HONG KONG (BLOOMBERG) - An experimental dual vaccine for both influenza and the new coronavirus delivered via a nasal spray will enter human studies in Hong Kong next month, a top infectious diseases doctor said.
The early-stage clinical trial will enroll about 100 adults, said Dr Yuen Kwok Yung, chair of infectious diseases in the University of Hong Kong's department of microbiology.
The candidate vaccine is similar to a nasal spray flu immunisation already on the market that's designed to start working where respiratory viruses typically enter the body: the nose.
"Our idea is that we want both influenza and Covid-19 protection at the same time," Dr Yuen said in an interview.
Research on the experimental spray received funding from the Coalition for Epidemic Preparedness Innovations in Norway and Hong Kong's government, and will join dozens of clinical trials around the world aimed at identifying safe and effective vaccines to prevent Covid-19.
China started initial clinical studies last month of a nasal spray vaccine for Covid-19 co-developed by researchers at Xiamen University and the University of Hong Kong, as well as by vaccine maker Beijing Wantai Biological Pharmacy Enterprise Co.
The dual flu-Covid-19 vaccine is based on a temperature-adapted, weakened and replication-deficient flu virus that only grows in the upper airway.
Its developers used genetic engineering to delete the virus's NS1 protein and insert the receptor binding domain of the spike protein of the Sars-CoV-2 virus, Dr Yuen said. "And then we showed very well that it works in animals," he said.
Besides potentially protecting against two viruses at once, the approach aims to stimulate an immune response at the site of the mucus membrane in the nose, Dr Yuen said.
Research by scientists at Imperial College London published in the journal Science on Friday indicate a strong mucosal immune response is important for helping people stave off respiratory infections.
"I do think that a mucosal vaccine is a great idea," Dr Yuen said.
A Chinese manufacturer will make the experimental vaccine for the phase one study starting next month, he said. The trial will seek to demonstrate its safety as well as the optimal dose. Results are anticipated a few months later.