The tiered restrictions enforced in November 2020 did not impact the epidemiology of the second wave of COVID-19 in Italy

Abstract

In the attempt to counter the second COVID-19 wave in autumn 2020, the Italian government introduced a unique countrywide system of physical distancing measures organized in progressively restrictive tiers (coded as yellow, orange, and red) imposed on a regional basis according to epidemiological risk assessments. This followed a set of other scattered or limited measures described in full detail by Manica et al. ¹.

This paper concerns the introduction of the tiered restrictions. The data used to evaluate the impact of the restriction system on SARS-CoV-2 transmissibility and hospitalization burden in Italy is from the Italian COVID-19 integrated surveillance system.

The reproduction number R(t) estimated on the onset of COViD-19 symptoms constantly decreased during most of the observation period 04 October 2020 - 06 December 2020 than is centered on the date of introduction of the measures and includes the expected latency to reach an effect. The fastest decrease of R(t) occurred in the period preceding the introduction of the tiered restrictions. There was no evidence that introducing the tiered restrictions determined the reduction of R(t). An alternative analysis using the daily growth rate of the epidemic curve confirms these conclusions. Similar considerations are made concerning the health system burden, analyzing hospitalizations at country level.

The trend of R(t) tending to increase shortly after the measures became effective does not allow to exclude that the enforcement of such restrictions might have been counterproductive.

These results are instrumental in informing public health efforts aimed at attempting to manage the epidemic efficiently. Planning further use of the tiered restrictions and the associated containment measures should be carefully and critically revised to avoid a useless burden to the population with no advantage for the containment of the epidemic or a possible worsening.