In the preliminary results of its Phase 3 clinical trial, the COVID-19 vaccine from Oxford University, developed in collaboration with drugmaker AstraZeneca, has been shown to be 70.4 percent effective. In fact, that rate includes results from two separate dosing approaches, including one where two full strengths were applied, which was 62 percent efficient, and a far more promising dosage experiment using a half-dose and a full-strength dose to be followed, which was 90 percent efficient.
The findings of Oxford may not have the eye-catching high effectiveness headline totals of Pfizer and Moderna's recent announcements, but for a few different reasons, they may potentially represent some of the most promising yet. First, if that second dosage strategy is true through later results and further analysis, it implies that the Oxford vaccine can be administered in lower amounts and provide greater efficacy (if it is much less effective, there is no reason to use the full two-dose method).
Second, at normal refrigerator temperatures between 35 ° and 45 ° F, the Oxford vaccine can be stored and transported, whereas the other two vaccine candidates need storage at lower temperatures. That helps to eliminate the need for more advanced equipment at clinics and hospitals where it will be administered during transport and on-site.
A separate approach to either Moderna's or Pfizer's, which are both mRNA vaccines, is also used in the Oxford COVID-19 vaccine. When it comes to human therapeutics, this is a relatively unproven technology, which involves using messenger RNA to provide blueprints to the body of a person to build proteins that are effective at blocking a virus, without any virus present. The nominee from Oxford University is an adenovirus vaccine, which is a much more sophisticated technology that has been in use for decades and involves genetically manipulating a common cold virus on the weekend and using it to activate a person's own natural immune response.
Finally, it is also cheaper, partly because it uses proven and tested technology for which a strong and mature supply chain is already available, and partly because it is easier to ship and store.
24,000 patients were included in the Phase 3 trial for the Oxford vaccine and by the end of the year, it is projected to rise to 60,000. To date, safety data indicate no major risks, and out of the 131 reported cases in the interim review that provided these findings, none of those receiving either a vaccine dose developed a serious or hospitalization-requiring event.
This is good news for potential vaccination programs, as it incorporates a variety of supply chains into the apparently effective treatment of COVID-19 vaccines. In terms of being able to inoculate widely as quickly as possible, we're much better off having not just multiple effective vaccines, but multiple different types of effective vaccines.