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New UK ‘challenge’ trial to fast-forward Covid-19 vaccine
The Boris Johnson government on Tuesday said that only a vaccine candidate that has proved safe in initial trials will be given to some 90 volunteers for the so-called ‘human challenge’ trial.
Healthy young volunteers aged 18 to 30 years in the UK are to be inoculated with a Covid-19 vaccine candidate and then exposed to the virus in a controlled environment to expedite the eventual development of a safe and tested vaccine for the entire population.
The Boris Johnson government on Tuesday said that only a vaccine candidate that has proved safe in initial trials (such as the one at the University of Oxford) will be given to some 90 volunteers for the so-called ‘human challenge’ trial.
Medics and scientists will closely monitor the effect on the volunteers 24 hours to see exactly how the vaccine works and to identify any side effects. The ‘human challenge’ method of trial has long been used, including in colonial India to develop the vaccine for smallpox.
The trial is due to begin in January 2021, with results expected by May, officials said, adding that such human challenge studies have been performed safely and have played important roles in accelerating the development of treatments for diseases including malaria, typhoid, cholera, norovirus and flu.
Deputy chief medical officer Prof Jonathan Van-Tam said: “A safe, fully approved, and meticulously controlled human challenge model for Covid-19 that is conducted by experienced experts may help in the search for safe and effective vaccines.”
“First, for the many vaccines still in the mid-stages of development, human challenge studies may help pick out the most promising ones to take forward into larger Phase III trials.
“Second, for vaccines which are in the late stages of development and already proven to be safe and effective through Phase III studies, human challenge studies could help us further understand if the vaccines prevent transmission as well as preventing illness,” he added.
The first stage of the project will be delivered by a partnership between Imperial College London, the Royal Free Hospital’s specialist and secure research unit in London and industry-leading clinical company hVIVO, which officials said has pioneered viral human challenge models.
The aim will be to discover the smallest amount of virus it takes to cause a person to develop Covid-19 infection. This is known as a virus characterisation study. Volunteers will be monitored for up to a year after participating in the study to ensure their long-term well-being.
Once this first phase is completed, researchers will deploy the human challenge model which officials said will provide an “unrivalled opportunity” to study closely how vaccines work in the body to stop Covid -19.
Meanwhile, Patrick Vallance, chief scientific officer, told a parliamentary committee that a vaccine against coronavirus will not eradicate the disease or be widely available before the spring, amidst some reports that it could be available after Christmas.
Before Covid-19, it took at least five years to develop a vaccine from scratch, with an average time of 10 years, but new vaccine technologies had helped to shrink that timeframe, he said.
Stressing that a number of vaccines had been shown to trigger antibodies, Vallance said there was still a long way to go before a vaccine was widely available, adding that it was unlikely it would be rolled out for use in the community before spring 2021.
According to him, Covid-19 was unlikely to be completely stamped out: “It is likely that this disease will circulate and be endemic…Clearly as management becomes better, as you get vaccination which would decrease the chance of infection and the severity of the disease … this then starts to look more like annual flu than anything else.”
