BEIJING, Jan. 26 -- Momentum of the epidemic outbreak may decline in 20 days based on the current prevention and control measures of pneumonia caused by the novel coronavirus (2019-nCoV), a leading virologist said Sunday.

The increase of confirmed cases recently resulted from people infected with the virus about 20 days ago, said Wen Yumei, an academician of the Chinese Academy of Engineering, adding that the current measures are expected to prevent future infection.

The human body will gradually become immune to the microorganism, which may drive an end to the epidemic, said Wen, also a professor at a key lab on medical molecular virology in Shanghai.

Noting most patients that are in critical condition have other existing diseases with immune system disorders, Wen said the public does not need to panic, as a large number of those infected will recover with the help of their immune system.

However, effective self-protection measures like wearing masks are needed, as the epidemic is infectious without typical symptoms during the incubation period, said Cao Wei, deputy director with the infection department at the Peking Union Medical College Hospital.