonable request: * Most of the data is available on * Daily moderate and severe cases by age groups were obtained from the Ministry of Health. Data provided by the Ministry of Health was available through the Ministry's research room, accessible only to authorized researchers (Ronit Calderon-Margalit). Data was then aggregated by age and analyzed in two age groups and without any identifiers. [https://www.rki.de/DE/Content/Infekt/EpidBull/Archiv/2020/Ausgaben/17\_20.pdf%20?\__blob=publicationFile][1] [1]: https://www.rki.de/DE/Content/Infekt/EpidBull/Archiv/2020/Ausgaben/17_20.pdf%20?__blob=publicationFile