These results suggest that SARS-CoV2 may be similar to the flu virus in one way: the asymptomatic rate. A study published in the journal Emerging Infectious Disease estimated that the asymptomatic rate for influenza to be 19.1% with a 95% confidence interval of 5.2% to 35.5%. So within the same ballpark, so to speak. Note that comparing the COVID-19 coronavirus to the flu in this way is no way saying that COVID-19 coronavirus is the same as the flu. This coronavirus is not just like the flu virus. This pandemic is different from the seasonal flu. SARS-CoV2 is not the flu. It just isn’t. Oh, and by the way, SARS-CoV2 is not the same as the flu.
This reported 15.5% to 20.2% range for SARS-CoV2 does overlap with the range provided by the second study that will be published as a research letter in the International Journal of Infectious Diseases. A pre-print proof version of the letter is available online. Presumably, there won’t be major changes in this paper once it becomes fully published. This study analyzed data on 565 Japanese nationals who had been evacuated from Wuhan, China. The research team which was primarily from Hokkaido University in Japan found that almost a third (30.8%) of those who had tested positive for SARS-CoV2 remained asymptomatic with a 95% confidence interval of 7.7% to 53.8%. The number is significantly higher but the 95% confidence interval is wider as well.