On Wednesday morning, the UK authorized AstraZenecasay (NASDAQ: AZN) candidate for coronavirus vaccine for emergency supply. The first doses of COVID-19 vaccine AstraZeneca (formerly known as AZD1222) are being released today with the aim of starting vaccinations early in the new year.
The UK’s Medicines and Healthcare Products Regulatory Agency (MHRA) recommends two full doses given four to twelve weeks apart. This is the dosing regimen that occurred 62% effectively in clinical trials in the United Kingdom and Brazil.
You may remember an unintentional administration of a half-dose / full-dose regimen that was more than 90% effective in a smaller group of patients. Unfortunately, data available for the MHRA were not sufficient to persuade the agency to deviate from the two full doses received by the vast majority of participants in clinical trials.
The European Medicines Agency (EMA) and the Food and Drug Administration are not on the same page as the MHRA. Consequently, timelines for similar authorization for AstraZeneca are still unclear.
Noel Wathion, executive director of the EMA, told reporters on Tuesday that AstraZeneca had not even submitted an application. Although AstraZeneca submitted certain data, this was not sufficient to justify a conditional marketing license.
In the US, the COVID-19 vaccine AstraZeneca will be bumpy going forward. The company’s CEO alluded to more convincing clinical trial data to come, but the results we’ve seen so far do not meet the FDA’s predetermined efficacy threshold. In addition, the FDA has made it clear that it is not prepared to authorize a candidate without some important data from a US study.