**1. Introduction**

The COVID-19 pandemic is a social phenomenon; the first cases were identified in China in December 2019 and effected intense health, social, and demographic changes. The World Health Organization (WHO), on 30 December 2019, received a media statement by the Wuhan Municipal Health Commission regarding cases of 'viral pneumonia' in Wuhan, People's Republic of China, while on 30 January 2020, WHO announced a public warning regarding a health emergency of international concern [1]. Thus, on 11 February 2020, the "viral pneumonia" was named "COVID-19"

and on 29 February 2020, the first considerations were published for the quarantine of individuals in the context of containment measures for the coronavirus disease [2]. By 30 September 2020, 188 countries have reported as being affected by the coronavirus, with a global number of 34 million confirmed cases, and more than one million global deaths [3]. Currently, the most affected countries worldwide are the US, India, Brazil, Russia, Colombia, Peru, and Spain [3].

The Greek government, on 10 March 2020, in response to the preventive measures against COVID-19, imposed the closure of all educational institutions and, a few days later, the suspension of arts and sports events, while from 23 March to 4 May, a confinement measure was announced accompanied by strict bans for movement [4]. Generally speaking, the Greek authorities received affirmative comments for the decision to quickly enforce restrictive measures for limiting the spread of the disease in the country [5]. In spite of the aforementioned measures, by 30 September 2020, Greece counted 18,475 confirmed cases of COVID-19 and 391 deaths [3]. Additionally, based on the local situation, restrictions were imposed in certain regions [6].

While this life-threatening pandemic rapidly spreads around the world and causes millions of deaths and observed cases, WHO highlights the threat of "another dangerous virus" called an "infodemic" [7]. This term refers to the fake news and rumors in the context of the misinformation that feeds confusion against slowing the spread of disease [7]. With respect to this phenomenon, WHO states that reducing misconceptions and confusion about the virus and dealing effectively with the vast amount of valid and invalid coronavirus information is a matter of necessity [7] because "misinformation costs lives" [8]. There is evidence showing the strong positive correlation between knowledge and attitude [9], and in the case of the pandemic, the more knowledgeable the citizens are, the more positive attitude they hold toward COVID 19-related measures and recommendations for health behavioral changes as preventive strategies [10]. Indeed, knowledge is clearly stated by researchers as the key component of evidence-based practice, not only in the area of COVID-19 but also during their training as future health professionals [11,12].

According to Nutbeam (2000), health literacy is a combination of three different domains (functional, interactive, and critical) [13]. Having a poor literacy level leads to belief in myths, unreliable information, and fiction over facts. This behavior does not impact just the believers of these stories but also their close environment and entire society [14]. During the COVID-19 epidemic, several studies have focused on health literacy. However, it still remains an underestimated public health issue [10]. In a study conducted in Vietnam, medical students were less frightened due to health literacy [15]. Another study concluded that people with poor health literacy were likely to be more confused about COVID-19 information [8]. It is clear that an increase in the general population's knowledge and health literacy is of paramount significance for managing the epidemic and for controlling and preventing its spread [16].

Health professionals, education providers, and health science students have a key role in increasing the citizens' level of knowledge, the implementation of the pandemic measures, and compliance with them [17]. Due to the lack of healthcare personnel, in many countries, final-year medical and nursing students were invited to voluntarily join the frontline healthcare workforce in the COVID-19 battle, in order to enhance health sectors during this public health crisis. In any case, researchers claim that, even if medical students are not involved in clinical practice during the COVID-19 outbreak, they play a key role in serving as information providers [17]. Therefore, it is of major importance to avoid misconceptions and myths, identify students' possible knowledge gaps, encourage them as future health providers to search, critically appraise them, and adopt the new evidence in order to make informed decisions [8,18].

To our knowledge, no fully validated tool exploring nursing students' knowledge of and attitudes toward the COVID-19 public health crisis exists. Due to a shortage of appropriate research tools for answering this research question, we aimed to develop and validate a new instrument for the purpose of this study.
