Researchers from Hong Kong and Macao have developed a vaccine for the coronavirus and hope to start clinical trials within months. They aim to reserve eight million doses for residents of the two cities once the vaccine is ready.
According to the South China Morning Post, the team has developed a vaccine that stops a key part of the infection process by preventing the coronavirus from attaching itself to human cells, and has managed to induce a strong immune response as early as seven days in mice, rabbits, and monkeys injected with the vaccine. Their findings were published in the science journal Nature last Wednesday.
“The coronavirus uses its spike protein receptor binding domain (S-RBD) to attach to receptors in human lung cells,” corresponding author Professor Zhang Kang from Macau University of Science and Technology’s (MUST) Faculty of Medicine said.
“This is the most important step in the infection process, so we knew that if we could stop that from happening, we would be able to block the virus from invading the body.”
The finding was particularly significant as samples taken from all of the animals tested, including the monkeys, which are closely related to humans, were able to prevent the binding process and neutralised infection by a lab-made SARS-CoV-2 “pseudovirus”.
Zhang said using the RBD protein to make the vaccine also reduced unwanted side effects while producing a stronger antibody than in human patients who had recovered from COVID-19.
“We still do not know if the effects would last longer than the few months we have been tracking it, or if the vaccine could work against future mutations of the coronavirus,” he added.
Separately, scientists at the University of Hong Kong have also been working on a vaccine for the coronavirus, based on a previously developed nasal spray influenza vaccine by infectious disease expert Professor Yuen Kwok-yung.
In January this year, Yuen said it would take the team months to conduct animal tests and another year for human trials.
Johnson Lau Yiu-nam, adjunct professor in the department of applied biology and chemical technology at Hong Kong Polytechnic University, who was also involved in the vaccine development study with Zhang, said their vaccine could go to the clinical trial phase “within a few months, or even weeks”.
Lau said they would need to recruit anywhere between 10,000 to 40,000 volunteers for the trial, but did not reveal which countries they would be recruiting from.