16 January 2021 | New Scientist | 9come back for their second shot.
“The longer you leave it, the more
time there is for people to forget,”
says Deborah Dunn-Walters at the
University of Surrey, UK, who is
chair of the British Society for
Immunology’s covid-19 task force.
The change also raises ethical
issues for the people who were
given the first dose on the
understanding that the second
would follow three weeks later
as per the trial data.
Overall, it is possible that the
shift, and the controversy around
it, will undermine confidence
in the vaccine programme.
The scientific community
is divided on the question
of whether the UK strategy
is a good one. The US Food and
Drug Administration said in
a statement that changes in
vaccine administration could
place “public health at risk”.
Legal issues
The answer may depend on
whether you take the perspective
of an individual or think of the
whole population. Much of the
backlash has come from the US,
where overall public health has a
lesser role in the medical system.
The US is also more litigious
than the UK, says Evans. Someone
in the US who catches covid-
two months after their first
vaccine shot could sue their doctor
for delaying the second dose. But
a doctor can’t be held responsible
by infected people if they haven’t
yet received a vaccine at all.
The British Society for
Immunology’s covid-19 task force
had initial concerns about the
changes to the dosing schedule,
and sought more information
from England’s chief medical
officer about the evidence. In
the end, the society put out a
statement backing the decision.
There is great variance between countries in how many doses of
vaccines have been given to people so far. The total number of doses
administered is shown here for selected countries, which may not equal
the total number of people vaccinated, because multiple doses of some
vaccines are neededA separate criticism of the UK
programme is that it supports
giving people a different vaccine
for their second dose from the
one they received initially, in a
mix-and-match strategy. Critics
of the tactic include John Moore
at Cornell University in New York,
who has said that by doing this
the UK is “abandoning science”.
The move is less controversial
than it appears. The UK has
only said that vaccines could be
mixed if someone was due to
receive their second shot and
there is no matching vaccine
available, or if it is unknown
which type they got initially.
Mixing the shots might even
give better immunity. Previous
work on other vaccines suggests
that injecting someone with the
same virus proteins in a different
package provokes a stronger
immune response. Known as
a “prime-boost” strategy, it has
been investigated in vaccines
against HIV and malaria.
The debate rolls on, but the
UK may not be an outlier for long.
Last week, Denmark approved a
delay of up to six weeks between
the first and second shots of
vaccine, and the German health
ministry is debating a longer wait
still, according to media reports.
“There’s still quite a bit of debate,
although I feel there’s a tilt
towards a more flexible
schedule,” says Leif Erik Sander
at Charité – Berlin University
of Medicine, who has argued
for a delay between doses.
Even if the change to a delayed
schedule isn’t ideal because it
deviates from the time periods
that were tested in the vaccine
trials, the decision needs to be
taken in the context of the
pandemic, says Dunn-Walters.
“We had to get over ourselves and
take a pragmatic view,” she says.
“We are in an emergency.” ❚ImmunisationsVaccine roll-out
around the world
Covid-19 vaccine doses administered
per 100 people
The total number of individual vaccine doses given per 100 people (only
selected countries shown). This may not equal the total number of people
vaccinated because multiple doses of some vaccines are neededIsrael 21.38 (11 Jan)
United Arab Emirates 11.8 (11 Jan)
UK 3.94 (11 Jan)
US 2.72 (11 Jan)
Denmark 2 (10 Jan)
Italy 1.16 (11 Jan)
Spain 0.87 (11 Jan)
Canada 0.85 (10 Jan)
Germany 0.73 (10 Jan)
Poland 0.
Romania 0.65 (11 Jan)
China 0.63 (9 Jan)
Russia 0.55 (2 Jan)
Saudi Arabia 0.51 (11 Jan)
Argentina 0.24 (8 Jan)
France 0.21 (11 Jan)
Mexico 0.07 (11 Jan)
SOURCE: OURWORLDINDATA.ORG/COVID-VACCINATIONS • CC BY