Pharmaceutical company AstraZeneca said Monday that late-stage trials showed its coronavirus vaccine was up to 90 per cent effective, giving public health officials hope they may soon have access to a vaccine that is cheaper and easier to distribute than some of its rivals.
The results are based on interim analysis of trials in the UK and Brazil of a vaccine developed by Oxford University and manufactured by AstraZeneca. No hospitalisations or severe cases of COVID-19 were reported in those receiving the vaccine.
AstraZeneca is the third major drug company to report late-stage results for a potential COVID-19 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.
Pfizer and Moderna last week reported preliminary results from late-stage trials showing their vaccines were almost 95 per cent effective. But, unlike its rivals, the AstraZeneca vaccine doesn’t have to be stored at ultra-cold temperatures, making it easier to distribute, especially in developing countries.
The Oxford-AstraZeneca vaccine is also cheaper. AstraZeneca, which has pledged it won’t make a profit on the vaccine during the pandemic, has reached agreements with governments and international health organizations that put its cost at about US$2.50 a dose. Pfizer’s vaccine costs about US$20 a dose, while Moderna’s is US$15 to US$25, based on agreements the companies have struck to supply their vaccines to the US government.
All three vaccines must be approved by regulators before they can be widely distributed.
Oxford researchers and AstraZeneca stressed that they aren’t competing with other projects, and that multiple vaccines will be needed to reach enough of the world’s population and end the pandemic.
“We’re not thinking about vaccinations working in terms of one person at a time. We have to think about vaccinating communities, populations, reducing transmission within those populations, so that we really get on top of this pandemic,″ said Sarah Gilbert, a leader of the Oxford research team. “And that’s what it now looks like we’re going to have the ability to contribute to in a really big way.″
AstraZeneca said it will immediately apply for early approval of the vaccine where possible, and it will seek an emergency use listing from the World Health Organization, so it can make the vaccine available in low-income countries.
The AstraZeneca trial looked at two different dosing regimens. A half-dose of the vaccine followed by a full dose at least one month later was 90 per cent effective. Another approach, giving patients two full doses one month apart, was 62 per cent effective. The combined results showed an average efficacy rate of 70 per cent.
The vaccine uses a weakened version of a common cold virus that is combined with genetic material for the characteristic spike protein of the virus that causes COVID-19. After vaccination, the spike protein primes the immune system to attack the virus if it later infects the body.
The vaccine can be transported under “normal refrigerated conditions” of 2 to 8 degrees Celsius (36 to 46 degrees Fahrenheit), AstraZeneca said. By comparison, Pfizer plans to distribute its vaccine using specially designed “thermal shippers” that use dry ice to maintain temperatures of minus-70 degrees Celsius (minus-94 degrees Fahrenheit).
Britain has ordered 100 million doses of the Oxford vaccine, and the government says several million doses can be produced before the end of the year if it is approved by regulators.