Hundreds of Shanghai's top medical experts have joined in the treatment of COVID-19 patients with severe symptoms to curb the growing rate of deaths among  local infections, which has reached 87.

More than 360 experienced medical experts specializing in severe disease symptoms along with experts from outside Shanghai have rushed to the city's eight city-level COVID-19 designated hospitals, where most patients in serious conditions are being treated.

The experts in nine teams will focus on the patients' severe underlying diseases, which have become the main cause of the city's COVID-19 death cases, said Wang Xingpeng, director of Shanghai Shenkang Hospital Development Center.

Shanghai reported 39 COVID-19 deaths on Saturday, bringing the total since the resurgence in March to 87.

The fatalities include 48 male patients and 39 females with an average age of 81. The oldest was aged 101. All of them had severe underlying health conditions, such as advanced tumor, heart disease, brain infarction, liver cirrhosis, diabetes and uremia. Only five had been vaccinated.

"People in advanced ages are the most vulnerable to coronavirus due to low immunity and weak physical conditions," said Zhao Dandan, deputy director of Shanghai Health Commission.

He said the city will try its best to reduce the death rate among COVID-19 infections with the early intervention of medical experts, application of traditional Chinese medicines and a push for vaccination among eligible seniors.

Among Shanghai's COVID-19 patients, 160 have severe symptoms and 19 are in critical conditions.

Nearly a third of the COVID-19 patients at the city-level designated hospitals are over 70, according Wang.

Among them, over 60 percent suffer from one or several underlying diseases, mainly heart, kidney, respiratory and nervous systems and cancer, so only a small group have been vaccinated, he added.

Another 53 local medical experts in 15 specialties are hosting daily online consultations to make and adjust customized treatment plans for each patient in severe conditions.

Meanwhile, more than 300 medical experts in eight treatment teams are based at the district-level designated hospitals and makeshift hospitals.

Patients who develop severe symptoms will be transferred to the city-level designated hospitals.