LONDON:
Britain’s AstraZeneca said on Monday its vaccine for the novel coronavirus could be around 90% effective without any serious side effects.
The vaccine developed by Oxford University was 90% effective in preventing COVID-19 when it was administered as a half dose followed by a full dose at least one month apart, according to data from the late-stage trials in Britain and Brazil.
No serious safety events related to the vaccine have been confirmed and it was well tolerated across both dosing regimens, it said.
Efficacy fell to 62% when the vaccine was given as two full doses at least one month apart. The combined analysis from both dosing regimens resulted in an average efficacy of 70%. All results were statistically significant.
The Astra vaccine does not require ultra-cold storage which may make it easier to administer than the Pfizer-BioNTech shot, which needs to be refrigerated at -70 degrees.
“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,” Pascal Soriot, Astra’s chief executive, said in a statement.
The overall effectiveness was lower when measured across different dosing regimes, giving an apparent initial advantage to rival vaccines from Pfizer and Moderna.
The results ranged between 62% and 90% efficacy depending on the vaccine dosage.
The 70% average is lower compared with the efficacy of coronavirus vaccines trialed by rivals Pfizer/BioNTech and Moderna which have come in above 90%.
But scientists also noted there may be advantages to AstraZeneca’s vaccine.
“Importantly, from what we have heard the vaccine seems to prevent infection not just disease. This is important as the vaccine could reduce the spread of the virus as well as protect the vulnerable from severe disease,” said Peter Horby, a professor of emerging infectious diseases and global health at the University of Oxford.
He also noted that the Oxford vaccine “can be stored in the fridge, as opposed to the freezer like the other two vaccines, which means it is a more practical solution for use worldwide.”
Poriot said that the lower first dose of its experimental COVID-19 vaccine meant more people can be vaccinated more quickly, as the British drugmaker unveiled interim late-stage trial results.
“Being able to vaccinate more people faster is a really a big plus,” he told a briefing.
The British drugmaker’s preliminary trial results mark a fresh breakthrough in the fight against a pandemic that has killed nearly 1.4 million people and roiled the global economy.
British Prime minister Boris Johnson said it was “incredibly exciting news the Oxford vaccine has proved so effective in trials”.
The vaccine developed by Oxford University was most effective when it was administered as a half dose followed by a full dose at least one month apart, rather than as two full doses at least one month apart.
While the efficacy reading from Astra’s viral vector vaccine is lower than its U.S. rivals, the data will boost confidence about the chances of successfully developing a variety of vaccines using different approaches. Public health experts say the world will need many vaccines to meet global demand.
On Nov. 16, U.S.-based Moderna Inc said its experimental vaccine proved to be 94.5% effective based on an early data analysis.
A week earlier, Pfizer Inc and Germany’s BioNTech SE said their vaccine candidate had demonstrated greater than 90% efficacy that rose to 95% with analysis of full trial data.
Russia’s Sputnik-V vaccine on Nov. 11 was also shown to be more than 90% effective, though only based on 20 infections.
AstraZeneca will have 200 million doses of its candidate vaccine developed by the University of Oxford by the end of 2020, with 700 million doses ready globally by the end of the first quarter of 2021, operations executive Pam Cheng said on Monday.
Cheng told a briefing that there would be 20 million doses in Britain by the end of the year, with 70 million doses for the UK by the end of Q1 2021.
Monday’s statement said “positive high-level results from an interim analysis of clinical trials of AZD1222 in the UK and Brazil showed the vaccine was highly effective in preventing Covid-19 … and no hospitalisations or severe cases of the disease were reported in participants.”
It added: “One dosing regimen (n=2,741) showed vaccine efficacy of 90 percent when AZD1222 was given as a half dose, followed by a full dose at least one month apart.”
The pair said that regimen n=8,895 showed 62% efficacy when given as two full doses at least one month apart.
“The combined analysis from both dosing regimens (n=11,636) resulted in an average efficacy of 70 percent.”
AstraZeneca said it would “immediately prepare regulatory submission of the data to authorities around the world that have a framework in place for conditional or early approval.”
It will also seek an emergency use listing from the World Health Organization to speed up availability in low-income countries. In parallel, the full analysis of the interim results is being submitted for publication in a peer-reviewed journal.
AstraZeneca said it is looking at a capacity of up to three billion doses of the vaccine in 2021 pending regulatory approval.
It said the vaccine can be stored, transported and handled “at normal refrigerated conditions” of between two and eight degrees Celsius (36-46 degrees Fahrenheit) for at least six months.
More than 23,000 adults are currently being assessed in the trials, with the number expected to rise to up to 60,000, the statement said.
“Clinical trials are also being conducted in the US, Japan, Russia, South Africa, Kenya and Latin America with planned trials in other European and Asian countries,” it added.
Oxford professor Andrew Pollard said the latest findings show “an effective vaccine that will save many lives”.
“Excitingly, we’ve found that one of our dosing regimens may be around 90 percent effective and if this dosing regime is used, more people could be vaccinated with planned vaccine supply.
“Today’s announcement is only possible thanks to the many volunteers in our trial, and the hard working and talented team of researchers based around the world,” added Pollard, who is chief investigator of the Oxford Vaccine Trial.
The AstraZeneca vaccine uses a modified version of a chimpanzee common cold virus to deliver instructions to cells to fight the target virus, which is different than the new technology known as messenger RNA (mRNA) deployed by Pfizer/BioNTech and Moderna.