**1. Introduction**

The level of digital and physical connectedness of today's societies has never been seen before. We are able to see and talk to people on the other side of the planet as if they are with us. We are able to control machines in the farthest continents using our smartphones. We are able to physically travel across the world in a day. We travel a lot to distant lands and frequently share gifts and viruses with each other.

Unfortunately, the COVID-19 pandemic has exposed the vulnerabilities of this unprecedentedly connected world. The COVID-19 pandemic, or coronavirus pandemic (COVID-19 is the name of the disease), is caused by the virus SARS-CoV-2 (Severe Acute

**Citation:** Alomari, E.; Katib, I.; Albeshri, A.; Mehmood, R. COVID-19: Detecting Government Pandemic Measures and Public Concerns from Twitter Arabic Data Using Distributed Machine Learning. *Int. J. Environ. Res. Public Health* **2021**, *18*, 282. https://doi. org/10.3390/ijerph18010282

Received: 22 November 2020 Accepted: 28 December 2020 Published: 1 January 2021

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Respiratory Syndrome CoronaVirus 2) [1]. As of 19 November 2020, over 56 million people have been infected with nearly 1.35 million deaths, and the numbers are growing [1]. Social, economic, and environmental sustainability has been severely affected throughout the world. There is a growing consensus that the post-pandemic societies and world may take a different course for living, work, education, and other spheres of life. If (partial or full) remote working, businesses, and education are to become the norm, many people may choose to move and live in suburban or rural areas, and this will shift the course of urbanization.

There is a need to understand what is happening around the world during and after the pandemic, what measures are being taken to fight the pandemic by the government and authorities, what the needs of the people are, and what people's concerns and priorities are, etc. This information can help us to understand the implications of various pandemic measures (e.g., social isolation), manage the pandemic, address people's concerns, understand the impact of various policies for the post-pandemic future, and more.

Traditional methods of data collection and analysis using surveys and other means cannot capture such timely and large-scale data, alongside them having other disadvantages. Researchers in recent years have increasingly used social media including Twitter to study different issues in many application domains and sectors [2–5]. Naturally, social media has also been used during the COVID-19 pandemic times even more so, because the use of social media and virtual platforms by the public has increased due to social isolation and reduced mobility. A detailed literature review has revealed that the state-of-the-art research on social media analytics for COVID-19-related studies is limited. Many more studies are needed to improve the breadth and depth of the research on the subject in several aspects (Section 2 elaborates the research gap, novelty, and contributions of our work).
