The UK has approved a second COVID-19 vaccine for use in that country, and this time it is homemade. The government has ordered 100 million doses of the injection developed by AstraZeneca and the University of Oxford, more than any other candidate.
When will vaccines start?
The first doses are being released in the UK on Wednesday, and the vaccination campaign will start on Monday. AstraZeneca says it intends to supply millions of doses in the first quarter.
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1:53 pm, December 30, 2020An earlier version of this story said that the vaccine made by Pfizer and BioNTech turned the cells into vaccine factories. The vaccine stimulates cells to create a piece of the coronavirus to stimulate an immune response.
The government says the priority should be to give the first dose to the largest number of people in risk groups, rather than providing the two necessary doses in the shortest possible time. But people should receive the second injection four to 12 weeks after the first.
The first vaccine approved by the United Kingdom, made by Pfizer Inc. and BioNTech, requires two injections three weeks apart.
How does the vaccine differ from others?
The product uses a harmless chimpanzee virus to carry genetic material that triggers an immune response to the coronavirus. This is different from the messenger RNA approach used by Pfizer and BioNTech and another vaccine made by Moderna that has been authorized for use in the United States. These vaccines stimulate the body to produce a protein on the surface of the coronavirus, which in turn stimulates the immune system to produce antibodies. , which turns the body’s own cells into vaccine factories.
When patients in a clinical trial received two full doses of the Astra-Oxford vaccine, it was 62% effective – less than the Pfizer-BioNTech and Moderna vaccines.
A small group that mistakenly received half a dose in the first injection had better protection, with an effectiveness reaching 90%. But the participants were 55 or younger, and since older people who are most at risk for severe cases of COVID-19 generally have a slower immune response, the results leave doubts as to whether the higher efficacy will stand up to further testing.
What dosage will be used?
The UK will administer the vaccine in two full doses, instead of the half dose and full dose regimen. AstraZeneca said it plans more clinical research to find out if the half-dose group’s results hold up.
Why did the UK ask for more doses of this vaccine?
The Astra-Oxford injection is easier to transport and store: it can last six months in refrigerator temperatures, while the Pfizer-BioNTech vaccine requires deep freezing. Most doses will also be produced in the UK, which should help to avoid delays in delivery.
Will the UK allow people to get both vaccines?
A regulatory panel advised against mixing different vaccine doses because this combination has not been tested. But it is possible that the injections could be combined in the future if studies show that this can produce an enhanced immune response.
The UK’s Vaccine Taskforce outlined plans to test combinations of injections approved next year to see if a mixture could boost immunity, the panel said this month. The first tests will combine the Pfizer and Astra-Oxford vaccines.
A combination should work for vaccines that target the SARS-CoV-2 spike protein, according to Andrew Pollard, who led the Oxford University vaccine test with AstraZeneca.