Chinese Covid-19 Vaccine Candidate Becomes First Nasal Spray to Start Clinical Trial

A Chinese-developed Covid-19 vaccine candidate has become the first nasal spray for the disease to begin human testing, as the country continues to add contenders to the global race to defeat the coronavirus.

The University of Hong Kong (HKU) announced last week that clinical trials for the spray had been approved by China’s National Medical Products Administration. The vaccine has been co-developed by HKU, Fujian province’s Xiamen University as well as vaccine-maker Beijing Wantai Biological Pharmacy Enterprise Co. Ltd.

One part of the phase 1 clinical trials kicked off on Sept. 1 in East China’s Jiangsu province, and Hong Kong trials are expected to begin in November, local media reported.

The vaccine has become the 10th candidate from China and the 32th in the world, to proceed into the human testing phase, according to the WHO’s list of candidate vaccines. It is the only nasal spray on the WHO list that has of Wednesday moved on to clinical trials.

Scientists hope that a vaccine delivered via the nose would be particularly effective in preventing infection by the coronavirus, which spreads through the respiratory tract.

Chen Honglin, a microbiologist at HKU, told Caixin on Friday that the vaccine candidate contains a weakened flu virus that carries some of the novel coronavirus’s genes.

Chen said the nasal spray could be delivered along with an injected vaccine to mount a multipronged attack on the coronavirus. Cases around the world of recovered coronavirus patients testing positive for the virus again suggest that natural immunity may last for only a few months. This also raises questions for how long vaccines would be effective, and highlights the potential need for multiple vaccinations.

The HKU nasal vaccine could also generate protection for influenza, according to Chen. Earlier this month, South Korea reported Covid-19 cases that seemed to also involve seasonal influenza, raising concerns about a double whammy of flu season and a Covid-19 resurgence this winter.

If a new wave of the coronavirus outbreak arrives together with influenza, the nasal spray will be “the easiest, most economical and practical long-term pathway,” Chen said.

As the vaccine uses a part of the coronavirus that rarely mutates, it should also be able to protect against many strains of the rapid mutating virus, Chen said.

Another advantage of the nasal spray vaccine is that it can be easily self-administered and is relatively safer for people with weakened immunity because the virus contained within it has been greatly weakened, Chen said.

Contact editor Joshua Dummer (joshuadummer@caixin.com)

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