Science - 16.08.2019

NEWS | IN DEPTH

628 16 AUGUST 2019 • VOL 365 ISSUE 6454 sciencemag.org SCIENCE

PHOTO: REUTERS/BAZ RATNER

but “we are not yet where we need to be.”
Ovabrite, a U.S company in Austin, is
chasing a technique that would leave the
eggshell intact and sort eggs before incu-
bation. Mass spectrometers would capture
and analyze sex-specific volatile molecules
that leak through the eggshell. Scientists
suspect the molecules, first discovered in
quail eggs, may allow parent birds to smell
clues about an embryo’s development and
sex. But it is still a challenge to reliably
detect such a faint signal from preincuba-
tion eggs, which must be refrigerated, says
Ovabrite President Jonathan Hoopes.
Some predict that genetic engineering
could help do away with complicated ro-
bots. Groups in Australia and Israel have
used the CRISPR gene-editing technique to
modify hens’ sex chromosomes so that their
sons carry a marker gene that makes male
eggs glow under fluorescent light. That
would allow hatcheries to sort out the fluo-
rescent male eggs with a simple detector.
Finding a marker that produces a strong
enough signal in early embryos is a chal-
lenge, says Yehuda Elram, CEO of eggXYt
(pronounced “exit”) in Jerusalem. He says
eggXYt has found a solution, but declined
to say whether it is close to hatchery tests.
Public opposition to genetic modifica-
tion in Europe means the approach is un-
likely to catch on there. But Mark Tizard, a
geneticist at the Australian Animal Health
Laboratory in Geelong, who is also work-
ing on the technology, says his group’s so-
cial science research suggests consumers in
North America and Australia might accept
it. Neither the layer hens nor the eggs sold
for consumption would contain modified
genes, because only males carry the in-
serted marker gene, he notes.
Other noninvasive ideas are still in the
running: Scientists in Turkey reported that
with the help of machine learning they
could detect subtle differences between
male and female egg shapes. German re-
searchers have examined MRI scans of in-
tact eggs for sex differences.
Meanwhile, the political pressure con-
tinues. In June, a German court ruled that
culling day-old chicks violates the country’s
laws against killing animals without a justi-
fiable reason. The court allowed hatcheries
an exception “until a feasible alternative is
available,” but politicians are still consider-
ing a law to ban culling.
Researchers, feeling they are close to
commercial breakthroughs, don’t want that
to happen—yet. “A ban now would do more
harm than good,” Einspanier says—mostly
by driving hatcheries to neighboring coun-
tries with less strict laws. With a bit more
time, she says, her field should be able to
finally crack the problem. j

I

n 2006, two survivors of an Ebola out-

break 11 years earlier in Kikwit, Demo-

cratic Republic of the Congo (DRC),

were flown to the National Institute of

Allergy and Infectious Diseases (NIAID)

in Bethesda, Maryland. There, scientists

drugs, whereas the use of the other two ex-

perimental therapies will be discontinued,

researchers said at a 12 August press con-

ference where the results were announced.

“This will undoubtedly save lives,” Jeremy

Farrar, head of the Wellcome Trust in

London—which was not involved in the

study—said in a statement. Mike Ryan,

executive director of the Health Emergen-

cies Programme at the World Health Organi-

zation (WHO) in Geneva, Switzerland, calls

the news “fantastic.”

The findings should help allay the sus-

picion and fatalism with which many DRC

citizens view the Ebola response, Congolese

virologist Jean-Jacques Muyembe-Tamfum

said at the press conference. “People think

that if you enter a treatment center, you’ll

leave in a coffin,” said Muyembe, who heads

the DRC’s National Institute for Biomedical

Research in Kinshasa, a partner in the trial,

and took command of the Ebola fight on

22 July (Science, 9 August, p. 526). Now, “We

have a great message,” Muyembe said: “A

treatment center is a place where you can

recover and that you leave alive.”

So far, no drugs exist for Ebola; in the cur-

rent outbreak, centered in the eastern DRC,

67% of all known cases have died. Scientists

tested several drugs during the West African

Ebola epidemic of 2013–16, but none proved

Successful Ebola treatments

promise to tame outbreak

Antibody preparations that cut the death rate dramatically

will become available to all patients in Congo

INFECTIOUS DISEASES

By Kai Kupferschmidt

A health worker puts on protective gear at an Ebola treatment center in Beni, Democratic Republic of the Congo.

took blood samples and from one of the pa-

tients isolated what might be the secret to

his survival: a potent antibody against the

virus, which they named mAb114. Now, in

the DRC’s latest and largest Ebola outbreak,

mAb114 and another monoclonal antibody

preparation, REGN-EB3, have yielded

something unprecedented for people in-

fected with the deadly virus: hope.

In November 2018, 3 months into the

current outbreak, researchers started a

trial using mAb114 and two other potential

treatments for people infected with Ebola;

1 month later, they added a fourth treat-

ment, REGN-EB3, developed in mice with

“humanized” immune systems by scientists

at Regeneron Pharmaceuticals in Tarrytown,

New York. Last week, that study was stopped

early after an interim analysis showed that

both mAb114 and REGN-EB3 boost patients’

chance of survival dramatically.

All patients at Ebola treatment centers in

the DRC will now receive one of these two