Oxford University admitted that by mistake “Differences” in how you administer doses of COVID-19 vaccine to volunteers in trials, but explained that the methods for measuring the concentration of the antidote had already been “worked out”.
In a statement, the British university intends dispel growing doubts appeared in recent days with efficacy of up to 90%, which was observed in the subgroup that received first half the dose and then the full dose of a product developed in collaboration with the Swedish-British pharmaceutical company AstraZeneca.
After announcing the preliminary results of the third round of trials on the 23rd, the university is implicitly admitting that the doses given to the trial participants were based on error.
A panel of experts led by Andrew Pollard and Sarah Gilbert initially reported that the vaccine, offered in two doses, prep and booster, was effective. effective on average by 70.4%although changing the amount of each dose will affect the result. When half the dose is administered, followed by the full dose, the effectiveness rate is 90% – and reduces transmission – and drops to 62% when volunteers receive two full doses of the antidote.
After the announcement, it became known that the differences in the number of doses administered between the different groups were due to error, and that the dose that achieved 90% effectiveness was assigned to a group with much fewer participants, which for some implies questioning the results.
In a note, the university explains that in its research “used two dose levels based on the same concentration measure was used in phase I, but as a result of differences in the manufacturing process for the last study, it was later shown that this method overestimated the dose in new batches, resulting in half the dose being administered as the first dose.
Add this “When it became clear that a lower dose was used”, the question was referred to the regulatory body A test plan for this combination was agreed to allow the research team to “include both approaches in phase III trials”. “Concentration measurement methods have been developed and we can ensure that all vaccine batches are now equivalent,” the conclusion says.
For its part, an AstraZeneca spokesman stated that The test was conducted “to the highest standards.” and more analyzes are expected to determine the duration of protection afforded by a vaccine.
According to the Financial Times, the head of the US vaccine development funding program, Moncef Sloughi, said on the 24th that a subset of just 2,300 people had received the most effective dose was limited to those under 55 years of age., with a lower risk of developing severe COVID symptoms, a fact that neither the university nor AstraZeneca disclosed when submitting their data. For this reason, Sloughie believes the difference in vaccine efficacy was “accidental.”