The measured statement from the pharmaceutical group sought to dispel any suggestion that the race to develop a vaccine – the candidate it is developing in partnership with the University of Oxford is seen as a trailblazer – had encountered significant problems.
Pascal Soriot, Managing Director of AstraZeneca, made this decision proof of his company’s commitment to “science, security and the interests of society”. The hiatus showed the company would follow these principles, he said, as a suspected serious adverse reaction experienced by a participant in a UK trial was assessed by a panel of independent experts.
But the incident was a reminder that the pharmaceutical industry is trying to achieve an unprecedented feat: wanting to beat, by several years, the previous fastest development of a vaccine. For the moment, this record is held by the mumps vaccine, which took four years to market.
Despite the anticipation of a vaccine that will arrive and free people from containment, history shows there is no guarantee. Overall, infectious disease vaccines have a success rate of around 33.4% after the start of human trials, although that rate rises to 85% for those reaching phase 3 trials.
An extraordinary scientific effort has been devoted to finding a vaccine that will prevent Covid-19 or at least alleviate the symptoms. The Oxford-AstraZeneca candidate is one of five clinical trials that use the weakened form of a common type of virus called adenovirus. The modified adenovirus provides instructions to human cells to make proteins on Sars-Cov-2, the coronavirus that causes the disease. This causes the immune system to recognize it and attack it.
Another type of vaccine uses RNA, a molecule containing genetic instructions to make viral proteins that are inserted directly into human cells. American biotechnology Moderna and the partnership between Pfizer and BioNTech are adopting this approach for their vaccines and, along with the Oxford / AstraZeneca candidate, are considered among the most advanced.
The break in the AstraZeneca trial comes as politicians have encouraged the narrative that a vaccine will arrive at “warp speed,” to quote the name of US President Donald Trump’s vaccine project.
Earlier this week, Britain’s Health Secretary Matt Hancock hoped the one in Oxford might even get regulatory approval before the end of the year, although he suggested that the start of 2021 was more likely.
Some experts said the announcement of the break would provide a useful reality check, stressing that safety was paramount.
Referring to this in a Senate hearing on Wednesday, Francis Collins, the head of the US National Institutes of Health, said: “When we say we’re going to focus on safety and not make any compromises, here is Exhibit A. “
If the trial participant’s illness turns out to be “a real consequence of this vaccine and can be shown to be cause and effect, then any doses that are currently being manufactured for it will be thrown away.” We don’t want to manufacture something that is not safe, ”he said.
Dan Mahony, co-director of healthcare at fund manager Polar Capital, said the bar for administering a vaccine may be higher than for other pharmaceuticals, as they are almost always given to people. who are doing well otherwise.
The difficulty for vaccine makers is that even clinical trials involving 30,000 people – like AstraZeneca’s current Phase 3 trial – may not trigger rare, but potentially devastating reactions.
When a swine flu vaccine was widely distributed in 1976 at the behest of then-US President Gerald Ford, a small number of cases of a serious neurological disorder called Guillain-Barré syndrome (GBS) were discovered. The increased risk was about one additional case per 100,000 people who received the vaccine, but the program had to be stopped.
Mr Mahony said regulators were always wary of one in 10,000 or 100,000 reactions that studies such as AstraZeneca would not necessarily repeat. He added: “These are great studies, but it is still difficult to identify these rare events. But one in 100,000 [adverse events] is still quite important if you plan to vaccinate up to a billion people. “
This possibility was at the root of AstraZeneca’s decision to voluntarily stay the trial, he said. “The concern in the mind of a regulator and a pharmaceutical company for any clinical trial is that of the rare events that we would not have detected statistically?”
Scientists emphasized that breaks are an integral part of drug development and don’t necessarily imply longer-term question marks about a drug’s efficacy and safety.
Jeremy Farrar, director of the Wellcome Trust, a London-based research organization, said: “It is very unusual to go through a vaccine trial and not have to put it on hold.
The condition that led to the suspension of the trial is transverse myelitis, an inflammation of the spinal cord that has a known, but very rare, association with vaccination.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, cautioned against hypothesizing a link between the participant’s disease and the vaccine.
“When a large number of people are included in the trials, coincident events can occur and when they are unexpected, an investigation is necessary to see if they are only a coincidence or a result of the vaccine”, a- he declared.
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Analysts and investors alike reacted calmly to the news that the trial was suspended. Peter Welford of Jefferies said temporary breaks were “standard clinical trial practice”. He and his team envisioned “a short-term market correction that may turn out to be inappropriate,” he added.
Describing the moderate market reaction to the news – shares edged up to almost £ 84 – as ‘reasonable’, Polar Capital’s Mr Mahony argued that the vaccine’s fate was unrelated to prospects for success anymore. broad of society. AstraZeneca has pledged not to profit from the drug during the pandemic.
He said: “I don’t think this vaccine has ever been a financial engine for them. It is more of a factor to be a good corporate citizen.
Rather, AstraZeneca’s status as one of the world’s fastest growing pharmaceutical companies stems from its oncology business, said Mahony.
“It’s a booming business and they’ve stepped in to do something about Covid from a position of strength.”
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