Is COVID-19 Herd Immunity Influenced by Population Densities of Cities?

The objective of the current study is to compare between densely and sparsely populated cities in the context of herd immunity against the SARS-CoV-2 virus. The sample refers to 46 (45) densely populated (sparsely populated) Israeli cities and towns, whose population density is below (above) the median of 2388 personssq.km, covering above 64.3% of the entire Israeli population. Findings suggest, on the one hand, a higher projected scope of morbidity per 10,000 persons in sparsely populated cities with zero prevalence of vaccination (37.79 vs. 17.61 cases per 10,000 persons). On the other hand, the outcomes propose a steeper drop in the scope of COVID-19 morbidity with higher vaccination rates in sparsely populated cities. Findings suggest that in terms of vaccination campaigns, below 60–70 percent vaccination rates, more efforts should be invested in sparsely populated cities. If, however, the 70 percent threshold is achieved, a further reduction in the scope of morbidity would require a higher (lower) rate of vaccination in densely populated (sparsely populated) cities.