Photo: John Cairns / AP
The news from the British-Swedish pharmaceutical company AstraZeneca on Monday sounded good: The vaccine against the coronavirus developed by the company together with the University of Oxford prevents with an average of 70 percent probability of contracting Covid-19.
According to the company, the interim evaluation of the phase III study showed: The AZD1222 agent offered 90 percent protection if the study participants first received half a dose and a month later a full one.
Around 2,700 test persons in Great Britain were vaccinated.
In contrast, a second group of around 8,900 test subjects were given two full doses of the vaccine.
However, this variant was only 62 percent effective.
If you add the two results together to an overall result, the result is a value of 70 percent effectiveness.
The path that the pharmaceutical company took in the study is now igniting more and more criticism.
At first it was unclear why the scientists working for the pharmaceutical company in the study acted with half a dose.
The company later admitted it was an oversight.
Side effects such as tiredness, headache or arm pain were lower in the test subjects.
Then it turned out that the dosage was only half as high as intended.
It was apparently based on a packaging error, according to a media report.
After all, a mistake that led to a positive result.
"The reason we took half the dose is a lucky coincidence," Mene Pangalos, head of non-cancer research and development at AstraZeneca, told Reuters.
He doesn't see any problems.
The error had been corrected and the study continued without changes.
This was agreed with the supervisory authority.
A second point that experts rate critically: in this group no test person was older than 55 years.
Moncef Slaoui had drawn attention to this fact.
The immunologist directs the US government's vaccine development program.
Pangalos confirmed this information on Wednesday, according to the New York Times.
People are particularly susceptible to severe Covid-19 courses the older they are.
Possibly these circumstances could reduce the chances of the drug getting an emergency approval.
But that's speculative at this point.
Further data is still missing to come to a valid statement.
On Monday only interim results of a combined phase II and phase III study were reported.
There is also criticism that AstraZeneca has combined the results of the two differently designed clinical studies to an overall effectiveness of 70 percent.
“You did two studies that used different dosages.
In the end, they come to a result that neither of the two cans represents, ”says David Salisbury of the British think tank Chatham House of the AP news agency.
"I think a lot of people have a problem with that." According to Pangalos, the company is planning a global study to better compare the two results.
Blockbuster or stock market inhibitor?
The AstraZeneca vaccine works differently than the two mRNA agents from the pharmaceutical manufacturers Pfizer / Biontech and Moderna.
It is a vector vaccine, a long-known process.
The researchers used a chimpanzee virus to trigger an immune response to the coronavirus.
The development of AZD1222 was considered extremely promising.
It can therefore be mass-produced and is very cheap.
It should cost less than one euro per dose.
And unlike Pfizer / Biontech and Moderna vaccines, it can be stored in regular refrigerators for months.
Although the AstraZeneca vaccine was traded as a blockbuster - that is the name of particularly successful drugs in the pharmaceutical industry - the latest development has not convinced investors.
The company's stock is down about five percent this week.
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