The Oxford/AstraZeneca vaccine may well be effective – as the developers claimed earlier this week – but enough questions have been asked about the trials and the reporting for drug regulators around the world to think long, and hard, and perhaps wait for more trial data – after all, trials are also on in the US and India – before approving the two-shot vaccine that offers protection from Covid-19.
In September, amidst rising concerns that vaccine developers would rush through trials, ignoring safety concerns as well as detailed and nuanced analysis of efficacy, companies including AstraZeneca (it is developing its vaccine in collaboration with the University of Oxford and Vaccitech Ltd, the company that has licensed the adenovirus vector platform used in the vaccine from the university’s Jenner Institute), Moderna, and the Pfizer/BioNTech combine, released elaborate protocols for their Phase 3 trials – unprecedented in the annals of vaccine development.
The coronavirus disease has resulted in huge public interest in a process that is usually restricted to the research departments of pharma companies, laboratories and research institutions, and peer-reviewed academic journals with readership in the thousands (or tens of thousands). Indeed, the results of clinical trials are usually announced in such journals, not in press releases and briefings with analysts at investment banks. But with cases exceeding 60 million, deaths nearing 1.5 million (and actual deaths being much higher), and lives and livelihoods disturbed by a virus that is airborne, it isn’t surprising that everyone is more interested in the results of vaccine trials than they are in, say, a royal wedding. Both Moderna and Pfizer/BioNTech followed this approach while disclosing the results of the trials of their vaccines, both based on a hitherto untested mRNA (or messenger RNA platform). The results were good, 90% in one case, later updated to 95% based on more readings, and 95% in another. That’s very high for a vaccine. Even better, a close reading of the results by analysts, scientists, and experts – including many amateurs with the ability to convert complex scientific papers and research into language laypeople can understand, and built huge followings on social media in the process – didn’t turn up any gaps or unpleasant surprises. Both vaccines work.
There was more riding on the AstraZeneca/Oxford vaccine, though. It only required refrigeration, compared to the Moderna and Pfizer/BioNTech ones that needed sub-zero temperatures, and it was going to be inexpensive (which meant it would end up being the vaccine of choice for low-income and poor countries). It was also going to be the first vaccine available in India – thanks to a deal between Serum Institute of India, the world’s largest vaccine manufacturer, and AstraZeneca/Oxford. There may also have been some pressure on company executives to announce the results of the trials following the success of the Moderna and the Pfizer/BioNTech vaccines.
Whatever the reason, AstraZeneca/Oxford seem to have hurried the announcement of the results – and it shows. Following the initial announcement of the results on Monday, it has emerged that what was reported as a trial involving an alternative approach to dosing was actually a mistake that was converted into an experiment; that the results announced combine those from two separate trials with two different protocols and demographic groups; and that the data used was from sub-groups within these groups. These are worrying lapses – and have rightly been called out by scientists, epidemiologists, and bio-statisticians. They are dodgy from the perspective of science, data, and clinical trial protocols.
This is a pity – especially because the findings were also encouraging in terms of the vaccine candidate’s ability to prevent transmission (protecting infected people from developing Covid-19, and preventing transmission are two very different things) – something that is especially critical in the case of a disease that has been found to be transmitted significantly by infected people that are asymptomatic.
More trial data may substantiate the efficacy of the vaccine (some experts believe that there is a high likelihood of this), but the episode once again highlights that unlike in the case of food and fashion, there is no such thing as fast science.
PS: Late on Thursday, Bloomberg reported AstraZeneca’s CEO Pascal Soriot as saying that it may conduct an additional global trial to assess the efficacy of the vaccine after some studies raised questions over its level of protection.
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