People walk past the US Treasury Department building in Washington, D.C., the United States, May 21, 2020. (Photo by Ting Shen/Xinhua)

The mortality rate among patients critically ill with COVID-19 in Wuhan, Central China's Hubei Province reached around 40 percent, respiratory expert Zhong Nanshan said at a biological products conference on Friday.

Over 80 percent of those who died from COVID-19 in China were aged above 60, and over 75 percent had at least one underlying disease, according to statistics released by China's Health Commission.

The numbers indicate that the pandemic in the US will get worse and deaths will increase if the country doesn't step up control measures, as it is seeing an increase in COVID-19 deaths, experts noted. Most of the deaths reported in the US are among elderly people who are more susceptible to the virus.

According to statistics released by the US Centers for Disease Control and Prevention, among the 231,197 deaths from COVID-19 from February 1 to November 14, 183,324 or 79.3 percent were people aged 65 and above. 

"For people at an advanced age, the risk of developing a severe COVID-19 infection and dying is higher, as they usually have some underlying diseases and relatively weak immunity to the virus," said Yang Zhanqiu, a professor at the pathogen biology department under Wuhan University.

Since there are currently no effective drugs to treat COVID-19, the US needs to apply stricter epidemic control policies to prevent more people from contracting the virus, Yang said, noting that wearing masks and controlling the flow of people as well as investing more in medical resources will be vital to combat the virus and reduce the mortality rate.

The US is now seeing more COVID-19 deaths as the coronavirus keeps spreading in the country. The number of fatalities in the US has seen a 42 percent increase in the last four weeks, rising from a weekly average of 821 per day in early October to last week's average of 1,167 per day, according to an NBC report on Thursday. 

As of 4:30 pm on Thursday US Eastern Time, the US reported over 11.66 million confirmed COVID-19 cases and 251,892 deaths, according to Johns Hopkins University, with more than 21.5 per 1,000 confirmed COVID-19 cases resulting in death.

The US CDC predicts that 276,000 to 298,000 COVID-19 deaths will be reported by December 12.

So far, plasma therapy treatment has also been relatively ineffective for severe cases, according to Zhong, who said that vaccines will be more important for elderly people.