Firstly, I want to address ‘we’ as every human being on Earth for the sake of public health regardless of their geographical or social position. Hence, this blog would be written for the case of only one individual making a decision whether they should be worried about COVID-19 or not. Secondly, although there are multiple factors – sometimes misinformation making us worried, it is the actual impacts on one’s well-being of COVID-19 that make one worry. Accordingly, this blog attempts to assess the risks of COVID-19 using the evaluation of the Influenza Risk Assessment Tool (IRAT) developed by the U.S. Central for Disease Control (CDC) which suggests that risk proposed by a novel virus involves two scenarios: (1) emergence – the ability of transmission of the virus and (2) public health impact – its clinical severity and social burden (CDC, 2020).
The transmissibility of a virus is determined by its reproduction number, R, the quantity of people who would catch the virus from 1 infector. For a virus to achieve sustained transmission, R must be greater than 1; so, if R is less than 1, the chance of chained transmission would be the least. In the case of COVID-19, an R of 2.2 has been reported (Li Q et al., 2020, as cited in Thompson, 2020). This number suggests that to keep R less than 1, we need to prevent over half of COVID-19 infections (Thompson, 2020). This would be challenging if only COVID-19 could cause presymptomatic transmission, which is not the case of COVID-19 (Kupferschmidt, 2020). Hence, isolating symptomatic infectors – which is already done, is enough to keep transmission level of COVID-19 low, thereby making the potentials of becoming a global pandemic of COVID-19 is low. However, in the situation report on February 10th, WHO has warned high risk level in regional and global scale.  
Regarding clinical severity, beside mild symptoms, COVID-19 can lead to fatality (WHO, 2020). Although WHO has announced the mortality rate of COVID-19 is 2% on January 29th, 2020 (WHO, cited in Worldometer, 2020); this organization also warns that it is still too early to have an exact number. Another study of Chen Wang and colleagues claims that the overall case ratio is 3% and it is likely to decrease (Wang, Horby, Hayden & Gao, 2020). Comparing to that of SARS – 9.6% and MERS – 34%, COVID-19 either with 2% or 3% of case fatality is considered low-risk (Worldometer, 2020).
In term of burden on society, COVID-19 has tremendously impacted global economy. Despite the early time and unstable numbers, McKibbin estimated that COVID-19 would cause a loss of 160$ to global economic growth, 4 times that of SARS in 2003 (cited in Bloomberg, 2020).  Factually speaking, COVID-19 has caused a pause on school in all over Vietnam – which can also be seen as social burden.
So, should we be worried with its currently low mortality rate, manageable transmissibility, and huge economic loss? Still, it is too early to tell.

LIST OF REFERENCES
Coronavirus Mortality Rate (COVID-19) - Worldometer. (2020). Retrieved 13 February 2020, from https://www.worldometers.info/coronavirus/coronavirus-death-rate/#nhc
Influenza Risk Assessment Tool (IRAT) | Pandemic Influenza (Flu) | CDC. (2020). Retrieved 11 February 2020, from https://www.cdc.gov/flu/pandemic-resources/national-strategy/risk-assessment.htm
Li Q Guan X Wu P et al. Early transmission dynamics in Wuhan, China, of novel coronavirus-infected pneumonia. N Engl J Med. 2020; (published online Jan 29.) DOI:10.1056/NEJMoa2001316
M. McKibbin , cited in Daurat, C. (2020). Bloomberg. Retrieved 11 February 2020, from https://www.bloomberg.com/news/articles/2020-01-31/the-global-economy-is-getting-infected-by-the-virus
Thompson, R. (2020). Pandemic potential of 2019-COVID-19. The Lancet Infectious Diseases. doi: 10.1016/s1473-3099(20)30068-2
Wang, C., Horby, P., Hayden, F., & Gao, G. (2020). A novel coronavirus outbreak of global health concern. The Lancet. doi: 10.1016/s0140-6736(20)30185-9
WHO. (2020). Corona Virus. Retrieved 11 February 2020, from https://www.who.int/emergencies/diseases/novel-coronavirus-2019