The vaccine was designed as a nasal spray because the virus usually enters the body through the upper respiratory tracts. Photo: Xiamen University

A nasal-spray Covid-19 vaccine, jointly developed by the University of Hong Kong and Xiamen University, will have phase-1 clinical trials in November in Hong Kong.

About 100 volunteers will be recruited for trials of the vaccine, Yuen Kwok-yung, head of the Department of Microbiology at the University of Hong Kong, said Thursday. The Food and Health Bureau has granted a HK$20 million (US$2.58 million) to buy insurance for the participants, Yuen said.

The phase-1 trials would be completed within two months. More than 10,000 people would take part in phase-2 and 3 trials. It would take at least a year for the vaccine to be launched for sale, he said.

Yuen said the vaccine was designed as a nasal spray instead of an injection because the virus usually enters human bodies through the upper respiratory tracts.

Currently, three types of vaccine are under phase-3 trials and are expected to be ready for sale in mainland China by the end of this year. Two have been developed by China National Pharmaceutical Group and the other is owned by Sinovac Biotech.

The vaccine developed by the University of Hong Kong and Xiamen University will be manufactured by the Beijing-based Wantai BioPharm. In 2005, Wantai and Xiamen University jointly set up the National Institute of Diagnostics and Vaccine Development in Infectious Diseases to commercialize the university’s biomedical research projects.

Research and development of the vaccine were co-led by Xia Ning-shao, Dean of Xiamen University’s School of Public Health, and Chen Honglin, a professor at the Department of Microbiology, the University of Hong Kong’s Li Ka Shing Faculty of Medicine.

Graduating from Xiamen University in 1986, Chen studied for a doctoral degree at the University of Hong Kong with a scholarship granted by the Li Ka Shing Foundation.

Last month, Xia said in an interview with Chinese Health, a magazine published by China’s National Health Commission, that vaccines would be the final weapon for the world to fight the pandemic as the economic costs of social distancing were very high.

Xia said any vaccine had to be proven safe and reliable before it was launched for public use. He said researchers had to find out the vaccine’s effects and side-effects and its sustainability and whether it would have an “antibody-dependent enhancement” effect that helps virus grow or lose its effect against mutated viruses.

On Wednesday, an official from the Fujian provincial government told mainland media that the government had granted 3 million yuan (US$438,751) to Xia’s team this year for the research and development of the vaccine.

Xia’s team also received 4 million yuan of research funds from the central government. The official said the nasal-spray vaccine had recently gained approval from the National Medical Products Administration to begin phase-1 trial, which had started in Dongtai, Jiangsu province, on September 1.

According to previous tests, it was found that hACE2 transgenic mice and hamsters suffered from less lung damage with the vaccine than those without when they were infected with the coronavirus.

Yuen said it was normal that clinical trials of the vaccine would start later in Hong Kong than in mainland as the University of Hong Kong had to rely on a mainland university that had connections with a pharmaceutical firm.

Commenting on a global shutdown of AstraZeneca’s phase 3 Covid-19 vaccine trials after a female participant in the United Kingdom experienced a rare but serious spinal inflammatory disorder, Yuen said it was possible that the woman got the disease from another source, instead of the vaccine.

He said it was natural that some clinical trials had to be halted temporarily for safety reasons.

Pascal Soriot, chief executive of AstraZeneca, told investors in a private conference call on Wednesday that the woman’s diagnosis had not been confirmed yet but she would be discharged from hospital soon.

Soriot said the clinical trial had also been halted in July as a participant was found to have neurological symptoms. However, the case was later proven unrelated to the vaccine treatment.

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