What Else Can Go Wrong With AstraZeneca’s Covid-19 Vaccine?

Late last spring, when Operation Warp Speed was planning for the eventual availability of Covid-19 vaccines, it placed orders for hundreds of millions of doses including 100 million from Pfizer/BioNTech, 100 million from Moderna, 100 million from J&J, and 100 million from Novavax. But the biggest order by far was for 300 million doses for the AstraZeneca/Oxford vaccine. This disproportionate order was justified by the belief that the latter vaccine would be much cheaper than the others and that it would possibly be able to be stored in refrigerators and not the extremely low temperatures that would be required for the Pfizer/BioNTech and Moderna vaccines.

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Unfortunately, AstraZeneca was hit with troubles in its large scale phase 3 clinical trials. First, its clinical program was put on hold for seven weeks while AstraZeneca clinicians investigated the occurrence of what was described as a neurological condition, consistent with transverse myelitis, in two study participants. After closely looking into the data, keeping in mind that transverse myelitis can be caused by a variety of factors not related to the vaccine, the FDA allowed AstraZeneca to continue its program.

In late November 2020, AstraZeneca released the results of its study which proved confounding. Patients who received two full doses of the AstraZeneca/Oxford vaccine showed efficacy of 62%. However, for those patients who MISTAKENLY received a half-dose followed by a full dose, efficacy was 90%. Had this error not been made, reviewers would have come away with the impression that this vaccine was quite inferior to those of Pfizer/BioNTech and Moderna which yielded efficacies of about 95%. But, there were others concerns raised by this study. First, only about 2800 patients had gotten the low dose, high dose regimen – not enough to make a conclusive assessment. More troubling was that no one in that arm of the study was over 55 years of age. Clearly, AstraZeneca had to run another study to convince the FDA that it truly had a viable dosing protocol particularly for people over 55.

In the meantime, Pfizer/BioNTech, Moderna, and now J&J have launched their vaccines and millions have already been vaccinated in the U.S. It is hoped that AstraZeneca will have its study completed for filing with the FDA in April. While on hold in the U.S., AstraZeneca launched its vaccine in the U.K. in December where a proud nation has purchased 100 million doses of its home-grown vaccine. The AstraZeneca/Oxford vaccine is also available in Europe where, unfortunately, new safety problems have arisen. There are now reports on the continent that this vaccine is associated with severe blood clots. As a result Denmark, Norway and Iceland have suspended its use until more data can be assessed.

Given all that has gone on, It is no surprise that people are shying away from the AstraZeneca/Oxford vaccine. In Germany, a country anxious for vaccinations, people have exhibited a strong preference for the Pfizer/BioNTech vaccine. As reported by Melissa Eddy in the New York Times, two weeks after the delivery of 1.45 million doses of the AstraZeneca/Oxford vaccine in late February, only 270,986 had been administered. ­A recent survey has shown that, while 81% of Britons believe that the AstraZeneca/Oxford vaccine is safe, only 43% of Germans and 33% of the French consider it so. It’s going to be hard for AstraZeneca to turn this around in the short term.

Turning back to the U.S., what is the Biden administration going to do about the AstraZeneca/Oxford Covid-19 vaccine? The New York Times reports that there are tens of millions of doses of this vaccine sitting in American manufacturing facilities awaiting its potential approval. Chances are that, even if this were to get an Emergency Use Authorization by the F.D.A., this vaccine will be viewed as inferior by Americans. President Biden has already announced that we will have close to 600 million doses of Covid-19 vaccines available by July. With another Covid-19 vaccine, that from Novavax possibly ready by May, it is not likely that Americans will be clamoring for the AstraZeneca/Oxford vaccine, given the availability of these others.

If as the New York Times reports, there truly are countries who would like access to this vaccine, why not offer the opportunity to acquire the AstraZeneca/Oxford vaccine to the World Health Organization, which has strongly advocated for more widespread access of Covid-19 vaccines to other parts of the world? The price of this vaccine as well as its relatively easy storage requirements make it well suited for this purpose.

I was the president of Pfizer Global Research and Development in 2007 where I managed more than 13,000 scientists and professionals in the United States, Europe, and