The United Kingdom authorized its second Covid-19 vaccine for distribution on Wednesday. Developed by the University of Oxford and AstraZeneca, the newly approved vaccine costs less and is easier to store than the Pfizer / BioNTech vaccine, which received similar approval in the UK on December 2.
Officials said the benefits of the Oxford / AstraZeneca vaccine could speed up the vaccination effort, as the UK faces a new, more communicable variant of SARS-CoV-2, the virus that causes Covid-19.
“This approval means that more people can be protected against this virus and will help save lives,” said June Raine, chief executive of the UK health regulator, the Medicines and Health Products Regulatory Agency, in a statement.
The UK plans to vaccinate 1 million people a week and is moving to a more aggressive vaccination schedule, according to the New York Times. The country will administer the first dose of the vaccine “to as many people as possible”, instead of trying to keep supplies in reserve to ensure that everyone receives a second dose, as other countries, including the United States, have done so far.
The high stability and low cost of the Oxford / AstraZeneca vaccine can also be a boon for less affluent nations. If its effectiveness is high – and the vaccine is distributed quickly – it can save countless lives. However, some persistent questions about the results of clinical trials of this vaccine are preventing its approval in the United States, which is conducting its own tests on the vaccine’s effectiveness.
Why the Oxford / AstraZeneca Covid-19 vaccine is different from those developed by Pfizer / BioNTech and Moderna
In the UK, the Oxford / AstraZeneca vaccine is approved for people over 18 and will normally be administered in two doses at intervals of four to 12 weeks. this it costs $ 3 to $ 4 a dose and can be stored in regular refrigerators. In comparison, the Moderna and Pfizer / BioNTech vaccines that have received emergency use authorizations in the U.S. cost between $ 15 and $ 25 per dose and require freezers. The Pfizer / BioNTech vaccine in particular needs refrigerated storage at minus 70 degrees Celsius (minus 94 degrees Fahrenheit) or less.
The Oxford / AstraZeneca vaccine also uses technology different from the Covid-19 immunizations approved so far. The Pfizer / BioNTech and Moderna vaccines use a molecule called mRNA as their platform to provide instructions for making a part of the SARS-CoV-2 virus. Oxford and AstraZeneca used a different innovative method, reprogramming another virus to transmit DNA instructions to make parts of the SARS-CoV-2 virus. Using another virus to package and distribute genetic material helps the Oxford / AstraZeneca vaccine to remain stable even at the highest temperatures.
However, Oxford and AstraZeneca found some problems with their clinical tests, including a dosing error that caused a group to receive less than the full dose in their initial injection. So far, its effectiveness appears to be less than that of the Moderna and Pfizer / BioNTech vaccines, although well above the 50 percent limit that the Food and Drug Administration and the European Medicines Agency have set for vaccine approval.
But the real value of effectiveness remains unclear, ranging between 70 percent and 90 percent effective in preventing Covid-19. And Oxford and AstraZeneca have been cautious about certain details surrounding their research.
One reason the Oxford / AstraZeneca vaccine was approved in the UK, but not in the USA, is that UK regulators evaluate clinical trial data on an ongoing basis. The FDA prefers to have more complete test data. In the USA, phase 3 clinical trials of the Oxford / AstraZeneca vaccine are still being conducted.
During a press conference on December 30, Moncef Slaoui, the scientific leader of the US government’s Operation Warp Speed, said it could take months for the US to give the green light to this vaccine. “We project, if all goes well, that reading and emergency use authorization may be granted sometime in early April,” said Slaoui.
But, as in the UK, having another vaccine available in the U.S., especially one that is cheaper and easier to store, would help control the spread of Covid-19. The US government has already invested $ 1.2 billion in the Oxford / AstraZeneca vaccine and has pledged to buy 300 million doses.