Physician Views: What role for AstraZeneca's COVID-19 vaccine candidate?

Over the past week, scrutiny of the first Phase III data released for AZD1222, the COVID-19 vaccine candidate being developed by AstraZeneca and the University of Oxford, has continued to increase. On Friday, AstraZeneca CEO Pascal Soriot conceded that rather than modify its ongoing US study, the company would now initiate a separate, global Phase III trial in an effort to confirm higher efficacy for AZD1222 when a lower first-dose is administered (a finding that came about by chance due to a dosing error).

In contrast, Moderna released data from its final efficacy analysis of a US Phase III trial on Monday, confirming its mRNA-based vaccine to be 94.1% effective and 100% effective at preventing severe cases of COVID-19. Further, Pfizer and BioNTech's mRNA-based vaccine has delivered similarly impressive results and on Monday was granted emergency use authorisation in the UK.

So based on what we know about AZD1222, what role could this vaccine play in slowing and ending the COVID-19 pandemic? As has been widely discussed, AZD1222 uses more traditional vaccine technology making it easier and cheaper to manufacture, distribute and use.

Many governments, though now in discussion to increase their supply of mRNA vaccines, have bet heavily on AstraZeneca and the University of Oxford's candidate. It too, according to AstraZeneca, appears effective at preventing severe disease and hospitalisation, which could prove critical factors, and European and UK approvals could be imminent,  reports suggest.

To get a better understanding of what role AZD1222 could play ahead of subsequent data readouts, we are conducting a short survey with US and European (France, Germany, Italy, Spain and UK) based infectious disease specialists, asking the following questions…    

Q. Results from a third potential COVID-19 vaccine (known as AZD1222) have been released showing 62% effectiveness at preventing COVID-19, with no hospitalisations or severe cases of disease reported in participants receiving the vaccine. This is based on data from 8895 study participants.

This is below the approximate 95% efficacy rate of two mRNA-based COVID-19 vaccines reported in recent weeks. However, as AZD1222 uses an adenovirus viral vector its co-developer AstraZeneca anticipates manufacturing capacity of up to 3 billion doses in 2021 on a rolling basis, pending regulatory approval.

Furthermore, the vaccine can be stored, transported and handled at normal refrigerated conditions (2-8 degrees Celsius/ 36-46 degrees Fahrenheit) for at least six months and administered within existing healthcare settings. It will also be provided at cost price for the duration of the pandemic.

Based on these provisional data and logistical factors do you think AZD1222 should be approved?

Yes

No

___________

Q. If approved, on the strength of these available efficacy data how confident are you that utilisation of AZD1222 will play a key role in ending the COVID-19 pandemic on a global basis?

1 – Not confident            2            3            4 – Moderately confident            5            6              7 – Very confident   

___________

Q. In a smaller cohort of participants (n=2741) aged up to 55, when AZD1222 was given initially as a half dose followed by a full dose at least one month apart, it was shown to be 90% effective at preventing COVID-19 (reportedly based on 3 events in the vaccine arm versus 30 in the comparator arm). 

Further studies are ongoing to accumulate additional data for this half-dose/full-dose regimen. In the meantime, do you think this regimen should be approved based on available results?

Yes

No

___________

Q. It has been suggested that the initial half-dose of AZD1222 may generate a more effective immune response (versus an initial full dose), hence a higher efficacy rate in this cohort. How confident are you that subsequent data will confirm a higher efficacy rate (which is relatively close to the 90% already disclosed) for this dosing regimen?

1 – Not confident            2            3            4 – Moderately confident            5            6              7 – Very confident

___________

Q. Preliminary data for the half-dose/full-dose regimen suggests that AZD1222 may reduce asymptomatic COVID-19 transmission. If confirmed, how significant a factor would this play to make you positively reassess the potential role of this vaccine?

1 – Not significant           2            3            4 – Moderately significant           5            6              7 – Very significant

___________

Results and related analysis will shortly be published for FirstWord Pharma PLUS subscribers to read, with the opportunity for non-FirstWord Pharma PLUS subscribers to purchase these findings. To be notified when poll results and analysis become available, please click here

To read more Physician Views articles, click here.