Oxford says Covid-19 vaccine highly effective, easier to distribute

AstraZeneca's late-stage trials show its Covid-19 vaccine with Oxford University is up to 90 percent effective in preventing disease.

The company on Monday said results are based on interim analysis of trials  in trials that involved 23,000 people in the UK and Brazil.

There were no hospitalisations or severe cases of Covid-19 in those who were inoculated, according to AstraZeneca.

AstraZeneca is the third major drug company to report late-stage results for a potential vaccine as the world anxiously waits for scientific breakthroughs that will bring an end to a pandemic that has wrought economic devastation and resulted in nearly 1.4 million confirmed deaths.

Dosing regimens

The trial looks at two different dosing regimens. 

A half dose of the vaccine followed by a full dose at least one month apart was 90 percent effective in the participants. 

A second regimen using two full doses one month apart was 62 percent effective.

The combined results showed an average efficacy rate of 70 percent.

“These findings show that we have an effective vaccine that will save many lives,” Professor Andrew Pollard, chief investigator for the trial, said in a statement. “Excitingly, we’ve found that one of our dosing regimens may be around 90 percent effective.’’

The researchers are not sure if the virus will mutate in a way that would make it necessary to repeat vaccination every year, but that for now that looks unlikely.

"We don't know yet if this virus will be mutating away from the immune response," Pollard said, adding: "There is no evidence of that yet."

Asked whether the vaccine would be likely to give longer-term protection, Pollard said:

"We've got optimism about immune response lasting at least a year," but that trials needed more time to be able to give any confirmation of durability

READ MORE: Latest Covid-19 updates for November 23

Cold temperatures

Pfizer and Moderna last week reported preliminary results from late-stage trials showing their vaccines were almost 95 percent effective.

Yet unlike many of its rivals, the AstraZeneca-Oxford vaccine does not have to be stored at ultra-cold temperatures, making it far easier to distribute in developing countries.

AstraZeneca CEO Pascal Soriot said the simple supply chain for AstraZeneca’s vaccine and the company’s commitment to provide it on a non-profit basis during the pandemic mean it will be affordable and available to people around the world.

“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,’’ Soriot said.

“Because the vaccine can be stored at fridge temperatures, it can be distributed around the world using the normal immunisation distribution system. And so our goal … to make sure that we have a vaccine that was accessible everywhere, I think we’ve actually managed to do that,” Pollard said.

READ MORE: Moderna and Pfizer's success gives world more hope

Virus surge puts US, UK on back foot

The results come as Covid-19 infection rates are rising in most US states and in many countries amid a resurgence of the virus that is once again prompting governments to shut down businesses and restrict social gatherings around the world. 

England is still in the middle of a four-week lockdown that has closed all non-essential shops, while in the US, the government's top health agency has recommended that Americans not travel to visit family and friends over the Thanksgiving holiday this week.

READ MORE: US hospitals and staff under immense pressure with Covid-19 surge

200 million doses available this year

AstraZeneca will have enough of its vaccine for 200 million doses by the end of 2020, with drug substance for 700 million doses by the end of the first quarter of 2021 globally, operations executive Pam Cheng said.

Cheng told a briefing that the company would keep the "active" drug substance in stock while it awaited regulatory approval around the world.

She said there would be enough vaccine for 20 million doses in Britain by the end of the year, with enough "active" drug substance for 70 million doses for the UK by the end of Q1 2021.

She said she expected that to translate into 4 million finished vaccine doses by the end of 2020, and 40 million finished doses by the end of Q1 next year.

Those calculations were based on using two full doses, she said, although trial data suggests higher efficacy when the initial shot is a half dose.

"If we go with a half dose you can imagine for the initial dose, we will be able to double the number of vaccinations here," she said.

She said the figures referred to the vaccine doses being manufactured by AstraZeneca, and not those being made by manufacturing partners.

Britain's bet on Oxford vaccine

Regulators must approve the vaccine before it can be widely distributed.

Britain has ordered 100 million doses of the Oxford vaccine.

British Health Secretary Matt Hancock said he felt “a great sense of relief” at the news of the vaccine’s effectiveness.

He said just months ago, as the virus raged, “the idea that by November we would have three vaccines, all of which have got high effectiveness … I would have given my eye teeth for.”

READ MORE: J&J starts two-dose trial of its Covid-19 vaccine candidate