Wednesday, 1 April 2020

UK scientists enrol volunteers for coronavirus vaccine trial

Oxford team to recruit up to 510 healthy adults without Covid-19 in race to stop further spread

Oxford scientists are enrolling the first volunteers to test a UK coronavirus vaccine, in a dramatic acceleration of the typical pace of drug development.

The trial will recruit up to 510 healthy adults, aged 18 to 55, to test the vaccine called ChAdOx1 nCoV-19. The participants will not receive the vaccine for some weeks.

While screening of participants takes place, the vaccine will continue to be assessed in animal trials at the Public Health England (PHE) laboratory at Porton Down, near Salisbury and, simultaneously, be manufactured to clinical grade standard at a University of Oxford facility.

Prof Adrian Hill, the director of the Jenner Institute at the University of Oxford, said: “Vaccines are being designed from scratch and progressed at an unprecedented rate. The upcoming trial will be critical for assessing the feasibility of vaccination against Covid-19 and could lead to early deployment.”
The UK effort to produce a vaccine quickly is one of many happening around the world. Photograph: Pedro Vilela/Getty Images

The Oxford team previously worked on a rapid vaccine response during the Ebola outbreak in west Africa in 2014. Hill said coronavirus had posed an “even greater challenge”.

The team needs people without Covid-19 and is likely to exclude anyone on medication and women who are pregnant, breastfeeding or intending to become pregnant during the study. Some will be injected with the vaccine and others with a control injection for comparison. It is expected to be months before scientists know whether the vaccine is effective, as larger trials will be needed and participants’ immune response will need to be monitored.

The team started work on 10 January, the same day China reported details of the novel coronavirus to the World Health Organization. Since then, it has progressed rapidly from candidate vaccine to animal testing to human trials.

Under normal circumstances, trials in humans would not begin until animal experiments had been completed. But because similar vaccines have worked safely in trials for other diseases, and due to the overwhelming challenges posed by the pandemic, the work has been accelerated. The trial has been approved by UK regulators and ethical reviewers.

Prof Stephen Evans, of the London School of Hygiene and Tropical Medicine, said: “There are risks that some aspects of pre-human testing have been reduced or omitted, but the benefits of getting the vaccine as quickly as possible could outweigh such potential theoretical risks.”

The UK’s chief scientific adviser, Sir Patrick Vallance, suggested this month that 12-18 months was a realistic timeframe for a vaccine to be available, but the Oxford team is aiming for earlier than this.
The vaccine is an intramuscular injection that uses a harmless, non-replicating virus to carry RNA (genetic instructions) from the coronavirus into the body’s cells.

Once inside, the body’s cells absorb the instructions and start churning out copies of the “spike protein” on the surface of the virus. In theory, these proteins are released into the body and should trigger the immune system without causing any illness.

Previous studies suggest the vaccine should work with only a single dose. Vaccines that operate the same way have been used safely in thousands of people, aged from one week to 90 years, for diseases ranging from malaria and TB to Mers, another coronavirus, and Ebola. None is in any routine immunisation programme, but they have been used previously in the UK.

In parallel with the trial, production of the vaccine is being increased ready for larger trials, and, if these are successful, rapid deployment, especially for NHS workers, elderly people, and those with underlying health conditions.

The UK effort is one of several around the world, including a trial by the US company Moderna, which gave the first dose to a participant last week.

(Source: The Guardian)

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