China’s nasal-spray Covid-19 vaccines undergoing clinical trials:

Researchers are conducting phase-1 and phase-2 clinical trials on a China-made inhaled Covid-19 vaccine, a Chinese health official said Friday.

After completing the collection of clinical-trial data, experts will study the safety and effectiveness of the inhaled vaccine, a modified version of an injectable adenovirus vector COVID-19 vaccine that has already hit the market, said Shao Yiming, a researcher at the Chinese Center for Disease Control and Prevention, at a press conference.

The inhaled Covid-19 vaccine was jointly-developed by researchers from the Institute of Military Medicine under the Academy of Military Sciences and China’s CanSino Biologics Inc.

Inhaled or nasal-spray vaccines were selected as one of China’s vaccine technologies to combat Covid-19 from the very beginning, Shao added.

Another nasal-spray Covid-19 vaccine, developed by Xiamen University, the University of Hong Kong and Beijing Wantai Biological Pharmacy, has completed phase-1 and phase-2 trials. Researchers are applying phase-3 clinical trials overseas, to further evaluate the efficacy of the vaccine.

The company’s co-founder and Chief Executive Xuefeng Yu said in an interview that theoretically, an inhaled vaccine could provide additional protection by activating antibodies or T cells — white blood cells that are vital to the immune system — in the airways.

If that protection layer fails and the virus travels deeper into the body, other parts of the immune system could still fight the Covid virus, added Yu.

Efficacy rates for China’s Covid vaccines have been found to be lower than those developed by Pfizer-BioNTech and Moderna. Earlier this month, the director of the Chinese Center for Disease Control publicly acknowledged that Chinese vaccines “don’t have very high protection rates” and that they were considering giving people different Covid shots to boost vaccine efficacy.

Yu added that an inhaled vaccine could be more effective than those injected given that the coronavirus enters the human body through the airways.