AstraZeneca Manufacturing Error Clouds Vaccine Study Results

[PeteS in CA]

AstraZeneca Manufacturing Error Clouds Vaccine Study Results

https://www.nbcnewyork.com/news/local/astrazeneca-manufacturing-error-clouds-vaccine-study-results/2746793/

AstraZeneca and Oxford University on Wednesday acknowledged a manufacturing error that is raising questions about preliminary results of their experimental COVID-19 vaccine.

A statement describing the error came days after the company and the university described the shots as “highly effective” and made no mention of why some study participants didn't receive as much vaccine in the first of two shots as expected.

In a surprise, the group of volunteers that got a lower dose seemed to be much better protected than the volunteers who got two full doses. In the low-dose group, AstraZeneca said, the vaccine appeared to be 90% effective. In the group that got two full doses, the vaccine appeared to be 62% effective. Combined, the drugmakers said the vaccine appeared to be 70% effective. But the way in which the results were arrived at and reported by the companies has led to pointed questions from experts.
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Before they begin their research, scientists spell out all the steps they are taking, and how they will analyze the results. Any deviation from that protocol can put the results in question.

In a statement Wednesday, Oxford University said some of the vials used in the trial didn’t have the right concentration of vaccine so some volunteers got a half dose. The university said that it discussed the problem with regulators, and agreed to complete the late stage trial with two groups. The manufacturing problem has been corrected, according to the statement.

WHAT ABOUT THE RESULTS THEMSELVES?

Experts say the relatively small number of people in the low dose group makes it difficult to know if the effectiveness seen in the group is real or a statistical quirk. Some 2,741 people received a half dose of the vaccine followed by a full dose, AstraZeneca said. A total of 8,895 people received two full doses.

The deeper one thinks into this, the more confused the interpretation. IMO, either AstraZeneca's tests to date should be regarded as demonstrating 62% efficacy with the possibility of tests begun in the US possibly demonstrating better efficacy - possibly acceptable, as the normal minimum target is 50% efficacy - or approval should be put on hold until AstraZeneca has sufficient efficacy and safety data from testing in the US. Being nobody of consequence beyond being a possible recipient, I think the latter, no EUA until the quality of the data is good and consistent, would be better.

[jmyrlefuller]

It may have turned out to be a fortunate accident—but indeed, it looks like this one may not get the EUA as soon as they'd like.

[PeteS in CA]

https://medicalxpress.com/news/2020-11-additional-astrazeneca-vaccine-company.html

AstraZeneca says its vaccine needs 'additional study'

The head of British drug manufacturer AstraZeneca said on Thursday further research was needed on its COVID-19 vaccine after questions emerged over the protection it offers, but the additional testing is unlikely to affect regulatory approval in Europe.

AstraZeneca and its partner, the University of Oxford, announced on Monday that it was seeking regulatory approval for the vaccine after it showed an average 70-percent effectiveness.

That rate jumped to 90 percent when an initial half-dose then a full dose was given, similar to that in rival vaccines in development by Pfizer/BioNTech and Moderna.

But US scientists have said the higher rate of effectiveness came during tests in people aged 55 and under, and was discovered by accident during the clinical trials.

The head of the Oxford Vaccine Group, Andrew Pollard, said this week that further evidence will be available next month, but the result was still "highly significant".

The issue to me seems to be what the vaccine's actual efficacy is - 62%? 70%? 90%? - rather than whether the vaccine could be approved. Nothing is perfect in this world, but if I'm offered a choice of two products, one of 70% effectiveness and the other of more than 90% effectiveness, both at the same cost to me, I'd choose the one that is more effective.