The Covid vaccine Petra Moinar prepares syringes with the AstraZeneca vaccine before it is administered on March 8, 2021 at the Battersea Arts Center in London, England.

Chris J Ratcliffe | Getty Images News | Getty Images

AstraZeneca’s Covid shot, dubbed the “Vaccine for the World”, has had high hopes since its inception. However, unlike other coronavirus vaccines, the shot developed by AstraZeneca and Oxford University has been plagued from problem to problem.

AstraZeneca’s problems began almost as soon as preliminary trial data was released and have continued ever since.

The drug maker “seems to be having a real PR problem in the US and Europe,” Sunaina Sinha Haldea, managing partner of Cebile Capital, told CNBC on Thursday, warning that its “PR problem is raising confidence in the vaccine outdoors could undermine “the UK”

Here is a timeline of all the issues that AstraZeneca has encountered over the past year:

November 2020 – process data dispute

AstraZeneca released an interim clinical trial analysis showing that its Covid vaccine has an average of 70% effectiveness in protecting against the virus. The result was initially welcomed by the global community, which was already supported by positive results for the recordings by Moderna and Pfizer-BioNTech.

However, upon further examination it became clear that the value of 70% came from the combination of the analyzes of two separate dosage regimens within the experiments. One dosing regimen showed 90% effectiveness when subjects received half a dose followed by a full dose at least a month apart. The other showed 62% effectiveness when given two full doses at least one month apart.

AstraZeneca admitted that the half-dose regimen was a mistake, but described it as a “useful mistake” and a “coincidence”. However, it has been criticized by US experts, and AstraZeneca’s chance announcement of the bug was arguably the start of its reputational problems.

January 2021 – delivery dispute

In early January, the UK began rolling out the AstraZeneca-Oxford University vaccine. It had an added bonus for the country: the majority of its cans would be made in the UK.

It wasn’t long, however, before a dispute over supplies with the European Union began after reports that the drug maker was failing to make its contracted supplies to the bloc.

A very public dispute over contracts erupted, sparking a history of bitter relations between the EU and the UK and the Anglo-Swedish drug maker. The EU has made waves suggesting AstraZeneca is rerouting supplies from the UK to the block

January 2021 – Effectiveness in disputes over 65 years of age

90 year old Margaret Keenan is greeted by staff as she returns to her ward after becoming the first patient in the UK to receive the Pfizer / BioNtech COVID-19 vaccine at the University Hospital Coventry, UK December 8, 2020.

Jacob King | Reuters

March 2021 – Dispute over blood clots

Late March 2021 – US data dispute

AstraZeneca worries continued this week – even though they started at a high level for the drug maker. On Monday, the results of a large U.S. study showed the vaccine was safe and highly effective, raising hopes that it could soon seek U.S. approval for the shot.

However, on Tuesday, a US health agency announced that AstraZeneca may have included “out of date” information in its study results, which may cast doubts on published rates of effectiveness.

AstraZeneca responded that the numbers released Monday were “based on a pre-determined interim analysis with a February 17th data deadline,” saying it would share its primary analysis within 48 hours of the most recent efficacy data.

On Wednesday, the company released updated Phase 3 trial data for its Covid-19 vaccine, showing that its vaccine is 76% effective – slightly lower than the 79% rate published on Monday.

What’s next for AstraZeneca?

The problems facing AstraZeneca could continue as EU leaders virtually meet on Thursday to discuss possible vaccine export bans that could hit the drug maker. However, the EU and the UK said on Wednesday that they wanted to find a “win-win” solution to the ongoing supply problem.

The continued negative coverage of AstraZeneca has led some viewers (and certainly the UK media) to point out that post-Brexit vaccine has become a target for negative sentiment in Europe directed against the UK. It has also been suggested that the shot could be the victim of vaccine nationalism in the US, where competing shots came from Moderna and Pfizer-BioNTech (although BioNTech is a German company).

Regardless of the underlying causes, AstraZeneca’s reputation has been badly damaged.

As Shore Capital health analysts wrote Thursday, “Any confusion about results can quickly turn into concerns about the safety and effectiveness of vaccines, even if those concerns are not based on solid evidence.”

The AstraZeneca vaccine was “particularly badly affected by confusion about the data reported. Importantly, this confusion can lead to an erosion of trust in vaccines, which are proven, life-saving drugs.”