AstraZeneca Pausing Vaccine Trial Over Participant Illness a Good Thing, Experts Say

Experts have welcomed a decision by pharmaceutical firm AstraZeneca and the University of Oxford to pause a coronavirus vaccine study after a participant fell ill, saying it proves safety protocols are being correctly followed.

The study was halted following a "standard" review process, so safety data could be investigated, a spokesperson for the COVID-19 Vaccine Team at the Oxford Vaccine Centre told Newsweek in a statement.

"This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the studies, while it is investigated, ensuring we maintain the integrity of the trials," the spokesperson said.

In large trials involving many participants, illnesses can happen by chance "but must be independently reviewed," according to the spokesperson.

The vaccine being developed by AstraZeneca and the University of Oxford is known as ChAdOx1, after the chimpanzee adenovirus which it uses to deliver coronavirus genes into cells.

British health secretary Matt Hancock told U.K. broadcaster Sky News the pause was "obviously a challenge" but comes after a study was stopped and restarted earlier in the summer.

He called it a standard process within clinical trials and said it would "not necessarily" set back the development, depending on what is found.

Hancock said the move underlines that "we will absolutely do everything necessary to ensure a vaccine is safe as well as effective."

Experts not involved in the study said the decision was the correct one to ensure the vaccine is safe.

Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, U.K., said in a statement that coincidental events can happen in trials, and investigations are required to see if they are a result of the vaccine.

Such events are to be expected as people over 70 have been included in the trials, he said.

"The whole way of conducting vaccine trials with independent data and safety monitoring boards, as well as regulatory processes, is intended to protect the participants in the trials and is why trials are conducted," Evans said.

"This very incident shows that the Oxford trial, and any other trials conducted in the U.K., are monitored very carefully and precautions are taken to protect both the trial participants and those who might get the vaccine in the future."

Evans said it was too soon to speculate whether the vaccine was the cause of the illness.

Even if it is, it would not necessarily mean the vaccine could not be used as other factors may be involved. It may be the case that the vaccine is safe to use in some people and not others, he said.

Ian Jones, professor of virology at the U.K.'s University of Reading, said in a statement: "I think unfortunate more than sinister would be the best description of the halt."

Doug Brown, chief executive of the British Society for Immunology, said this type of pause is not uncommon, "and in fact, it's exactly what we should all want to see the vaccine researchers doing to ensure the safety of any potential vaccine above everything else."

Brown said: "Vaccines can prevent illness and save lives, but it is also vital that they are thoroughly tested before being rolled out on a wide scale to ensure they are safe to use.

"Because safety is so critical, vaccine trials are incredibly complex, and each vaccine goes through many stages of testing both in the lab and in clinical trials.

"All vaccine clinical trials have numerous strict safety procedures in place to monitor the health of participants."

The pause "is one of these safety procedures kicking in," he said.

Brown said the news shows why it is "critical" to conduct thorough and robust trials, and one more reason why researchers must not be pressured to rush through a vaccine for widespread use.

Dr. James Gill, honorary clinical lecturer at Warwick Medical School, said in a statement the decision "should be paradoxically considered a good thing."

The action "should be championed as good science and great transparency for the public who are waiting for news on a COVID-19 vaccine," Gill said.

"Personally, I would be suspicious of a vaccine for a novel virus which was developed without any hiccoughs or pauses.

"Science on T.V. is great, and usually gets completed in the course of an episode. In a real lab, chemistry, patients, and biology don't often follow a nice simple course, which is why from the start scientists have said that this COVID vaccine development will take considerable time to get right and safe."

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A stock image shows a person preparing to administer a vaccine. A coronavirus vaccine trial has been paused after a participant fell ill. Getty