Oxford University and AstraZeneca release their COVID-19 vaccine results

By Emily Henderson, B.Sc.Nov 23 2020

AstraZeneca, a global biopharmaceutical company, has just released their results from its interim analysis of AZD1222, a vaccine being trialed to prevent COVID-19 alongside its partner, the University of Oxford.

Image Credit: AstraZeneca

The results showed that the vaccine was highly effective in preventing COVID19 and no severe cases of COVID-19 were reported in the patients that received the vaccine. There was also no hospitalizations. 131 COVID-19 cases were observed in this interim analysis.

Vaccine Efficacy

The trial looked at the efficacy of the vaccine following two different dosing regimens; the first showed vaccine efficacy of 90% when AZD1222 when given as a half-dose followed by a full dose at least one month apart. The second showed vaccine efficacy of 62% when AZD1222 was given as two full doses at least one month apart. The combined analysis of this data provided an overall vaccine efficacy of 70%.

As this is the first results published from this trial, more data will continue to be collected and additional analysis will be carried out to further refine its efficacy reading and to further understand the length of protection from COVID-19.

However, the analysis did meet its primary endpoint as it demonstrated protection from COVID-19 occurring 14 days or more after receiving both doses of the vaccine. There were also no serious safety concerns related to the vaccine and AZD1222 was said to be well-tolerated across both of the dosing regimens.

The trial itself is composed of 23,000 participants aged 18 years or over that are from diverse racial and geographic groups. The participants are healthy or have stable underlying medical conditions. Oxford University and AstraZeneca expect to enroll up to 60,000 participants as the trial continues.

Today marks an important milestone in our fight against the pandemic. 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. Furthermore, the vaccine’s simple supply chain and our no-profit pledge and commitment to Page 2 of 3 broad, equitable and timely access mean it will be affordable and globally available, supplying hundreds of millions of doses on approval.”

Pascal Soriot, Chief Executive Officer, AstraZeneca

About AZD1222

The AZD1222 vaccine was invented by the University of Oxford working alongside AstraZeneca. The vaccine is composed of a chimpanzee viral vector that is based on a weaker version of the adenovirus (common cold virus) that causes infections in chimpanzees and also contains the genetic material of the spike protein from SARS-CoV-2.

After vaccine administration, the surface spike protein is produced, which helps to prime the immune system to attack SARS-CoV-2 if it later infects the body.

AstraZeneca is already making rapid progress within their manufacturing department with a capacity of up to 3 billion doses of AZD1222 available in 2021 pending its approval.

The vaccine itself can be transported, stored, and administered at normal refrigerated temperatures (2-8 degrees Celsius) for a minimum of six months. The vaccine can also be administered within existing healthcare settings such as hospitals and doctors.

Next Steps

AstraZeneca is now working on preparing its data for submission to health authorities around the world that have a framework already in place for conditional or early approval of vaccines.

They are also working alongside the World Health Organization to receive an Emergency Use Listing to help provide access to the vaccine in low-income countries at no profit for the duration of the COVID-19 pandemic.

Alongside this, they are also submitting their interim results for publication in a peer-reviewed journal.