Oxford University's COVID-19 vaccine, developed in partnership with drug maker AstraZeneca, has been shown to be 70.4% effective in preliminary results of its phase 3 clinical study. This rate actually includes data from two different dosing approaches, including one using two full strengths which was 62% effective, and a more promising dosing attempt using a half dose and a full dose which was 90% effective .
The Oxford results may not have the eye-catching high-impact headlines of Pfizer's recent announcements and Moderna, but they might actually represent some of the most promising for a variety of reasons. First, if this second dosing strategy applies to later results and further analysis, it means the Oxford vaccine can be given in smaller amounts and offers greater efficacy (there is no reason to use the full two-dose method, though it is so much less effective).
Second, the Oxford vaccine can be stored and transported at standard refrigerator temperatures between 35 ° and 45 ° F, while the other two vaccine candidates must be stored at lower temperatures. This helps avoid the need for more specialized equipment during transportation and on-site in clinics and hospitals where they are administered.
Oxford's COVID-19 vaccine also uses a different approach than Moderna's or Pfizer's, both of which are mRNA vaccines. This is a relatively unproven technology when it comes to human therapeutics, which uses messenger RNA to provide blueprints to a person's body to build proteins that effectively block a virus in the absence of a virus. Oxford University's candidate is an adenovirus vaccine, a much more established technology that has been in use for decades. A cold virus is genetically modified at the weekend, thus triggering a person's natural immune response.
After all, it's cheaper too – partly because it uses proven technology that already has a robust and mature supply chain in place, and partly because it is easier to transport and store.
The Phase 3 study for the Oxford vaccine enrolled 24,000 participants and is expected to grow to 60,000 by the end of the year. Safety data to date show no significant risks, and among the 131 confirmed cases in the interim analysis that produced these results, none of those who received a vaccine dose developed a severe case or one that required hospitalization.
This is good news for potential vaccination programs as it introduces a variety of supply chains into what appears to be an effective vaccine treatment for COVID-19. We're much better off not only having multiple effective vaccines, but also having multiple different types of effective vaccines in order to get a broad vaccination as quickly as possible.