The analysis done of the vaccine candidate, which AstraZeneca develops together with the University of Oxford, is based on data from two Phase III studies currently underway in the UK and Brazil involving over 23 participants across a range of ages and demographics. Studies are also underway in several other countries, including the US, Japan and Russia, and are expected to enroll a total of approximately 000 people.
Effective vaccine
Particular attention has been paid to AstraZeneca's vaccine candidate AZN1222 as it has been indicated as one of the more cost-effective projects currently in development. AstraZeneca has said that it will sell the vaccine at manufacturing cost, which has been estimated to be between 3 and 4 USD per dose. This can be compared to the more expensive mRNA-based vaccines that Pfizer / BioNTech and Modern developed. Pfizer has indicated a price of USD 20 per dose while Moderna has announced that a dose of their candidate will be in the price range of USD 32-37.
Can be stored in a regular refrigerator
Another issue that has been widely discussed is the temperature required for vaccine storage. AstraZeneca's vaccine can be stored in a standard refrigerator, at temperatures between 2 and 8 degrees Celsius, for up to six months, which makes distribution and handling easier. The same temperatures also apply to Moderna's vaccine, but only for storage for up to a month, as longer storage requires -4 degrees. In this comparison, Pfizer is grappling with the fact that their vaccine must be stored at -70 degrees Celsius.
Mistakes led to better results
Both Moderna's and Pfizer's vaccines showed an effectiveness of around 95 percent in initial analyses of ongoing studies. The US Food and Drug Administration (FDA) had previously said it was willing to approve vaccines that showed 50 percent effectiveness.
Regarding the study on AstraZeneca's candidate AZN1222, the path to a result has not been entirely straight, which was clearly reflected in Monday's announcement.
When the researchers at Oxford University distributed the vaccine in late April, they noticed that side effects of the vaccine, such as fatigue and aches in the head and arm, were much milder than expected in most participants. It was then discovered that around 3 participants had received half a dose instead of a full one. Instead of stopping the study, the participants who had received half the first dose were allowed to continue and received their planned second full dose a month later.
The results of the different dosing surprised the researchers. The incorrect dosing was found to lead to an efficacy of 90 percent, which is comparable to the levels achieved by Pfizer and Moderna with their vaccines. Meanwhile, the normal dosing with AZN1222, where participants received two full doses one month apart, showed only a 62 percent efficacy. Overall for the study, the average efficacy was 70 percent.
The researchers say they cannot provide a complete explanation for why the results turned out the way they did, but Sarah Gilbert, who is a professor at Oxford University and who led the research, to This may have to do with the incorrect dosage triggering the immune system differently.
Criticism from investment banks
The American investment bank SVB Leerink, which specializes in the pharmaceutical sector, was quick to accuse AstraZeneca of whitewashing the results. AstraZeneca's shares, which traded slightly lower after the results announcement, were further pressured when comments from SVB Leerink began to circulate. The shares lost a total of 2 percent during Monday trading.
Further investigation is needed
Moncef Slaoui, who is the chief scientific advisor within Operation Warp Speed, says in an interview with Bloomberg News that it is important to understand how the differences in the study arose and that more analysis is needed to see how AZN1222 compares to the two competing vaccines from Pfizer and Moderna, something he hopes to gain better insight into in two to three weeks. According to Bloomberg News, AstraZeneca's communications director Michele Meixell announce that full data will be presented in a medical journal “in due course”.
AstraZeneca will apply for emergency authorisation from drug authorities around the world to begin distributing the vaccine. The company will also approach the World Health Organisation for this. WHO to help quickly get the vaccine to the world's developing countries. At the same time, the company is preparing manufacturing, with an annual capacity of up to 2021 billion doses of vaccine targeted for 3.