Controversy over new AstraZeneca trial data raises more unwanted vaccine questions

Despite extensive evidence and repeated regulatory assurances that the Oxford-AstraZeneca vaccine is safe to use, confidence in the life-saving jab remains worryingly low.

From questions over its efficacy among the elderly, to reports of blood clots in some recipients, the vaccine’s rollout has been repeatedly slowed and hampered outside Britain.

On Monday, encouraging trial data from the US raised hopes that any lingering doubt surrounding the jab could finally be put to bed. Hours later, however, new concerns were raised by American health officials that AstraZeneca had included “outdated information" in its large-scale study, which may have provided "an incomplete view of the efficacy data”.

Dr Anthony Fauci, the White House’s chief medical adviser, said the company’s interpretation of the trial results seemed to be “in my mind ... an unforced error”.

“I was sort of stunned,” he said on Tuesday morning, by how positive the results were, even compared with previous trial data from the company. “We felt that we could not remain silent.”

The setback, at a time when millions of people around the world are waiting to be vaccinated, threatens to further undermine faith in the jab.

Already, research suggests that large chunks of Europe have lost complete faith in the vaccine, once heralded as a tool that could bring an end to the pandemic on account of its simple logistical requirements – foremost, that it can be kept at fridge temperature for months – and low costs.

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A recent YouGov poll of 8,000 people across the continent found that 55 per cent of Germans now consider the jab to be unsafe – a 15-point increase in a month – while 32 per cent consider the vaccine to be safe. In France, 61 per cent of the people surveyed considered it to be unsafe. Both Italy and Spain saw a 27-point rise in the number of people who no longer trust the vaccine.

Yet when it comes to the mRNA vaccines developed by BioNTech and Moderna, no spikes in anxiety have been recorded. A small consolation, perhaps, but with the majority of doses of these two vaccines already secured by the west, that leaves the rest of the world even more reliant on the much-maligned AstraZeneca option.

It’s against this backdrop that the US National Institutes of Health (NIH) released a rare statement in which it questioned the findings of the latest clinical study of the jab.

Dr Fauci said it was “likely” that the vaccine is still “very good”, but explained that the NIH’s data and safety monitoring board (DSMB) was “concerned" that the information included in AstraZeneca's press release was “somewhat outdated and might in fact be misleading a bit”.

He later told the Financial Times: “When they saw the release, they were quite upset. We felt it was essential that we, the NIH, needed to have some sort of response, otherwise it would look like we were covering something up.

“It is really a shame. Because the vaccine is likely a very good vaccine. And this does nothing but confuse the situation.”

Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said it was “not unknown” for the interpretation of trial results to be challenged. However, he said, “it is usually done in private, so this is unprecedented in my opinion”.

The latest AstraZeneca trial, which has been conducted in sites across America, Chile and Peru, is ongoing, with Monday’s results based on interim analysis of data that has a cut-off point of 17 February – a detail not initially revealed by the company.

This means that any important developments seen in the trial after that date, which could impact conclusions drawn around the vaccine’s efficacy and safety, have yet to be taken into consideration.

But although AstraZeneca failed to provide this initial timeline in its press release, it made clear its findings were not final or definitive. The pharmaceutical giant said it would “continue to analyse the data and prepare for the primary analysis to be submitted” to the US drugs regulator in “the coming weeks”.

Realistically, the picture in America will have changed substantially from 17 February, given the rising prevalence of the highly transmissible Kent variant. Last month, the US Centres for Disease Control and Prevention (CDC) predicted that it would become the predominant variant by March, fuelling a possible resurgence in cases.

Prof Evans speculated that one explanation for the NIH’s statement “might well be” that the AstraZeneca trial is being conducted “when there is a large amount of a new variant about more recently”. Even so, studies in the UK and elsewhere have shown that the vaccine remains effective in neutralising the Kent variant, raising the question of what exactly the issue is.

Nonetheless, Prof Evans said he was not concerned by this latest development – “unless they had found a safety issue that was being hidden, which does not appear to be the case”.

Dr Stephen Griffin, a virus expert at the University of Leeds, said the whole saga has highlighted “the importance of data being provided at the same time as summaries being made public”.

While AstraZeneca has announced that it will release more data on its vaccine trials “within 48 hours”, the US Food and Drug Administration said it intends to independently review “every bit of data themselves” – rather than relying solely on the company or any other interpretation.

The rest of the world will watch on in the meantime, waiting for answers from yet another perplexing episode that is likely to fuel anxieties over the vaccine.

There is no doubt that AstraZeneca’s PR campaign has been far from flawless throughout the pandemic. It failed initially to reveal the details of a dosage mistake that, in a moment of “serendipity,” as one company chief put it, improved the efficacy levels of the jab. After that, the firm’s unusual strategy of pooling data from clinical trials in its UK-based analyses sparked widespread confusion.

It should come as no surprise, then, that a country which has viewed the vaccine with suspicion for months should now continue to walk such a cautious line. Realistically, it is only with the benefit of hindsight that we will be able to conclude whether this approach was justified, and who was to blame in this latest misstep.