Vaccination and SARS-CoV-2 variants: how much containment is still needed? A quantitative assessment

TL;DR

This study uses a combined modeling approach to assess the ongoing need for containment measures during COVID-19 vaccination campaigns, emphasizing the importance of non-pharmaceutical interventions and strategic opening-closing policies.

Contribution

It introduces a novel integrated model combining epidemiological and economic projections to evaluate containment strategies amid emerging variants.

Findings

NPIs have greater impact than vaccination alone.

Intermittent opening and closing can reduce deaths and costs.

Maintaining containment measures is crucial during vaccination campaigns.

Abstract

Despite the progress in medical care, combined population-wide interventions (such as physical distancing, testing and contact tracing) are still crucial to manage the SARS-CoV-2 pandemic, aggravated by the emergence of new highly transmissible variants. We combine the compartmental SIDARTHE model, predicting the course of COVID-19 infections, with a new data-based model that projects new cases onto casualties and healthcare system costs. Based on the Italian case study, we outline several scenarios: mass vaccination campaigns with different paces, different transmission rates due to new variants, and different enforced countermeasures, including the alternation of opening and closure phases. Our results demonstrate that non-pharmaceutical interventions (NPIs) have a higher impact on the epidemic evolution than vaccination, which advocates for the need to keep containment measures in place throughout the vaccination campaign. We also show that, if intermittent open-close strategies are adopted, deaths and healthcare system costs can be drastically reduced, without any aggravation of socioeconomic losses, as long as one has the foresight to start with a closing phase rather than an opening one.