24 Britain The Economist June 4th 2022
A post-pandemic thought experimentBusiness as flusual
T
he covid-19 pandemic rumbles on. In
the week ending May 21st, one in 60
adults in Britain were estimated to be in-
fected; 16,504 people have died with the vi-
rus since February 23rd, which was when
England’s restrictive measures ended. But
only a new, more harmful variant would
prompt a return to the rules of the past.
The government’s plan is to deal with
the disease in a “similar way to other exist-
ing respiratory illnesses” such as the flu. In
practice, that means less surveillance, few-
er vaccinations and a greater willingness to
accept infections and deaths. This trade-
off seems reasonable to many (though less
so to clinically vulnerable people). But
dialling down the response to be more like
the approach to flu is not the only option.
Another would be to treat flu more like co-
vid. “There is a fatalism about flu,” says
Professor Ajit Lalvani of Imperial College
London. “Every year the winter flu season
overwhelms the nhs. Applying the lessons
learnt through covid could help.”
If ever there was a time to think differ-
ently about the disease, this is it. Epidemi-
ologists worry that two years of low expo-
sure to flu may have caused immunity to
wane to low levels. That may result in an
extraordinary number of cases this winter,
at a point when huge waiting-lists will still
clog up the National Health Service (nhs).
Before asking how things might be
done differently, start with how things
usually are. Pre-covid estimates based on
serological surveys suggest that as many as
one in five Britons contract the flu each
year. The vast majority of people get a rela-
tively mild illness but for some a trip to the
doctor will be needed. A study in 2007 esti-
mated that flu results in some 800,000 vis-
its to family doctors each year. Unlike co-
vid, it particularly affects the very young as
well as the elderly: children under 14 ac-
counted for two-thirds of visits.
If a respiratory infection worsens suffi-
ciently, treatment at hospital is needed. As
many as 40,000 people are hospitalised
each year with breathing difficulties
caused by the flu; the average total in-pa-
tient cost is £7,500 ($9,360). Because respi-
ratory infections are slow to shift, patients
stay for 11 days on average. Occupancy of
the nhs’s 100,000 hospital beds rises from
about 88% to over 95% during the winter;
flu plays a big part in that.
Official data suggest that, on average,
around 500 people died from flu each yearin the decade to 2020. But since flu infec-
tions are not systematically diagnosed,
that number is a massive undercount. To
estimate the true number of deaths from
influenza, epidemiologists model excess
winter mortality, disaggregating flu infec-
tions from cold snaps that also lead to
death. On this basis an average of 10,000
died each year from flu in the ten years to
2020; in the winter of 2014-15 as many as
29,000 died (see chart). That is fewer than
from covid, which is projected to cause
60,000 deaths this year, but hardly trivial.
Covid shows how the fight against flu
could be joined more vigorously. The first
line of defence against any virus is a vac-
cine. As everyone got used to being jabbed
during the pandemic, the proportion of ov-er-65s who got vaccinated against flu rose
to 80% in 2021, meeting the who’s target of
at least 75% for the first time. Some protec-
tions are now being withdrawn. Adults
aged between 50 and 64, and children aged
between 11 and 15, were offered a free vac-
cine during the 2021-22 flu season, but will
not be for the coming winter; Britain’s
Joint Committee on Vaccination and Im-
munisation had wanted the programme
for schoolchildren to be extended.
The next line of defence is surveillance,
to monitor infection rates and emerging
strains, and to do a better job of allocating
resources. Flu surveillance in Britain, esti-
mated to cost around £1m a year, mostly
consists of gathering influenza-like illness
data from a sample of gpsurgeries and on-
line search trends. According to Professor
John Edmunds of the London School of Hy-
giene and Tropical Medicine: “Flu surveil-
lance is like a net with massive holes in it:
nothing gets caught.”
For covid, in contrast, the Office for Na-
tional Statistics (ons) takes 75,000 swabs
each week to get a representative rate of in-
fection across the whole population, and
runs a statistical analysis to model infec-
tion rates for different groups of people.
The survey costs about £390m a year to ad-
minister and may soon be scaled back. But
even a pared-back version could test for
other respiratory viruses at little extra cost.
The pandemic also inured people to
home-testing. Lateral-flow tests (lfts) ex-
ist for influenza, as well as for covid and
other diseases, and are sometimes used by
hospitals. Making flu and covid lfts avail-
able for home use at market costs could re-
duce transmission, particularly among
those visiting high-risk people. Perhaps
one-quarter of flu deaths typically occur
among care-home residents.
Finally, the pandemic showed how rap-
id testing of promising treatments can
yield striking results. Large-scale covid
trials co-ordinated by academics at the
University of Oxford found, for example,
that a low-cost steroid, Dexamethasone,
reduced deaths by one-third among venti-
lated patients. Professor Sir Peter Horby,
who led the covid trials, says that extend-
ing these trials to evaluate treatments for
severe flu is a “no-brainer” but he has so far
not received funding to do so.
There is one big way in which the pan-
demic has made transmission of flu less
likely in the future. Among people who
have the option to work remotely, 70% told
the onsin May that they were more likely,
compared with pre-pandemic times, to
stay home if they have a cold in the future.
Those who do still struggle in are more
likely to wear masks than they were. But in
other ways, the approach to flu does not
seem likely to change markedly. There may
be good reasons for this choice but come
the winter, it may have consequences. What if the flu were treated more like covid, and not the other way round?I haven’t done a lateral-flow testThe acceptable killer
England, deaths caused by influenza, ’000
By age groupSources: UKHSA; Peabody et al., Epidemiology & Infection, 2018*Data since June 2020 not available30
25
20
15
10
5
0
2019171513112009
Years ending May*65 and over
Under 65