# Country-Based COVID-19 DNA Sequence Classification in Relation with International Travel Policy
## 1 Introduction  
Over three years, the COVID-19 global crisis has offered valuable lessons that can benefit humanity when facing similar disasters in the future [1]. The outbreak also indirectly highlights the varied responses and approaches adopted by different countries in managing the disease. Resulting proposed actions, such as the implementation of strict measures and financial support, notably proved effective in reducing infection and fatality rates [2]. Furthermore, a substantial amount of genomic data related to SARS-CoV-2, the virus causing COVID-19, has been systematically stored in popular databases. This wealth of information allowed scientists to extract insights and knowledge for effectively combating the pandemic. Utilizing this dataset, numerous studies have been conducted such as differentiating the DNA sequence of the COVID-19 virus from other diseases with similar symptoms [3, 4, 5] and classifying these sequences based on virus variants [6, 7]. By leveraging AI technology, these efforts can provide benefits for cost-effective disease detection. Initially, no significant mutations were observed in the COVID-19 virus during the first 8 months following the World Health Organization's declaration of it as a global threat [8]. However, a series of variants of concern gained prominence shortly thereafter, starting with the Alpha variant that emerged in September 2020 [9] and concluding with the Omicron variant, which became the predominant variant worldwide as of January 2022 [10]. Studies indicate that human migration (gene flow) plays a crucial role in virus evolution [11], allowing for the generation of many variations. The increased occurrence of distinct mutations in European, Asian, and North American sequences suggests thevirus's tendency to cluster geographically [12]. Moreover, analyzing the variations in the coronavirus genome among 10 countries, including the Czech Republic, France, Thailand, the USA, Japan, Taiwan, China, Australia, Greece, and India, concludes that the structure of the coronavirus genome significantly differs among countries [13]. In a specific area, a genome-wide analysis of circulating SARS-CoV-2 strains has been conducted to identify the emergence of novel co-existing mutations and trace their geographical distribution within India [14]. Thus, the genetic variances observed among the strains from diverse locations can be linked to their geographical distributions. When considering the impact of the COVID-19 outbreak, a comprehensive analysis of the SARS-CoV-2 genome sequences isolated from individuals in six geographic areas reveals correlations with fatality rates in various countries [15]. This correlation is also supported by studies indicating a positive connection between the occurrence of specific gateway mutations and mortality [16; 17]. Conversely, some studies suggest no association between SARS-CoV-2 variants and mortality rates [18; 19; 20]. Nevertheless, the diverse structure of the coronavirus genome among countries is a critical aspect that requires investigation for vaccine development [13]. In addition to extensive work in phylogenetic-based approaches, which includes a specific profiling method for DNA sequences aimed at the accurate analysis of SARS-CoV-2 genomes at the genus or species levels [21], it is equally important to explore country-based classifications of sequences. To the best of our knowledge, no existing literature has explicitly conducted a classification of DNA sequences based on the country where they come from. While we cannot ignore the fact that each country has varying land areas that may influence the level of virus variation in each region, recognizing the distinction of DNA sequences, a pivotal component in the genomic data, based on the country of origin could potentially deepen our understanding of how the virus evolves within the area.