Human trials success raises hopes for vaccine
OXFORD: Hopes for a successful COVID-19 vaccine have been boosted as results from early human trials show several vaccine candidates are inducing a strong immune response.
The results of the University of Oxford’s phase 1 human trials of its viral vector vaccine are imminent. Subjects in the trial of 1000 people are understood to have shown encouraging levels of neutralising antibodies, thought to be important in protecting against viral infection, and there were no serious side-effects.
The results also indicated that another aspect of the immune system, known as T-cells, was mobilised.
It comes as US biotech Moderna announced this week that 45 people who had been given its candidate vaccine had displayed a “robust” immune response. An efficacy trial with 30,000 Americans is due to begin on July 27.
There are now 21 vaccines globally that have begun human trials. The University of Oxford’s candidate is now in phase 3 trials, together with an inactivated vaccine candidate developed by Chinese company Sinovac. More than 150 vaccine candidates are being developed around the world.
The director of the National Centre for Immunisation Research and Surveillance, Kristine Macartney, said the early results of human trials had boosted her confidence that a successful vaccine would be produced.
“The progress that has been made and the speed at which vaccines are coming down the pipeline is nothing short of remarkable,” Professor Macartney said.
“We’ve now seen at least three publications with data from phase 1 vaccine studies for three different vaccines, and we’re anticipating the results of a major study on the Oxford candidate vaccine. “The fact that we are seeing these study results augurs extremely well for having vaccines go forward to the next development phase which is critical, taking some of these vaccines forward into studies in tens of thousands of people. What we’ve seen here is work that would normally take six years compressed into a six-month time period.”
The University of Queensland announced this week that it had begun the first dosing in phase 1 human trials of its candidate, which uses molecular clamp platform technology to stabilise the protein used to generate an immune response. UQ has partnered with CSL, which has pledged to produce millions of doses of the vaccine to help move its development into late-stage testing, and provide enough doses for widespread supply.
Adelaide scientist Nikolai Petrovsky’s company, Vaxine, has also developed a protein-based vaccine candidate, with human trials testing safety and efficacy.
While the UQ and Vaxine candidates are traditional protein-based vaccines, new technology is being used around the world that could become the next frontier in vaccine development.
“I like to say we’ve been in training for this pandemic,” Professor Macartney said. “We’ve seen a scientific revolution in the last two decades and this has resulted in really smart vaccine design approaches.
“We now have one licensed viral vector vaccine against Ebola — it’s the first vaccine of that type licensed for use in humans.”
Pharmaceutical giant AstraZeneca has agreed to supply 100 million doses of the Oxford vaccine to Britain with delivery in September or October and manufacturing plans are well under way. It also plans to supply the US with 300 million doses by about the same time. It has so far secured global manufacturing capacity for two billion doses.
A further 10,000 trial subjects have been recruited by the Oxford team in Britain, along with about 5000 in Brazil and 2000 in South Africa. A trial in the US will involve as many as 30,000 more.
