2021-01-30_New_Scientist

30 January 2021 | New Scientist | 11

IT APPEARS that the new coronavirus
variant first identified in the UK is
slightly deadlier as well as more
transmissible than older variants.
But thanks to improved treatments,
the risk that people who are infected
will die could still be lower in the UK
than it was during the first wave
of the pandemic last March.
“The additional mortality from
the new variant is concerning,” says
Graham Medley at the London School
of Hygiene & Tropical Medicine
(LSHTM). But the main reason why so
many people are dying now in the UK
is the number of infections, he says.
“If you want to reduce the number
of deaths, you have to reduce the
incidence. That is the critical thing.”
There is now strong evidence
that the B.1.1.7 variant is around
50 per cent more transmissible
than previous variants.
Determining whether any variant
is deadlier than another is much
harder, given that there are far fewer
coronavirus-related deaths than
infections. It remains unclear whether
the P.1 variant in Brazil and the
B.1.351 variant from South Africa
are any deadlier than previous
variants. South Africa has reported

40 to 80 per cent higher mortality

in the hardest-hit regions compared

with its first wave, but attributes

this to increasing pressure on the

healthcare system.

To find out if B.1.1.7 is deadlier,

researchers looked at what

happened to around a million

people who tested positive for the

coronavirus in the UK. Of these,

around 100,000 were very likely

to have had B.1.1.7, based on tests.

The researchers compared people

infected with B.1.1.7 to matched

controls who had other variants. In

addition to matching people’s age,

sex and ethnicity, the researchers also

attempted to account for the fact that

hospitals in some areas were busier

than others and might not have been

able to provide the same level of care.

Four independent teams have now

analysed this data, in various ways.

All concluded that people infected

with B.1.1.7 have a higher risk of

dying, with two teams finding a rise

of about 30 per cent, one a 65 per

cent rise and one a 90 per cent rise.

“Any way that you do it, you get

an estimate that is very similar,” says

John Edmunds, also at the LSHTM.

Although these estimates may not

seem that similar, a coronavirus

variant could theoretically be 500

or even 5000 per cent deadlier.

A more transmissible virus is

worse than a deadlier virus, says

Edmunds. “Unfortunately, it appears

this [variant] might be both.”

While this sounds alarming, the

overall risk of dying if infected remains

low. For instance, during the first

wave, the infection fatality rate was

around 1 in 100 in high-income

countries. It is thought to have fallen

significantly since. “Treatments have

been improving,” says Peter Horby

at the University of Oxford, who

chairs the UK’s New and Emerging

Respiratory Virus Threats Advisory

Group. “That may well offset any

differences in this new variant.”

For people who have had at

least one dose of a vaccine, the

risk of dying will be even lower still.

So these findings are no cause for

panic, but they are a reminder of how

important it is that we all redouble

our efforts to avoid becoming

infected and infecting others. ❚

Paramedics unload

equipment at the

Royal London Hospital

“ We are optimistic that it

can be a really effective

way to provide surveillance

for large populations”

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Variant detection

Virus variants found

in sewage before

tests reveal them

VARIANTS of coronavirus can be
detected in wastewater long before
they are spotted by tests in people.
Those infected with coronavirus
shed it in their faeces. Hundreds
of municipalities around the world
already test wastewater for the
presence of the virus as part
of their surveillance operations.
Now research suggests they
could also check which genetic
variants are circulating to flag up

potentially dangerous new versions.

Kara Nelson at the University

of California, Berkeley, and her

colleagues recently extracted useful

sequence information from San

Francisco’s sewage. Another team,

led by Niko Beerenwinkel at ETH

Zurich, detected the genome of the

B.1.1.7 coronavirus variant – first

seen in the UK – in Swiss sewage

sampled in mid-December, two

weeks before the first confirmed

case of the variant in Switzerland.

“We’ve demonstrated it can work

and are now trying to apply it at

larger scales,” says Nelson. Working

with the California Department of

Public Health, her team hopes to

have a wastewater sequencing

system running in four weeks.

The virus is diluted in wastewater

but is detectable if more than 1 in

1000 people are shedding it, says

Sharon Peacock at the COVID-

Genomics UK Consortium. That is

a relatively low infection rate: parts

of the UK have recently seen rates of

about 1 in 30. The UK does sewage

surveillance for coronavirus and is

working on adding sequencing

capabilities to it, says Peacock.

Wastewater monitoring has

the added advantage of sampling

everyone who uses the sewage

system, not just those who turn up

for a test or treatment. That includes

asymptomatic carriers who may

be spreading new mutants.

“We are very optimistic that it can

be a really efficient and effective

way to provide surveillance for

large populations,” says Nelson.

It could be very useful in low-income

countries that don’t have the

capacity or funds for mass testing. ❚

Graham Lawton

Analysis Viral spread

Is the new UK variant more deadly as well as spreading faster?

Evidence is mounting that the variant first detected in the UK is more

lethal, but there is no need to panic, reports Michael Le Page