AstraZeneca and Oxford University confirmed a manufacturing defect on Wednesday that raises questions about preliminary results of their experimental COVID-19 vaccine

A statement describing the bug came days after the company and university described the recordings as “highly effective” and failed to mention why some study participants had not received as much vaccine in the first of two recordings as expected

Surprisingly, the group of volunteers who received a lower dose appeared to be much better protected than the volunteers who received two full doses.In the low-dose group, according to AstraZeneca, the vaccine appeared to be 90 percent effective In group that received two full doses, vaccine appeared to be 62 percent effective Taken together, drug manufacturers said the vaccine was 70 percent effective, but the way the results were gathered and reported by companies has got to specific questions led by experts

The partial results announced on Monday come from large ongoing studies in the USAK and Brazil to determine the optimal dose of the vaccine, as well as to study safety and efficacy. Several combinations and doses were tried with the volunteers. They were compared with others who were given a meningitis vaccine or saline solution

Before starting their research, the scientists explain all of the steps they will take and how they will analyze the results. Any deviation from this protocol could call the results into question

In a statement Wednesday, Oxford University said that some of the vials used in the study did not have the correct concentration of vaccine, so some volunteers received half a dose, The university said it had discussed the problem with regulators and agreed to complete the late stage with two groups The manufacturing problem has been fixed according to the statement

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Experts say the relatively small number of people in the low dose group makes it difficult to know whether the efficacy observed in the group is real or a statistical quirk around 2741 people received half a dose of the vaccine followed by a full dose, AstraZeneca said in total 8895 people received two full doses

Another factor: none of the people in the low dose group were over 55 years old. Younger people tend to develop a stronger immune response than older people Hence, it could be that the youth of the low-dose group is what makes them look more effective, not the size of the dose

Another point of confusion arises from the decision to merge the results of two groups of participants who received different dosage levels to achieve an average effectiveness of 70 percent, said David Salisbury and Associate Fellow of the Global Health Program at Chatham House tanks

“You did two studies that used different doses and came up with a composite that didn’t represent either of the doses,” he said of the illustration, “I think a lot of people have problems with this.”

Sarah Gilbert, one of the Oxford scientists who led the research, said the answer likely relates to providing just the right amount of vaccine to elicit the best immune response

“I think it’s the Goldilocks amount you want, not too little and not too much. Too much could also give you a poor quality answer,” she said. “So you want just the right amount and it’s a hit and so.” Miss if you’re trying to go fast to get the perfect first time ”

Details of the test results will be published in medical journals and made available to UK Regulators so they can decide whether to approve the vaccine distribution.These reports include a detailed breakdown with demographic and other information about who got sick in each group, as well as a more complete picture of the vaccine’s effectiveness

Moncef Slaoui, who runs the US Coronavirus vaccination program Operation Warp Speed ​​said in a call with reporters Tuesday that US. Officials are trying to determine what immune response the vaccine provoked and may decide to modify the AstraZeneca study in the US contain half a dose


World News – CA – Mistakes in AstraZeneca COVID-19 vaccine manufacture raise questions