Actor Li Guangjie reads a letter for the show from home. [Photo provided to China Daily]

Unlike previous content, which were produced in a finely designed stage surrounded by an audience to re-create the scenes when the letters were written, the new episodes are all shot by the celebrities in their own homes.

Consecutively from 2017 to last year, the previous three seasons had respectively earned 8.9, 9.2 and 9.1 points on Douban, one of the country's most popular review sites.

Guan Zhengwen, the show's chief director, says the specially tailored season has selected the 15 letters from hundreds of letters and correspondence, as the crew wanted to comprehensively portray those people from different backgrounds who are battling the epidemic.

Upcoming episodes, which will be hosted by more stars, including actors Li Guangjie, Hai Yitian and singer Ji Jie, include letters conveying respect to a delivery man and a family's encouragement to a soldier who is dispatched to Wuhan.

One of the highlighted letters is written by Cai Yi, a doctor from the Central Hospital of Wuhan, to mourn a shopkeeper who died of novel coronavirus infection.

In Cai's letter, he recalls the shopkeeper Lin Jun－who had run a convenience store in the hospital for many years－as a nice and sincere person who likes to help others.

"We paid little attention to ordinary people like Lin in our daily lives. But we suddenly realized how important they were when they passed away," writes the emotional Cai.