Two suburban districts in Shanghai achieved the dynamic zero-COVID goal on Wednesday amid the declining trend of the city's COVID-19 resurgence, the Shanghai Health Commission said.

Jinshan and Chongming districts hit the target on a community level, said Wu Qianyu, a senior health commission official. The target means the resurgence is under control without any community transmissions.

According to the districts' official WeChat accounts, Jinshan reported seven new positive cases on Wednesday, and Chongming Island reported 75.

"Citywide, the community spread has been effectively curbed," Wu said at the city's daily COVID-19 press briefing. She added that the number of new cases has been declining for three consecutive days in subdistricts and towns that report more than 100 daily new cases.

The city reported 2,494 local COVID-19 cases and 16,407 asymptomatic infections on Tuesday, including 533 confirmed patients who were previously asymptomatic, according to Wu.

That number is 5 percent less than Monday and 14 percent lower than Sunday.

Meanwhile, a total of 27,093 COVID-19 patients were discharged from local designated or makeshift hospitals on Tuesday, a 16 percent increase over the previous day.

The number of cases has been trending downward over the past three days in the Pudong New Area, Minhang, Songjiang, Qingpu and Putuo districts, while conditions in Xuhui, Yangpu, Hongkou, Changning and Baoshan districts continue to slightly fluctuate, Wu said.

The situation in Huangpu District is still trending upward, while the number of new cases in Jing'an District is rising slowly. Infections in Fengxian, Jinshan and Chongming districts remain at a low level, according to Wu.

However, Shanghai reported seven new deaths among its COVID-19 patients on Tuesday, bringing the total since the resurgence in March to 17.

The seven deaths, including two under the age of 60 and five older than 70, died of severe underlying diseases, such as cancer, heart disease, severe hypertension and brain infarction. Two of them had been vaccinated.

A complete COVID-19 vaccine regimen can reduce severe symptoms and death for elderly people by 70 percent, while booster shots can further reduce the risks by 90 percent, said Sun Xiaodong, deputy director of the Shanghai Center for Disease Control and Prevention.

Among Shanghai's COVID-19 patients, 19 percent are over the age of 60 and 2 percent are older than 80, Sun said.

"The elderly are surely a vulnerable group," Sun said. Once infected, they are likely to infect others, such as family members and caretakers.

He beckoned unvaccinated seniors to get fully vaccinated after the lockdown is lifted.

To promote COVID-19 prevention and control knowledge among the elderly, Shanghai Health Promotion Office has issued special posts with tips on self protection, disinfection, nutrition, exercises, health management and vaccination, officials said.

Shanghai launched a new round of PCR testing and antigen self-testing this week.

The list of the city's locked-down, controlled and precautionary areas has been updated based on results of the latest screenings, Wu said.

The number of residents in newly designated locked-down areas, where positive cases have been reported within the past week, has been reduced by more than 4 million.

The number of people in precautionary areas – where no positive case has been detected in the past week – has increased by more than 2 million.

"Shanghai's pandemic prevention situation remains difficult and complicated," Wu said.

She asked those in precautionary areas – who are permitted to move around within their subdistricts or towns – to minimize travel, avoid gatherings, maintain social distance and protect themselves.