Here’s What Happens
Now That Oxford-AstraZeneca Vaccine Won U.K. Clearance
By Suzi Ring
December 30, 2020, 4:37 AM EST Updated on December 30, 2020,
8:46 AM EST
The U.K. approved a second Covid-19 vaccine, and it’s a
homegrown one this time. The government has ordered 100 million doses of the
shot developed by AstraZeneca Plc and the University of Oxford, more than any
other candidate.
When will the vaccination start?
The first doses are being released Wednesday and vaccination
will start next Monday. AstraZeneca says it aims to supply millions of doses in
the first quarter.
The priority should be to give as many people in at-risk
groups their first dose rather than provide the required two doses in as short
a time as possible, the government says. But people should get the second shot four to 12 weeks after the first.
The first vaccine the U.K. approved, made by Pfizer Inc. and BioNTech SE, requires two injections three weeks apart.
How will I know when it’s my turn?
The National Health
Service says it will contact people when it’s their turn to be vaccinated,
and has emphasized it’s important not to reach out before then.
How does the vaccine differ from others?
The product uses a
harmless chimpanzee virus to transport genetic material that triggers an
immune response to the coronavirus. That’s different from BioNTech and
Pfizer’s messenger RNA approach, which transforms the body’s own cells into
vaccine-making factories.
When patients were given two full doses, the Astra-Oxford
vaccine was 62% effective in an advanced trial -- less than the
Pfizer-BioNTech one and another from Moderna Inc. A small group that mistakenly received half of the first
dose showed better protection, with efficacy reaching 90%. But participants
were 55 years old or less, and
because older people who are most at risk of severe Covid-19 often show more
sluggish immune responses, the results leave some doubt as to whether the
higher efficacy will stand up to further testing.
How the Oxford-AstraZeneca Vaccine Works
The viral vector vaccine uses a harmless virus to transport
genetic material which triggers an immune response to the coronavirus
Which dosage will be used?
The U.K. will administer the vaccine in two full doses rather than the half-dose, full-dose regimen.
AstraZeneca has said it plans more clinical research to find out whether the
results of the half-dose group hold up.
Why did the U.K. order more doses of this vaccine?
The homegrown shot is easier
to transport and store: It can last six months at refrigerator
temperatures, whereas the Pfizer-BioNTech vaccine requires deep freezing. The
majority of doses will also be produced locally, which should help avoid any
supply delays.
Can I choose
which vaccine I get?
Probably not. The important thing to remember is that
both products protect against severe disease, which is the ultimate goal of the
vaccination effort.
Can I get both
vaccines?
A regulatory panel advised against mixing doses because a combination hasn’t been tested, but
it’s possible shots could be pooled in the future if studies show that can
produce an enhanced immune response.
The U.K.’s Vaccine Taskforce has outlined plans to test
combinations of approved shots next year to see if a mix could boost immunity,
the panel said this month. The first tests will combine the Pfizer and Astra
vaccines.
A combination should work for vaccines that target the spike
protein of SARS-CoV-2, according to Andrew Pollard, who led the University of
Oxford’s vaccine trial with Astra. Both vaccines, as well as the Moderna one on
sale in the U.S., use the spike protein
as a target.
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