Non-pharmaceutical interventions during the COVID-19 pandemic: A review

Abstract

Infectious diseases and human behavior are intertwined. On one side, our movements and interactions are the engines of transmission. On the other, the unfolding of viruses might induce changes to our daily activities. While intuitive, our understanding of such feedback loop is still limited. Before COVID-19 the literature on the subject was mainly theoretical and largely missed validation. The main issue was the lack of empirical data capturing behavioral change induced by diseases. Things have dramatically changed in 2020. Non-pharmaceutical interventions (NPIs) have been the key weapon against the SARS-CoV-2 virus and affected virtually any societal process. Travel bans, events cancellation, social distancing, curfews, and lockdowns have become unfortunately very familiar. The scale of the emergency, the ease of survey as well as crowdsourcing deployment guaranteed by the latest technology, several Data for Good programs developed by tech giants, major mobile phone providers, and other companies have allowed unprecedented access to data describing behavioral changes induced by the pandemic. Here, I review some of the vast literature written on the subject of NPIs during the COVID-19 pandemic. In doing so, I analyze 348 articles written by more than 2518 authors in the first 12 months of the emergency. While the large majority of the sample was obtained by querying PubMed, it includes also a hand-curated list. Considering the focus, and methodology I have classified the sample into seven main categories: epidemic models, surveys, comments/perspectives, papers aiming to quantify the effects of NPIs, reviews, articles using data proxies to measure NPIs, and publicly available datasets describing NPIs. I summarize the methodology, data used, findings of the articles in each category and provide an outlook highlighting future challenges as well as opportunities.

Keywords: Behavioral changes; COVID-19; Non-pharmaceutical interventions; SARS-CoV-2.

Fig. 1

Schematic representation of the classification scheme. The central node describes all articles. The size of each node (i.e., category) is proportional to the number of articles.

Fig. 2

Total number of authors and citations of the papers in this category on the left. Note that these numbers are estimated from Semantic Scholar. On the right (top) histogram describing the number of countries subject of study in this category. Note how few papers that studied hundreds of countries are not counted in the histogram. On the right (bottom) most represented publication venues of the category. To improve visibility I am showing only journals featuring at least two articles.

Fig. 3

Total number of articles, sub-categories, authors, and citations of the papers in this category on the left. Note that these numbers are estimated from Semantic Scholar. On the right (main panel) histogram describing the number of countries subject of study in this category. On the right (in-set) most represented publication venues of the category. To improve visibility I am showing only countries featured at least in two studied and journals featuring at least two articles.

Fig. 4

Total number of authors and citations of the papers in this category on the left. Note that these numbers are estimated from Semantic Scholar. On the right histogram describing the number of countries considering authors’ affiliations.

Fig. 5

Total number of authors and citations of the papers in this category on the left. Note that these numbers are estimated from Semantic Scholar. On the right (top) histogram describing the number of countries subject of study in this category. Note how I have removed from the count, few papers that studied hundreds of countries as I could not find machine readable lists. On the right (bottom) most represented publication venues of the category. To improve visibility I am showing only journals featuring at least two articles.

Fig. 6

Total number of authors and citations of the papers in this category on the left. Note that these numbers are estimated from Semantic Scholar. On the right histogram describing the number of countries representing authors’ affiliations.

Fig. 7

Total number of authors and citations of the papers in this category on the left. Note that these numbers are estimated from Semantic Scholar. On the right (top) histogram describing the number of countries subject of study in this category. Note how few papers using data from hundreds of countries are not counted in the histogram. On the right (bottom) most represented publication venues of the category.

Fig. 8

Total number of authors and citations of the papers in this category on the left. Note that these numbers are estimated from Semantic Scholar. On the right (top) histogram describing the number of countries describing authors’ affiliations. On the right (bottom) most represented publication venues of the category.