LONDON -- U.K.-based pharmaceutical giant AstraZeneca and England's University of Oxford announced Monday that late-stage trials show their COVID-19 vaccine was up to 90% effective in preventing the disease.
The results are based on interim analysis of phase 3 trials in the United Kingdom and Brazil, which looked at two different dosing regimens. One regimen showed vaccine efficacy of 90% when the drug, called AZD1222, was given as a half dose, followed by a full dose at least one month apart. A second regimen showed 62% efficacy when given as two full doses at least one month apart. The combined analysis from both dosing regimens showed an average efficacy of 70%, according to press releases from AstraZeneca and Oxford.
There were a total of 131 COVID-19 cases in the analysis, and no hospitalizations or severe cases of the disease were reported in participants receiving the vaccine candidate, according to the press releases.
"These findings show that we have an effective vaccine that will save many lives," Andrew Pollard, director of the Oxford Vaccine Group and chief investigator of the Oxford vaccine trial, said in a statement Monday. "Excitingly, we’ve found that one of our dosing regimens may be around 90% effective and if this dosing regime is used, more people could be vaccinated with planned vaccine supply."
AstraZeneca, which has promised not to profit from the vaccine "for the duration of the pandemic," said it will now immediately prepare to submit the data to regulators around the world -- including in the United Kingdom, Europe and Brazil -- that have framework in place for conditional or early approval. The company will also seek an emergency use listing from the World Health Organization for an accelerated pathway to vaccine availability in low-income nations.
Meanwhile, Oxford said it is submitting the full analysis of the interim results for independent scientific peer review and publication.
"Today marks an important milestone in our fight against the pandemic," AstraZeneca CEO Pascal Soriot said in a statement Monday. "This vaccine’s efficacy and safety confirm that it will be highly effective against COVID-19 and will have an immediate impact on this public health emergency."
Clinical trials of AZD1222 are also being conducted in the United States, Japan, Russia, South Africa, Kenya and Latin America, with planned studies in other European and Asian countries. In total, AstraZeneca said it expects to enroll up to 60,000 participants globally.
The company said it is "making rapid progress in manufacturing" and expects to produce up to 3 billion doses of AZD1222 in 2021 on a rolling basis, pending regulatory approval. The vaccine can be stored, transported and handled at normal refrigerated conditions for at least six months and administered within existing health care settings.
"The vaccine’s simple supply chain and our no-profit pledge and commitment to broad, equitable and timely access means it will be affordable and globally available, supplying hundreds of millions of doses on approval," Soriot said.
The U.K. government has already placed orders for 100 million doses of the AstraZeneca/Oxford vaccine candidate, along with 40 million doses of another developed by Pfizer and BioNTech, which has shown in a phase 3 trial to have 95% efficacy with no serious safety concerns to date.
Pfizer and BioNTech announced Friday that they had submitted a request to the U.S. Food and Drug Administration for emergency use authorization of their COVID-19 vaccine candidate.
"It definitely made me feel more optimistic and more hopeful in the future with everything that’s going on," said Sebastian Tosarr-Cattino.
Tosarr-Cattino said participation in AstraZeneca's trial was a way to help join the fight against COVID-19.
"I’ve been pretty affected by COVID-19. I know friends and family that have gotten sick and I know people have lost their friends and family too and I’m a relatively young 24 year old who doesn’t have any previous history of very severe illnesses and I just thought man I want to be able to get back to normal and if this is something to go ahead and do it I might as well join the fight against it," the Madison, WI native said.