A person in PPE

Oxford / AstraZeneca’s Covid-19 vaccine can be 90 percent effective

By Adam Vaughan

A Covid-19 vaccine that doesn’t need to be stored at very low temperatures has been found to be 70 percent effective on average, with the potential rising to 90 percent depending on the dosage.

In large-scale studies involving more than 20,000 people in the UK and Brazil, 131 people were infected with the disease. That is based on preliminary results released today by vaccine developers AstraZeneca and Oxford University.

“We have a vaccine for the world. We have a highly effective vaccine that prevents serious illness and hospitalization, ”said Andrew Pollard of Oxford University at an online press conference.


The vaccine’s 70 percent effectiveness is much less than what Pfizer, BioNTech, and Moderna reported in the past few weeks, over 90 percent. However, in a subgroup of more than 3,000 people who were given half a dose followed by a full dose a month later, the number rose to 90 percent. Two full doses one month apart showed an effectiveness of 62 percent.

Sarah Gilbert, also at the University of Oxford, told the press conference that more research was needed to find out why half the dose seems to make the body respond better. “It could be that giving a small amount of the vaccine at the beginning and then giving it a large amount will produce the largest and most effective immune system response,” she said.

Pollard said the finding was fascinating as the entire team expected that two high doses would give the best immune response.

The test results show that the vaccine prevents mild and severe illness. There is some evidence that it also inhibits transmission, Pollard and Gilbert said, although full analysis on this aspect is still underway. The results are “extremely encouraging,” the Wellcome Research Foundation said in a statement.

It is crucial that the vaccine can be stored in the refrigerator and not at -70 ° C, as the vaccine from Pfizer and BioNTech requires, which simplifies the logistics in the supply chain. Half a dosage regimen also offers the prospect of far more starting doses.

AstraZeneca’s Pam Cheng said at the press event that the company will have more than 300 million doses available worldwide by the end of March next year, a number that could double given the promise of half a dose for the first doses. She added that the company can produce around 200 million cans a month. Britain has ordered 100 million doses of the vaccine.

Even if you combine AstraZeneca’s vaccine production capacity with that of Pfizer and Moderna, there aren’t enough vaccine doses for the world, so capacity needs to be increased, Pascal Soriot, managing director of AstraZeneca, told the press event. “There is no competition,” he added.

Research is still being conducted into how long the immunity of the vaccine from AstraZeneca and Oxford University will last. However, Gilbert said she was optimistic that it would have “good shelf life,” referring to related vaccines being developed for the coronavirus that causes MERS and which provided about a year of protection.

When asked about the side effects of taking the Covid-19 vaccine, she previously said that in smaller phases of development, people had reported aching arms, fever and headache. “It’s pretty short-lived,” she said. “It’s not uncommon after vaccination.”

AstraZeneca’s Mene Pangalos announced at the press conference that the company is in discussions with regulators in the UK, US and the European Union to approve the vaccine. “This vaccine and other vaccines will make the difference [to the pandemic]”Said Gilbert.

The UK Department of Health and Welfare said: “The Independent Medicines and Health Products Regulatory Agency will do its critical work to assess whether the vaccine meets strict standards of safety, efficacy and quality once it receives full data from Oxford / AstraZeneca had received. If authorized that [National Health Service] will continue to spread, starting with the most vulnerable. “

More on these topics: