In the pace of global vaccination, Israel leads the way. Up to now, nearly 80% of Israeli adults have completed the vaccination, and the country has not yet carried out vaccination work for children and adolescents under 16 years of age. While the outside world is discussing whether Israel has completed herd immunity, a domestic study pointed out that Israel’s high coverage of the new crown vaccine is related to the low infection rate of the new crown virus (SARS-CoV-2) in people aged 16 and under. June 10, local time, international academic journal “Nature Medicine” (Nature Medicine) published this article online, entitled “Community-level evidence for SARS-CoV-2 vaccine protection of unvaccinated individuals”. The results of the study come from the researchers’ analysis of vaccination records and test results in 177 communities in different geographic locations in Israel from December 6, 2020 to March 9, 2021.
The research team has shown that COVID-19 vaccination can not only protect those who have been vaccinated, but also those who have not been vaccinated. The corresponding authors of the study are Tal Patalon of Maccabitech, the R&D and Innovation Department of the Israeli Health Organization, and Roy Kishony of the Technion-Israel Institute of Technology.
The study mentioned that previous clinical trials and vaccination plans show that Pfizer-BioNTech’s COVID-19 vaccine is effective in preventing infection and disease at the individual and community levels . However, studies have also shown that vaccination may cause changes in human behavior and increase infectivity. For example, people who have been vaccinated may not pay much attention to maintaining social distancing or not actively isolate themselves after contact with COVID-19 patients.
Israel began vaccinating on December 19, 2020, and covered nearly 50% of the population within 9 weeks. In order to determine whether vaccination can reduce the spread of SARS-CoV-2 among unvaccinated individuals at the group level, Kishony et al. studied 177 geographical locations with different vaccination rates (a total of 1.37 million people received the first dose) Communities, and a group of unvaccinated groups under 16 years of age who have no vaccine yet. They counted the changes in the number of COVID-19 positives in each community at regular intervals.
They found that, on average, for every 20% increase in the number of vaccinated people in a community, the number of SARS-CoV-2 positive people in the same community who have not been vaccinated would roughly double.The research reminded that their research results did not take into account the population’s exposure to SARS-CoV-2 Acquired natural immunity. They finally said that although it is exciting to see vaccine-related protection in unvaccinated people, further research is still needed to understand how vaccination programs can help achieve herd immunity and eliminate diseases.
Link to the paper: https://www.nature.com/articles/s41591-021-01407-5