Not sure if there have been any further publications, aside from initial Lancet article by the Oxford study group:Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK
Certainly, further analysis of the data is ongoing, since this was just the first interim analysis. And there will assuredly be more infections over time- hence, more medium/long-term trends to sort out.
As AmberG mentioned, the the 90% efficacy result came from an error in dosing. The problem is that was found in a small subset of participants trialed (just over 2700 received the half-dose primer, out of nearly 24K over the four studies), which is not properly powered to give definitive clinical efficacy results. That result is unlikely for the FDA, EU's EMA or the UK's MHRA to consider in their approval process.
Oxford/AstraZeneca will likely have to enroll at least one additional
study (with many more participants randomized into the half-dose primer group) to prove
90% efficacy protection against getting any COVID. What they can
claim now, however, is at least 62% efficacy against getting any COVID disease (statistically relevant from the full dose primer regimen)- and this alone does meet FDA/EMA's published threshold for emergency use authorization (EUA). More importantly, it appears that no one
who received the full two dose regimen developed severe COVID- perhaps that was what the AstraZeneca CEO was discussing? I'm not sure on that. I am sure that AstraZeneca/Oxford's messaging since the beginning has seemed a little too 'forward' and that a bit more circumspection may have been useful.
Then again, even 62% is generally better than any
influenza vaccine. And 100% prevention of severe disease
is the key finding. The whole business about lockdowns/social restrictions, etc., is about preventing morbidity/mortality. If enough people get a vaccine that provides near-complete protection against severe disease, then the lockdowns/restrictions would end. Because then
COVID becomes 'just like the flu'- endemic, but not hugely disruptive.
The verbal pontification from AstraZeneca needs to stop. The regulators have closely scrutinized these results for longer than they might otherwise for EUA, likely because of this public posturing (due to politics, need for instillation of public confidence in the process, and the mere fact that there was an error in the study- which always causes a regulator to train their sights, etc.).
All that being said, imho, the regulators need to emergency authorize this vaccine yesterday. And we can finally get down to the business of mass immunizations in India.