SHANGHAI, March 17 (Xinhua) -- An mRNA vaccine for COVID-19 is expected to enter clinical trials in mid-April, a health official in Shanghai was quoted by Tuesday's Science and Technology Daily as saying.

Virus-like particle (VLP) vaccines have produced specific antibodies in mouse immune experiments, Yi Chengdong, deputy director of Shanghai Municipal Health Commission, told a press conference Monday. The vaccine toxicity studies have been carried out on primate animals, according to the report.

VLP vaccines are multiprotein structures that mimic the organization and conformation of viruses but lack the viral genome, potentially yielding effective, safer and affordable vaccine candidates.

Meanwhile, three novel coronavirus test products have been approved and clinically applied in Shanghai, said Zhang Quan, director of Shanghai's science and technology commission.

"As of March 15, more than 80,000 test reagents from Shanghai had been exported to 22 countries including Germany, Japan, the Republic of Korea and Saudi Arabia," Zhang was quoted by the paper as saying.