The new adjustments that China has made to its COVID-19 diagnosis and treatment protocols based on clinical evidence will be pivotal to the country's battle against the pandemic, said Zhang Wenhong, leader of the COVID-19 treatment expert team of Shanghai, on Thursday.

A pilot edition of the ninth COVID-19 diagnosis and treatment guidelines was released by the National Health Commission on Tuesday.

One of the major changes in the guidelines is the reduced isolation period for COVID-19 patients who have been discharged from the hospital, said Zhang, who is also head of the infectious disease department at Huashan Hospital in Shanghai.

Patients previously had to spend 14 days in a specific location after recovering. This has been changed to seven days of health monitoring at home.

"The general belief is that the longer the isolation period, the safer. But science has shown that once the viral load is lowered to a certain level, the disease is no longer contagious," said Zhang at a news briefing about Shanghai's COVID-19 response.

Another change is related to nucleic acid testing — the number of amplification cycles needed for a sample to be detectable has been reduced from 40 to 35.

"This will allow for shorter hospitalization periods for COVID-19 patients. The average length of hospitalization in Shanghai is currently 15 days, and with this change the duration can be reduced to 10 days," Zhang said.

"This will bring significant relief to quarantined patients and their families."

Zhang noted that the guidelines have also set standards for implementing triage procedures for patients in according to the severity of their condition. A stratified management system will also help optimize the use of medical sources.

"We have three weapons in our battle against the pandemic: Vaccination to its full extent, effective antiviral and other medicines, and enough medical resources at hand," he said.

"This renewed guideline is pivotal for our battle against the COVID-19, and we are looking forward to the implementation of these changes."

Authorities have said that the biggest COVID-19 surge in China in two years is primarily due to the highly transmissible subvariant of Omicron, known as BA.2.

More than 20,000 infections have been reported in Chinese mainland in this latest outbreak.