Sharjah24 - Reuters: China's tough zero-COVID measures remain essential to defeat the pandemic and buy time to improve vaccination rates and develop new treatments, senior health advisers wrote in recently published reports.

Shanghai, a city of 25 million people, has been locked down for nearly six weeks as it battles China's biggest coronavirus outbreak, but the government have shrugged off criticism of its zero-COVID strategy, saying it remains the best option.

In correspondence published by the peer-reviewed medical journal the Lancet last Friday, a team of city medical experts said Shanghai's vital role in the national economy made lockdown unavoidable.

"As a leading economic centre and an open city in China, Shanghai has huge exchanges with other cities and regions in the country, so the spill-out of virus to other places... could have unimaginably severe consequences," said the team, which includes Zhang Wenhong, an adviser to authorities in Shanghai on treatment for COVID-19.

Shanghai's "dynamic" zero-COVID policies would "overcome weak links in the immunological barrier in populations across the country", they said, pointing out that around 49 million people aged 60 and over were still unvaccinated.