**1. Introduction**

Since the first outbreak of COVID-19 in December 2019 [1], there are now (7 May 2020) approximately 3,871,312 infected and 272,856 deaths as a result of the COVID-19 pandemic [2]. The rapid spread of COVID-19 around the world has caused serious damage to each nation, including fatal risks, unemployment, and deteriorating work–life balance [3–5]. Accordingly, a state of emergency was declared worldwide because of COVID-19, and efforts are being exerted to overcome the current situation [6]. This includes nurses taking care of COVID-19 patients at the scenes of COVID-19 infections, where they have to wear protective equipment for many hours, leaving marks on their faces [7]. However, as COVID-19 has been ongoing for a long time, nurses are facing hardships in carrying out their jobs [8,9]. In every country, nurses are being praised for their efforts, and countless encouraging messages are relayed to medical workers through mass media. For example, Banksy, an anonymous England-based street artist, sent a painting to Southampton General Hospital that memorialized nurses as children's heroes [10]. In addition, people are spreading encouraging dance challenge videos with the theme of "support for the nurses" through social networking services' platforms [11]. These efforts recognize that nurses are the most directly exposed to COVID-19 and that their work has increased dramatically during the pandemic; in so doing, they bring greater awareness to the situation, and nurses around the world have praised these efforts [12].

This social support (i.e., encouragemen<sup>t</sup> sent to nurses) is possible because many people can relate to the sacrifices and service of the nurses in the COVID-19 pandemic despite the risks. Social support has a positive effect on subjects' mental health; in particular, it influences job-related stress reduction and can even enhance self-esteem [13]. In addition, as technology develops, social knowledge is being created through the means of social networks [14].

In a study by Lee and Yoon [15], it was found that nurses who received social support had reduced depression and high self-resilience. Furthermore, social support reduces nurses' emotional labor and burnout [16]. Since the COVID-19 situation absolutely requires the staffing of nurses, it is imperative to study the effectiveness of nurses' current social support. Social support is conceptually defined as providing individuals with resources in either tangible or intangible forms, which are typically divided into the categories of emotional, instrumental, or informational support, and appraisal [17]. Additionally, social support is characterized by mutuality, that is, an exchange in resources between individuals or between an individual and a group. Sullivan [18] stated that people want to have positive relationships with others and feel accepted, so efforts are made for social interaction. Social support appears differently as individuals face more difficult situations. Krause [19] stated that in this sense, social support could be harmful, although most cases of social support are considered positive. For example, social support can have positive effects such as reducing stress and improving self-esteem, but alcohol consumption and stress may increase [20,21]. Precedent studies conducted on social support show that it was used as a measure of social resources to control the stress that results from the working environment [22,23]. Munro's research [24], which targeted 60 Australian nurses, showed that social support has a negative relationship with initial stress. Moreover, Lee Young Mi [15] stated that nurses' social support appears differently depending on general characteristics, and job satisfaction is higher when social support is recognized. Recent studies show that social workers' turnover is positively affected by social support [25], and a study of nurses said that social support helps them cope with the working environment and thrive [13].

Therefore, it is necessary to investigate how social support influences job retention for nurses who are managing duties that are more difficult than usual in the pandemic situation. However, according to research results related to nurses in the context of the COVID-19 epidemic, the nurses' working environment is dangerous and more exhausting than usual [26–28]. A study by Maben and Bridges [29] suggested that nurses need psychological and mental health support. In addition, only studies about the high job stress of nurses in pandemic outbreak situations and turnover intention are in progress [30,31], and there is insufficient practical research into how social support recognized by nurses is connected to job retention. In response, this study aims to investigate how social support affects job engagemen<sup>t</sup> and how the job retention intention of nurses is affected by social support in the continuing COVID-19 situation.

#### **2. Materials and Methods**
