Dec 05, 2021

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Epidemiologists and virologists around the world agree that the mRNA vaccines have been proven vital around the world, and certainly in Israel where the third (booster) shot is available free to all citizens from the age of 12 – in saving lives from Coronavirus. 


While the vaccines are an essential component in the battle against the epidemic, it is clear that different contexts such as the characteristics of populations in each country and vaccine availability – together with the dynamic changes in disease spread – demand crucial decision-making on strategies and priorities 


Health officials and governmental leaders in every country in the world must make smart decisions about how to allocate vaccines and what sort of social distancing to mandate to combat the COVID-19 pandemic. Now, scientists at Ben-Gurion University of the Negev (BGU) in Beersheba have built a model that policymakers can use to simulate their choices and find the optimal one for their society.


Social distancing is an effective population-level mitigation strategy to prevent COVID19 propagation, the researcher wrote, “but it does not reduce the number of susceptible individuals and bears severe social consequences – a dire situation that can be overcome with the recently developed vaccines. Although a combination of these interventions should provide greater benefits than their isolated deployment, a mechanistic understanding of the interplay between them is missing.” 


To tackle this challenge, they “developed an age-structured deterministic model in which vaccines are deployed during the pandemic to individuals who do not show symptoms. The model allows for flexible and dynamic prioritization strategies with shifts between target groups. We find a strong interaction between social distancing and vaccination in their effect on the proportion of hospitalizations. In particular, prioritizing vaccines to elderly (60+) before adults (20 to 59) is more effective when social distancing is applied to adults or uniformly.”


The model “can tell you, for instance, whether it makes more sense to vaccinate the elderly and demand more social distancing from adults or vice versa,” said Dr. Shai Pilosof of BGU’s department of life sciences in the Faculty of Natural Sciences.


Their model was published recently in the peer-reviewed PLOS Computational Biology under the titleThe interplay between vaccination and social distancing strategies affects COVID19 population-level outcomes.” 


Some countries like Israel and the US have purchased ample supplies of vaccines, while others have only limited amounts. The new model can help calibrate vaccine deployment and social distancing. For example, according to their model, vaccinating the elderly and imposing social distancing mandates on adults is generally more effective than forcing the elderly to stay home and vaccinating the adults.


Prof. Nadav Davidovitch, director of BGU’s School of Public Health in the Faculty of Health Sciences and chairman of the Israel Public Health Physicians Association and a member of the Israeli National Expert Committee on COVID19, noted: “The current COVID-19 global situation demands a multilayered response. Our model can be applied by different countries to simulate and optimize responses.”