Data, doubts and disputes: A timeline of AstraZeneca's Covid vaccine problems

Heralded as “the vaccine for the world,” AstraZeneca’s Covid shot has been accompanied by high hopes ever since its inception. But, unlike other coronavirus vaccines, the shot developed by AstraZeneca and the University of Oxford has been plagued by problem after problem.

AstraZeneca’s troubles started almost as soon as it published interim trial data, and have continued ever since.

The drugmaker “seems to have a real PR problem on its hands in the U.S. and in Europe,” Sunaina Sinha Haldea, managing partner of Cebile Capital, told CNBC on Thursday, warning that its “public relations problem risks undermining confidence in the vaccine outside of the U.K.”

Here’s a timeline of all the problems that have struck AstraZeneca in the past year:

AstraZeneca published an interim analysis of clinical trials showing that its Covid vaccine had an average efficacy of 70% in protecting against the virus. The result was initially cheered by the global community, already buoyed by positive results for both Moderna’s and Pfizer-BioNTech’s shots.

However, after further scrutiny it became clear that the 70% figure came from combining the analyses of two separate dosing regimens within the trials. One dosing regimen showed an effectiveness of 90% when trial participants received a half dose, followed by a full dose at least one month apart. The other showed 62% efficacy when two full doses were given at least one month apart.

AstraZeneca admitted the half-dose regime was an error, but described it as “useful mistake” and “serendipity.” It attracted criticism from U.S. experts, however, and AstraZeneca’s haphazard communication surrounding the mistake arguably marked the start of its reputational issues.

In early January, the U.K. started to roll out the AstraZeneca-Oxford University vaccine. It had an added bonus for the country: the majority of its doses would be made in Britain.

However, it wasn’t long before an argument over supplies started brewing with the European Union, following reports that the drugmaker was not going to fulfil its contracted deliveries to the bloc.

A very public dispute over contracts ensued, starting a saga of acrimonious relations between the EU and both the U.K. and the Anglo-Swedish drugmaker. The EU made waves suggesting that AstraZeneca divert supplies to the bloc from the U.K.

At the same time as the dispute over supplies was brewing, some European nations started to cast doubt over the AstraZeneca vaccine’s efficacy in the over-65s — arguably those most in need of the shot due to age-related Covid risks.

Germany’s vaccine committee recommended that the AstraZeneca vaccine should only be offered to people aged between 18-64, saying there was not enough trial data to assess the efficacy in people aged over 65. Several German newspapers reported that the vaccine had an efficacy rate of less than 10% in the over-65s — described as “completely incorrect” by AstraZeneca — and France’s President Emmanuel Macron poured oil on the fire, saying the vaccine seemed “quasi-ineffective” for the over-65s.

Later trial data involving older participants showed that the vaccine was safe and effective for the over-65s, and saved lives, but by then the reputational damage was done — particularly in France where vaccine hesitancy is already rife.  

At the end of January, the EU’s drugs regulator approved the use of the AstraZeneca vaccine for all adults. France, Germany and other countries then revised their earlier stances, approving the vaccine for the over-65s (with some caveats in France).

The problems for AstraZeneca got even worse in March, despite real-world data from the U.K. showing that the shot, alongside Pfizer’s, was having indubitably positive effects with coronavirus cases, hospitalizations and deaths all falling. Meanwhile, the EU’s infection rate was rising as the bloc’s vaccine rollout remained sluggish.

Then there were reports of blood clots in some people who had been vaccinated with the AstraZeneca shot, and more than a dozen European countries suspended its use pending a safety review. AstraZeneca defended its shot, saying that the number of blood clots recorded post-vaccination were lower than could be expected to occur naturally.

The World Health Organization and European Medicines Agency conducted safety reviews into the vaccine and concluded it was safe and effective and that its benefits outweighed the risks. By then, however, further damage to the AstraZeneca shot’s reputation had been done.

The woes for AstraZeneca have continued this week — despite it starting on a high note for the drugmaker. On Monday, the findings of a large U.S. trial showed that its vaccine was safe and highly effective, spurring hopes that it could soon seek U.S. clearance for the shot.

However, on Tuesday, a U.S. health agency said AstraZeneca may have included “outdated” information in the trial results, potentially casting doubt over published efficacy rates.

AstraZeneca responded that the figures published Monday “were based on a pre-specified interim analysis with a data cut-off of 17 February” and said it would share its primary analysis with the most up to date efficacy data within 48 hours.

On Wednesday, it issued updated phase three trial data for its Covid-19 vaccine that showed its vaccine to be 76% effective — slightly lower than the 79% rate published on Monday.

The issues facing AstraZeneca could be set to continue, as EU leaders meet virtually on Thursday to discuss possible vaccine export bans which could hit the drugmaker. The EU and U.K. said on Wednesday, however, that they wanted to find a “win-win” solution to the ongoing supply issue.

The ongoing negative coverage of AstraZeneca has led some onlookers (and certainly, the British media) to suggest that the vaccine has become a target for negative sentiment in Europe directed at the U.K. after Brexit. It has also been suggested that the shot could be the victim of vaccine nationalism in the U.S., where rival shots from Moderna and Pfizer-BioNTech originate (although BioNTech is a German company).

Whatever the underlying causes, AstraZeneca’s reputation has been sorely damaged.

As healthcare analysts at Shore Capital wrote on Thursday: “Any confusion about results can be quickly amplified into concerns about the safety and efficacy of vaccines even when those concerns are not based on solid evidence.”

The AstraZeneca vaccine, they noted, “has been particularly hard hit by confusion around the data reported. Importantly, such confusion can lead to an erosion of trust in vaccines which are proven, life-saving medicines.”