In this May 28, 2021 file photo, a healthcare worker prepares a dose of the Sinovac COVID-19 vaccine during a vaccination session for medical staff who work at private clinics in Caracas, Venezuela. (MATIAS DELACROIX / AP)

BEIJING - China has witnessed 21 COVID-19 vaccines enter clinical trials, an official with the National Health Commission said Sunday.

So far, four COVID-19 vaccines have been granted conditional marketing approval and three have been authorized for emergency use within the country, according to Zeng Yixin, deputy head of the NHC.

The clinical trials of China-developed nasal spray and inhaled COVID-19 vaccines are also currently underway

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A total of eight COVID-19 vaccines have been approved for phase III clinical trial overseas, and one messenger RNA (mRNA) COVID-19 vaccine met the ethical requirements for phase III clinical trial overseas, Zeng said.

He also said the clinical trials of China-developed nasal spray and inhaled COVID-19 vaccines are currently underway.

The nasal spray has been selected as one of China's vaccine technologies to combat COVID-19 in the very beginning, Zeng said.

Medical experts will study the safety and effectiveness of the tested vaccines after completing the collection of clinical trial data, he added. 

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