The Economist - UK (2022-03-19)

TheEconomistMarch19th 2022
Graphic detail Malaria

81

Anothervaccine

victory?

W

henitcomestocovid­19vaccines,
poor  countries  in  Africa  have  been
stuck  at  the  back  of  the  queue.  However,
the  continent’s  long  wait  for  another  im­
munological  miracle  appears  to  be  draw­
ing  to  a  close.  Later  this  year,  the  world’s
first malaria vaccine is scheduled for a roll­
out.  Although  the  current  version  leaves
much to be desired—it requires four doses,
is hard to manufacture at scale and reduces
severe infections by a mere 30%—better al­
ternatives may be on the way. A jab devel­
oped  by  scientists  at  Oxford  has  shown
77% effectiveness. If clinical trials go well,
they  aim  to  apply  for  pre­qualification
from  the  World  Health  Organisation  in
September.  Production  at  a  rate  of  up  to
200m doses per year could follow swiftly.
Malaria has proved to be a stubborn ad­
versary. In mosquito­rich environments, it
is  5­20  times  more  contagious  than  the
Omicron  variant  of  sars­cov­2.  The  dis­

easewasonceendemicacrossmostofthe

world,  sweeping  through  the  Americas  in

the 1600s and reaching as far north as Rus­

sia’s Arctic coast and as far east as Japan.

Past efforts to defeat malaria using vac­

cines  have  failed,  largely  because  the  life

cycle  of  the  parasite  that  causes  it  has  12

stages. Each presents a different target. In­

stead,  rich  countries  in  cool  regions  have

eradicated  the  disease  by  attacking  the

mosquitoes that spread it, both by spraying

insecticides  and  by  destroying  breeding

grounds.  Poorer,  tropical  countries  have

fared worse. In 2020 malaria killed 627,000

people, of whom 96% lived in Africa.

New vaccines are just one element of a

three­pronged strategy to vanquish malar­

ia.  Some  tried­and­true  tools,  like  install­

ing  insecticide­impregnated  bed  nets  and

distributing  therapeutic  drugs,  can  still

reach  more  people.  Another  scientific  ad­

vance could prove even more valuable than

vaccines: genetically modified mosquitoes

that  cannot  reproduce  sustainably,  which

could cause the insects that spread the dis­

ease  to  die  out.  Such  “gene  drives”  could

damage ecosystems, and a regulatory pro­

cess needs to be set up before they can be

approved.  But  big  donors  like  the  Gates

Foundation support them. Modellers at the

London  School  of  Hygiene  and  Tropical

Medicine reckon that, with enough re­

sources, by 2030 these tactics could jointly

cut deaths caused by malaria by 75%.

Partly  because  Africa’s  population  is

growing  so  fast,  when  projected  into  the

future such gains would have a remarkable

impact.  By  2034  the  annual  number  of

deaths  averted  would  exceed  the  current

yearly toll from breast cancer. In total, 20m

lives would be saved during the next three

decades—the  same  number  as  The Econo-

mist’s  estimate  of  the  global  increase  in

deaths during the covid­19 pandemic. And

measured in years of life, this effect would

dwarf  covid’s.  Whereas  covid  mainly  kills

the elderly, around 80% of those felled by

malaria are aged five or younger.

The economic benefits are nearly as im­

pressive. On average, adults who catch ma­

laria  lose  three  days  of  work.  Cutting  the

number  of  cases  by  75%  would  yield  14bn

extra  workdays  over  two  decades,  the

equivalent  of  the  current  annual  labour

supply of Nigeria. Productivity might also

improve,  since  non­fatal  cases  of  malaria

in  children  can  stunt  growth  and  hinder

cognitive  development,  in  part  by  induc­

ing  comas.  A  hidden  factor  holding  back

economic growth inAfrica may be the last­

ing  impact  of  thedisease  on  survivors—

call it “long malaria”.n

Squashing malaria could save as many
lives as covid-19 has taken

0.9m

0

0.3m

0.6m

1.2m

2000 10 20 30 40 50

19.4mlives

2020 2050 2020 2050

23.1bn days

14.2bndaysworked

inNigeriain 2020

17.9mdeathsfrom

cardiovasculardisease

globallyin 2021

→ A big push to fight malaria could save nearly 2m lives over the next three decades

Annual deaths from malaria Malaria* incidence per 1,000 people, 2019

Witha 75%dropinmalariaincidence

Totaldeathsaverted Total workdays gained

*Plasmodiumfalciparum Sources:Malaria Atlas Project; Our World in Data; UN; WHO; World Bank; The Economist

↓ 2000-19
Better drugs, more accurate
diagnoses and more bed nets
reduce malaria deaths by 37%

↓ 2020-22

Covid-19disruptsanti-malaria

efforts,asmedicalresourcesare

divertedtofightthepandemic

↑2020-30baselinescenario

If theinfectionrateremains

constant,populationgrowthwill

causethedeathtolltorise

↓2020-30“bigpush”scenario

Infectionratefallsby75%from215 to 23,

thankstovaccines,geneticallymodified

mosquitoesandbetteruseofexisting tools

Nigeria

Congo

Uganda

Mozambique

Rest of sub-

Saharan Africa

Rest of world Deaths averted

50

250

500

Mozambique

Uganda

Congo

Nigeria