News of vaccines with 90 percent efficacy was welcomed the world over as cases of the coronavirus saw a renewed upsurge in recent weeks.
But there are some doubts being raised about a vaccine developed by AstraZeneca and the University of Oxford, where the company has admitted administering a wrong dosage to some participants.
This raises the question of the true strength of its efficacy claims. Scientists and industry experts are not impressed with AstraZeneca’s mistakes. The way the company earlier disclosed the results also raised some questions.
AstraZeneca Vaccine Gaffe!
AstraZeneca had reported that the 90 percent effectiveness of the vaccine was discovered accidentally when some participants were given the first shot of medicine at half the strength due to some mistake. Out of the 23,000 participants about 2,800 received the half strength dosage, and it was discovered to be 90 per cent effective in combating the disease. The next shot of the vaccine was given after almost a month later.
Nearly 8,900 participants received two full doses. Depending on the strength of the dosage—two full shots gave 62 percent efficacy and the half shot 90 percent—the average efficacy of the dosage was 70 percent.
Why did the half strength give such good results was never satisfactorily explained.
Officials in the United States have noted that the results were not clear. The head of the federal vaccine initiative. Moncef Slaoui, first disclosed that the vaccine’s most promising results did not reflect data from older people.
“There are a number of variables that we need to understand,” Slaoui said. It is still possible the difference in efficacy was “random”, he added.
This will surely delay the emergency use approval of the vaccine. “I think that they have really damaged confidence in their whole development program,” said Geoffrey Porges, an analyst for the investment bank SVB Leerink.
Michele Meixell, a spokeswoman for AstraZeneca, said the trials “were conducted to the highest standards.”
Menelas Pangalos, the AstraZeneca executive in charge of the company’s research and development, said that the error in the dosage was made by a contractor, and that, once it was discovered, regulators were immediately notified and signed off on the plan to continue testing the vaccine in different doses.
Questioned on the company’s decision to share information with Wall Street analysts and some other officials and experts but not with the public, he responded, “I think the best way of reflecting the results is in a peer-reviewed scientific journal, not in a newspaper.”
There were other issues involved too. The company said that the early analysis was based on 131 symptomatic Covid-19 cases that had turned up in study participants. But no clear data was given about how many cases showed up in each group of participants.
“The press release raised more questions than it answered,” said John Moore, a professor of microbiology and immunology at Weill Cornell Medical College.
Data of two different trials from Brazil and Britain was pooled together, which is not the accepted practice for vaccine clinical trials.
“I just can’t figure out where all the information is coming from and how it’s combining together,” said Natalie Dean, a biostatistician and an expert in vaccine trial design at the University of Florida. She added that AstraZeneca and Oxford had not done too well in terms of transparency and rigor in trial reporting.
AstraZeneca went into firefighting mode after questions were raised about its data regarding the trial efficacy. It held several calls with analysts where it disclosed more data results.
The company’s initial announcement didn’t mention the accidental nature of the discovery.
“The reality is, it could end up being quite a useful mistake,” Mr. Pangalos said in an interview with The New York Times on Wednesday. “It wasn’t putting anyone in danger. It was a dosing error. Everyone was moving very fast. We corrected the mistake and continued on with the study, with no changes to the study, and agreed with the regulator to include those patients in the analysis of the study as well.”
AstraZenaca had previously halted its trials as one patient was reported to have had an adverse reaction. But the same was not revealed publicly but was shared with analysts on a call.
The Food and Drug Administration on its part has said that it is happy with any vaccine that reports 50 percent efficacy. Though it has still withheld any comments about AstraZenanca.
AstraZeneca’s shares have fallen about 5 percent this week. Investors do not seem to be too happy with the company’s reporting of data. Its two rivals—Moderna and Pfizer—have announced vaccines that appear to be about 95 percent effective. They have used the “messanger rNA” mode for the trials. Both are certain to win emergency authorization from the F.D.A. in the coming weeks.
The AstraZenaca vaccine used a chimpanzee virus to provoke an immune response to the coronavirus. It held the most promise for an eagerly awaiting world as it was cheaper and easier to mass produce, unlike its two rivals, which are more expensive and need special storage.
Both the UK and US were eagerly awaiting the AstraZenaca vaccine, both countries having invested heavily in its success both monetarily and in administrative support.
