On Wednesday, AstraZeneca and Oxford University admitted a manufacturing mistake that posed concerns over their Covid-19 vaccine after announcing that it had been "highly effective" against the virus early this week.

Pascal Soriot, chief executive of the British manufacturing firm, was had said in a Bloomberg News article on Thursday that an additional research will be conducted to test a lower dose in AstraZeneca's trials that performed much better than a full quantity.

Soriot had this to say about following the news: "Now that we've found what looks like a better efficacy we have to validate this, so we need to do an additional study."

Oxford University stated in a comment on Wednesday that most of the vials used throughout the trials did not have the necessary vaccine dosage and that several volunteers received half a dose. The company stated that it addressed the issue with the authorities and decided to finish the late-stage trial with two parties. According to the report, the manufacturing issue was resolved.

"As we communicated in Monday's press event there is strong merit in continuing to further investigate the half dose/full dose regimen," the manufacturing company reported.

The news comes as AstraZeneca, who works with Oxford University, has been met with concerns about its performance rate. Some analysts have said that it could delay its chances of an early approval by regulators in the United States and the European Union.

Neither AstraZeneca nor Oxford University's preliminary official announcements suggested a dosing mistake. However, Mene Pangalos, head of non-oncology development and research at AstraZeneca, said Monday to Reuters that the explanation for the half-dose was "serendipity" and a touch of good fortune.

Vaccine questioned by experts

"AstraZeneca/Oxford get a poor grade for transparency and rigor when it comes to the vaccine trial results they have reported," assistant professor of biostatistics at the University of Florida, Natalie Dean, tweeted this on Tuesday, also mentioning that having to announce a study based on a dosing error was "not desirable."

A further issue of uncertainty arises from the attempt to combine results from two groups of participants, who obtained different dosing amounts to achieve an average of 70 percent of efficacy, David Salisbury and an associate member of the Global Health Program at the Chatham House think tank, said to the Associated Press.

"You've taken two studies for which different doses were used and come up with a composite that doesn't represent either of the doses," Salisbury commented of the data. "I think many people are having trouble with that."

Although some researchers pointed out that the vaccine studies are an experiment and that coincidental results are common.

"This was a very fortunate error," a professor of molecular virology at the University of Leeds, Nicola Stonehouse, stated. "It's an experiment, and sometimes experiments don't go the way you think. Sometimes things are unexpected. But they realized what happened, and that's good experimental science."

By the end of the year, the first groundbreaking COVID-19 vaccinations will be available, and while this is excellent news for state health officials, surveys have also shown that the public's confidence in COVID-19 vaccines seems to be low.