Oxford ‘challenge trials’ will expose volunteers to coronavirus in lab

The rewards of finding a Covid cure are enormous, but speeding up the whole process comes with costs

Bill Gardner

OXFORD scientists leading the search for a Covid-19 vaccine are planning to expose volunteers to the virus as part of a controversial “challenge trial”.

They are hoping to attract healthy recruits before the end of the year in order to test whether the jab protects them from the disease – for which there is yet no cure.

Prof Adrian Hill, director of the Jenner Institute and co-leader of the Oxford vaccine project, said only younger participants would be exposed to the virus because they were unlikely to fall seriously ill.

In challenge trials, volunteers are deliberately exposed to a disease in a controlled laboratory environment.

Researchers are keen to begin the trials because the virus is fading so rapidly in the community, making it difficult to prove a vaccine is effective.

The World Health Organisation says that human challenge trials are ethical when they meet certain criteria.

Prof Hill said his team were already making preparations for a challenge trial within months. “We’re hoping to be doing challenge trials by the end of the year,” he told the Guardian website. “This might be in parallel or after the phase-three trial is completed. They’re not competing options, they’re complementary.”

Sir John Bell, Regius Chair of Medicine at Oxford University, who is also working on the vaccine, said new drugs including remdesivir would help ensure the safety of challenge trial volunteers. “I think some of the new neutralising therapies look pretty good, so if somebody got sick, you could fix it,” he told The Telegraph. “I suspect the challenge study will be in mid-autumn. That would be my bet.”

It came as more than 100 prominent scientists, including Prof Hill and 15 Nobel Laureates, signed an open letter to Dr Francis Collins, the head of the National Institutes of Health in the US. “If challenge trials can safely and effectively speed the vaccine development process, there is a formidable presumption in favour of their use, which would require a very compelling ethical justification to overcome,” the letter published by 1 Day Sooner, an organisation that advocates for challenge trials, said.

‘Some of the new neutralising therapies look pretty good, so if somebody got sick, you could fix it’

Never have the rewards been so high but, make no mistake, the risks being run in the race to produce a vaccine against Covid-19 are huge. Virtually every day, newspapers blaze headlines detailing the latest breakthroughs and setbacks. Every big nation has its favourite vaccine, all diplomatically described as “leading candidates” by the World Health Organisation. In Britain, we cheer for the boffins at Oxford and Imperial. In the US, Moderna sits at the vanguard of President Trump’s “operation warp speed”. In China, Cansino Biologics is the jab with a “good safety profile” already being administered to the nation’s heroic troops.

The race is as impressive as it is essential. As Bill Gates put it: “Humankind has never had a more urgent task than creating broad immunity for coronavirus… we need to develop a safe, effective vaccine... and we need all of this to happen as quickly as possible.” And that is happening. Science that would normally take years has been completed in months and tens of billions are being invested in vaccine manufacturing plants, many of which will never produce a thing. “It’s a small price to pay for getting ahead on production,” says Mr Gates, who is funding several of them.

We are, however, rolling the dice; playing a high stakes game at a casino where the cards will not necessarily fall in our favour. It’s the price – the gamble – humanity must pay now for not investing adequately in pandemic preparedness over the past 20 years.

The risks fall into at least three broad categories: scientific, commercial and ethical.

Scientists are for the most part clear-eyed. They know through bitter experience that vaccines which seem promising in early trials often fail to perform in the real world. HIV, malaria, dengue – the list of failed vaccines is frighteningly long. For the moment, Sars-cov-2 appears oddly slow at mutating. This provides scientists with a relatively static target to aim at, but that could change. After all, the virus is under little pressure to mutate. It has 7.8 billion of us without immunity to run through. That will change as immunity builds, naturally or through vaccination.

On the commercial side, things are starting to get a bit iffy, to my eye at least. Too many of those headlines are sparked by press releases issued by big pharma ahead of the data. When the hard science comes along a few days later, there are invariably gaps, side effects and other nasties the spin doctors failed to mention. Were we in normal times, the regulators would be having a field day. Expect more of this as bulk orders are bagged and vaccines move into production.

On the ethics front, with the pressures of time and money building, we should remain vigilant.

Yesterday, more than 100 prominent scientists, including 15 Nobel laureates, signed an open letter calling for volunteers to be deliberately exposed to coronavirus after receiving a vaccine to see if it offers protection. Such “challenge trials” could greatly accelerate vaccine development – and the “1 Day Sooner” initiative has more than 30,000 would-be volunteers in 140 countries who say they are willing to be used as the guinea pigs. The Oxford vaccine team – one of many battling to find candidates who face a high chance of natural exposure to the virus – said such studies could be “feasible and informative”.

This is by no means a cut and dried ethical question but it is not normal. Challenge studies are generally only conducted when there is a proven treatment for the pathogen you are to be infected with. The other side of the coin is a needs-must argument. Tens of thousands are dying every day, yet the risks to the young and fit are fleetingly low. If they are happy to take the risk, why not take them up on it? The sooner we get a proven jab, the quicker we can protect the most vulnerable.

These and many thousands of other discrete risks can be sensibly dealt with. The bigger problem comes when they start to overlap, creating the danger that we compromise too often and quietly slip towards disaster. And what disaster looks like with a vaccine is not measured in direct but indirect deaths – the refusal of millions to be inoculated because of fear. And therein lies the biggest risk of all. Just one small mistake is all it takes for this unprecedented global exercise in commercial and scientific brinkmanship to go horribly wrong.