Science News - 16 July 2022

44 Pages·2022·12 MB·English

A ‘Radar’ for Dark Matter | COVID-Sniffing Dogs Are Up to Snuff
MAGAZINE OF THE SOCIETY FOR SCIENCE s JULY 16, 2022 & JULY 30, 2022
TARDIGRADE
TOUGH
This microscopic animal may teach us
how to withstand the rigors of outer space
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VOL. 202 | NO. 2
Features
Moving Past Paralysis
18
Methods that stimulate the spine with electrodes could improve
the lives of people living with spinal cord injuries — including in
ways that extend well beyond walking. By Laura Sanders
Live Wires
24
Cable bacteria are living electrical conduits that may help
clean up oil spills and cut methane emissions. By Nikk Ogasa
What Makes Tardigrades So Tough?
30
COVER STORY The animals amaze and delight with their tiny
physiques and extreme survival skills. By Douglas Fox
It’s the Climb
32
Sociologist Demond Mullins scales mountains to encourage
Black people and veterans to experience the outdoors.
24
By Melba Newsome
News
6 Misunderstandings about 10 A galaxy in the early Gravitational waves
pregnancy biology cloud universe has a surprising might someday help
D
N
A U.S. abortion debates ratio of gas to stars map dark matter
NL 4
E
GRE 8 A second bout of 11 A mystery Milky Way 13 As sea ice dwindles, some
G
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ANS common neutron star 2 EDITOR’S NOTE
CE 14 Wildfires have scorched
O
ASA 9 Scientists add coronavirus 12 Quantum computing Earth for at least 4 NOTEBOOK
N
N/ infections to the list of may have benefits for 430 million years, fossil A robotic finger dons living
E
ANS things dogs can detect machine learning evidence suggests human skin; clumsy frogs
H
O
W. J Scientists spot signs of can blame their inner ears
MAS a neutron quartet 36 REVIEWS & PREVIEWS
O
H
T New books explore
HI; 15 To escape predators,
UC animal senses and our
E some butterflies might
AK relationship with viruses
RD; S. T shed their wing tails 39 FEEDBACK
AA 16 Black Death bacteria
G
AM may have originated in 40 SCIENCE VISUALIZED
D
RIIS Central Asia How a famous painting’s
ARS rose lost its brilliance
N, L 17 The world’s largest
E
ARS known bacterium is COVER Tardigrades are
EN L visible to the naked eye found in moist, green
EFF places, hence the fitting
P: ST Catnip’s insect-repelling nicknames water bear
TO powers get a boost from and moss piglet. Eye of
OM 13 Science/Science Source
R leaf-crushing felines
F
www.sciencenews.org | July 16, 2022 & July 30, 2022 1
EDITOR’S NOTE
We won’t shy away from PUBLISHER Maya Ajmera
EDITOR IN CHIEF Nancy Shute
EDITORIAL
covering politicized science EDITOR, SPECIAL PROJECTS Elizabeth Quill
NEWS DIRECTOR Macon Morehouse
DIGITAL DIRECTOR Demian Perry
FEATURES EDITOR Cori Vanchieri
In this issue, we report on the science of pregnancy MANAGING EDITOR, MAGAZINE Erin Wayman
DEPUTY NEWS EDITOR Emily DeMarco
biology and how it has been misunderstood or misap- ASSOCIATE NEWS EDITORS Christopher Crockett,
Ashley Yeager
plied in policies and laws regulating abortion (Page 6). We ASSOCIATE EDITOR Cassie Martin
ASSOCIATE DIGITAL EDITOR Helen Thompson
posted the article on our website on June 24, the day the AUDIENCE ENGAGEMENT EDITOR Mike Denison
CIVIC SCIENCE FELLOW Martina G. Efeyini
U.S. Supreme Court ruled that the right to an abortion is ASTRONOMY Lisa Grossman
BEHAVIORAL SCIENCES Bruce Bower
not protected by the Constitution. BIOMEDICAL Aimee Cunningham
EARTH AND CLIMATE Carolyn Gramling
Covering one of the most consequential and controversial rulings in the court’s LIFE SCIENCES Susan Milius
MOLECULAR BIOLOGY, SENIOR WRITER Tina Hesman Saey
history may seem off topic for a science magazine. But Science News has covered NEUROSCIENCE, SENIOR WRITER Laura Sanders
PHYSICS, SENIOR WRITER Emily Conover
politically and ethically contentious issues since our founding in 1921. Our found- SOCIAL SCIENCES Sujata Gupta
STAFF WRITERS Erin Garcia de Jesús, Nikk Ogasa, Meghan Rosen
ers, zoologist William E. Ritter and newspaper magnate E.W. Scripps, thought it EDITORIAL ASSISTANT Aina Abell
SCIENCE WRITER INTERNS Anil Oza, Asa Stahl
essential that Americans have accurate information about science so that they can CONTRIBUTING CORRESPONDENTS
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understand the world around them and be informed citizens.
DESIGN
We have stayed true to that mission over the decades, reporting on science CHIEF DESIGN OFFICER Stephen Egts
DESIGN DIRECTOR Erin Otwell
to inform public debate on a wide range of issues including abortion, racism, SENIOR ART DIRECTOR Tracee Tibbitts
ART DIRECTOR Chang Won Chang
nuclear weapons and nuclear power, HIV/AIDS, poverty, pollution, gun violence SCIENCE NEWS FOR STUDENTS
and climate change. We have also explained where science has been manipulated MEDAITNOARG IJNaGn eEtD RITaOloRf fAND EDITOR, SCIENCE NEWS EXPLORES
or misapplied in the service of political agendas. And we have covered the rise Sarah Zielinski
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of antiscience misinformation and disinformation on subjects including climate ASSISTANT EDITOR Maria Temming
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change, vaccines and the pandemic (SN: 5/8/21 & 5/22/21, p. 22). EDITORIAL ASSISTANT, SCIENCE NEWS EXPLORES Aaron Tremper
Looking specifically at abortion, Science News has covered the subject consis- SPROECSIIDEETNYT FAONDR CSECOI EMNaCyaE A jmera
tently, including a 1937 study in JAMA that found abortion to be common among CCHHIIEEFF FOIPNEARNACTIIANLG O OFFFFICICEERR M Raatcth Feul lGleorl d man Alper
married women in New York City who use birth control, with 1 in 8 such women CCHHIIEEFF, P ERVOEGNRTAS MAN ODF FOIPCEERRA MTIiOchNeSl eC Gailtid Gdoelnd berg
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2 SCIENCE NEWS | July 16, 2022 & July 30, 2022
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NOTEBOOK
Excerpt from the
July 22, 1972
issue of Science News
Living human skin covering a
50 YEARS AGO robotic finger can bend with the
finger (shown) and self-heal.
What did in
the dinosaurs?
HOW BIZARRE
Dinosaurs might have been A robotic finger’s living skin heals like the real thing
endothermic, or warm-
blooded…. The combination The Terminator may be one step closer to dermis, covering the finger. The team
of large size, endothermy reality. then poured a liquid containing human
and naked skin may explain Researchers at the University of Tokyo keratinocyte cells onto the finger, which
the extinction of dinosaurs. have built a robotic finger that, much like formed an outer skin layer, or e pidermis.
About 65 million years ago Arnold Schwarzenegger’s titular cyborg After two weeks, skin covering the
there was a sharp drop in assassin, is covered in living human skin. finger measured a few millimeters
temperature…. Dinosaurs, The goal is to someday build robots that thick — comparable to the thickness of
lacking skin insulation and look like real people — albeit for more human skin.
too large to burrow under- altruistic purposes. The lab-made skin was strong and
ground … could not survive. Super realistic–looking robots could stretchy enough to withstand the
Meanwhile, evidence has more seamlessly interact with humans in robotic finger bending. It could also heal
come that … the shells [of medical care and service industries, say itself: When researchers made a small
their eggs] became progres- biohybrid engineer Shoji Takeuchi and cut on the robotic finger and covered
sively thinner … too fragile to his colleagues June 9 in Matter. (Whether it with a collagen bandage, the skin’s
support the growing embryo. cyborgs masked in living tissue would be fibroblast cells merged the bandage
congenial or creepy is probably in the eye with the rest of the skin within a week.
UPDATE: Some dinosaurs may of the beholder.) “This is very interesting work and an
have been warm-blooded and To cover the finger in skin, Takeuchi important step forward in the field,” says
some could have laid soft- and colleagues submerged the robotic Ritu Raman, an MIT engineer who also
shelled eggs (SN: 7/12/14, p. 6). digit in a blend of collagen and human skin builds machines with living components.
But neither trait led to the rep- cells called dermal fibroblasts. The mix- “Biological materials are a ppealing
tiles’ demise. In the late 1970s, ture settled into a base layer of skin, or because they can dynamically sense
geologists proposed that an and adapt to their environments.” For
asteroid strike triggered a mass instance, she’d like to see a future ver-
extinction (1/25/92, p. 56), sion of the living robot skin embedded
killing more than 75 percent with nerve cells to make robots more
of life on Earth. That theory is aware of their surroundings.
now widely accepted. Scientists But a robot can’t wear this lab-grown
have even found the killer’s skin suit around town just yet, Raman
calling card: a crater about notes. The skin-covered robotic finger
180 kilometers wide on the spent most of its time soaking in sugar,
coast of the Yucatán Peninsula amino acids and other ingredients that
in Mexico. The asteroid prob- skin cells need to survive. A cyborg
ably crash landed there in the wearing this skin would have to bathe CHI
U
E
springtime 66 million years ago, often in a broth of nutrients or use AK
T
fossils hint (SN: 3/26/22, p. 8). This robotic finger spent much of its time in a some other complex skin care routine. H: S.
nutrient bath to keep its skin suit healthy. — Maria Temming BOT
4 SCIENCE NEWS | July 16, 2022 & July 30, 2022
MYSTERY SOLVED
Why pumpkin toadlets are clumsy jumpers
Some frogs just can’t stick the landing. he hopped on a plane to
After launching into a leap, pump- study the animals with his
kin toadlets careen through the air as colleagues in Brazil. Small
if flung from a toddler’s fist. They roll, enough to fit on a person’s
cartwheel or backflip and then plummet thumbnail, the frogs are tricky
to the ground, often belly flopping or to find in the wild. Scientists listen
crash-landing on their backs. for the amphibians’ high-pitched,
“I’ve looked at a lot of frogs, and these buzzy calls and then scoop leaf litter
are the weirdest things I’ve ever seen,” into a bag, hoping to find a few toadlets.
says Richard Essner Jr., a vertebrate In the lab, the team used high-speed Brachycephalus frogs from Brazil can leap into
zoologist at Southern Illinois University video to record more than 100 tiny frog the air but have trouble landing.
Edwardsville. jumps. The klutzy tumbles suggested
Essner and colleagues propose an that the toadlets have trouble orienting fluid to flow freely, Essner says. That
explanation for why the tiny frogs are themselves in space. means the frogs probably can’t sense
such clumsy jumpers: The animals Typically, fluid sloshing through bony how they’re twirling through the air,
lack the proper gyroscopic equipment tubes in the inner ear helps vertebrates making it tough to prep for landing.
to sense small changes in rotation, sense their body’s position. CT scans It’s possible that bony back plates
the team suggests June 15 in Science revealed that the frogs’ tubes are the offer some crash protection, but the
Advances. smallest ever recorded for adult ver- animals may stay mostly grounded for
When Essner saw videos of tebrates. Studies of other tiny animals safety (SN: 4/27/19, p. 16). As Essner
B rachycephalus frogs’ awkward aerial suggest that the tubes don’t work so observed, the frogs are “almost always
maneuvers, he was so shocked that well in miniature. It’s difficult for the crawling really slowly.” — Meghan Rosen
Friction determines how fast a row of INTRODUCING
dominoes falls, new research shows.
Lasers help physicists see
‘smoke rings’ in a new light
Doughnut-shaped structures called vortex rings are
sometimes seen swirling through fluids. Smokers can form
them with their mouths, volcanoes can spit them out dur-
THE EVERYDAY EXPLAINED ing eruptions and dolphins can blow them as bubble rings.
Friction is key for falling dominoes Now, scientists can create the rings with light.
A standard vortex is an eddy in a liquid or gas. Imagine
US Domino research may seem like fun and games, but under- taking that swirling tunnel, stretching it out and bending it
PL
ES standing how the tiles topple isn’t child’s play. “It’s a problem into a circle and attaching it end to end. That’s a vortex ring.
G
MA that is so natural; everybody plays with dominoes,” says David These rings travel through the liquid or gas as they swirl.
Y I
TT Cantor, a researcher at Polytechnique Montréal. So Cantor and For example, smoke rings float through the air away from a
E
ES/G physicist Kajetan Wojtacki of the Polish Academy of Sciences smoker’s head. In the new vortex rings, described June 2 in
G
A in Warsaw set out to simulate a row of dominoes collapsing in Nature Photonics, light behaves similarly: The flow of energy
M
O I a chain reaction. Friction is crucial for determining the speed swirls as the ring moves.
OJ
D/ at which the collapse cascades, the pair reports in the June Optics researcher Qiwen Zhan and colleagues started
U
A
RR Physical Review Applied. Toppling cascaded quickest for closely from a vortex tube, a hurricane-like structure they already
A
B
N spaced dominoes that had little friction between them and that knew how to create using laser light. The team used optics
ARTI stood on a high-friction surface. Less friction between the tiles techniques to bend the tube into a ring.
M
O; means less energy is lost. And more friction between the domi- The light rings aren’t that different from smoke or
R
EI
B noes and the surface means that the tiles don’t slide too far bubble rings, says Zhan, of the University of Shanghai for
RI
Z F. backward as they fall, which would otherwise slow the cascade. S cience and Technology. Further study might help sci-
UI
P: L In some simulations, tiles spaced far apart on a slippery surface entists better understand how the geometry of rings and
O
M T backslid so much that the cascade stopped short. Turns out, similar shapes affects light and its interaction with matter.
O
R there’s serious science behind the spectacle. — Emily Conover — Emily Conover
F
Watch pumpkin toadlets jump at bit.ly/SN_FrogFail www.sciencenews.org | July 16, 2022 & July 30, 2022 5
News
BODY & BRAIN
Misconceptions cloud abortion debate
Key aspects of pregnancy biology are often misunderstood
BY LAURA SANDERS being able to survive outside of the uterus simplest way for medical professionals to
When the U.S. Supreme Court overturned or not — are scarce or nonexistent. date a pregnancy.
Roe v. Wade on June 24, the highest court “There aren’t these set black-and-white That timeline means that an abortion
in the country shifted decisions about a points for much of this,” says obstetrician- ban that takes effect at around six weeks,
person’s right to reproductive medical care gynecologist Nisha Verma, a fellow with like the one enacted in Texas, occurs ear-
to individual state and local governments. the American College of Obstetricians lier in pregnancy than many people think,
Without the federal protections pro- and Gynecologists in Washington, D.C. Verma says. In 2020, she surveyed peo-
vided by the 1973 landmark Roe v. Wade Here’s what’s known about five key ple in Georgia, where she was practicing
decision, many states are expected to fol- aspects of pregnancy biology that often medicine, about their understanding of
low the actions of Texas and others that come up in abortion debates. the timing. “Some people will say the six
have already curtailed abortion access. weeks is after your first missed period,”
Many of those legislative efforts invoke The early timeline of a pregnancy she says. “Some people think it’s from the
medical and scientific language in an is easy to misunderstand date of conception.” Neither is correct.
effort to define when life begins. Heart How dates of a pregnancy are determined The ban would start four weeks after
development, fetal pain and viability have is supremely confusing. The standard fertilization. Counting back, that’s two
all been brought into justification for pregnancy clock actually starts ticking weeks after a missed period, which is
abortion restrictions. But many of these before a sperm cell encounters an egg, often a person’s first indication that they
rationales don’t line up with the biology two weeks before, on average. An ovary might be pregnant. Such bans leave very
of early development. Texas’ 2021 “heart- releases an egg around day 14 of an aver- little time — two weeks after a missed
beat law,” for instance, bans abortion after age 28-day menstrual cycle (SN: 6/19/21, period — to access an abortion.
about six weeks when heart cells purport- p. 16). Day one is the first day of menstru- What’s more, these dates are based
edly begin thumping. At that early stage of ation; day one is also when a pregnancy on averages. Many women have irregu-
pregnancy, there isn’t yet a fully formed officially begins in the month an egg is lar menstrual cycles. Birth control isn’t
heart to beat. fertilized. 100 percent effective, and certain types
Like most aspects of biology, early That means that when a sperm fertil- can eliminate menstruation altogether,
human development involves many izes an egg, a person is already officially throwing even more uncertainty into the
complex processes. Despite the rhetoric two weeks pregnant. As nonsensical as early timeline of pregnancy.
around these issues, clear lines — between that sounds, using the first day of an
having a heart and not having a heart, or individual’s last menstrual period is the Pregnancy requires more than
a sperm meeting an egg
On June 14, security fencing surrounded the U.S. Supreme Court in anticipation of crowds Fertilization — the process in which the
gathering in response to the decision on the case challenging Roe v. Wade.
sperm and egg fuse and mingle their
genetic contents, creating what’s known
as a zygote — usually takes place in one of
the two fallopian tubes near the ovaries.
That fertilization does not automatically
lead to a pregnancy, says obstetrician
and gynecologist Jonas Swartz of Duke
University School of Medicine. “Equating
them doesn’t make sense from a medical
standpoint.” Up to 50 percent of fertil- GES
A
M
ized eggs do not implant in the uterus, Y I
T
researchers have estimated. ET
G
A
The genetic material needs to combine VI
P
in the right way. The growing ball of cells AF
DS/
needs to travel to the uterus and implant OL
N
itself in the right spot. And the right bal- EY
R
ance of hormones needs to be churned NI
A
out to support the pregnancy. “There TEF
S
6 SCIENCE NEWS | July 16, 2022 & July 30, 2022
are so many things other than the sperm By the numbers Reported U.S. abortions in 2019 by pregnancy week
In 2019, roughly 250,000
meeting the egg that actually matter for
490,000 abortions
this to become a pregnancy that has a were reported to ns 200,000
cShanadnoceva tl,o a dne ovbeslotept rfiucriathne arn,” ds agyysn eSceolilnoa- tDhiese Ua.sSe. CCeonntterrosl faonrd bortio 150,000
Prevention with data a
gist who specializes in complex family on gestational age. of
r 100,000
planning at the University of California, Most of those abor- e
b
tions happened very m
San Diego. u 50,000
early in pregnancy. N
Lawmakers in some states are con-
SOURCE: K. KORTSMIT ET AL/
sidering abortion rules that apply to a MMWR 2021 0 ≤6 7–9 10–13 14–15 16–17 18–20 ≥21
fertilized egg. That includes fertilized eggs Weeks of pregnancy
that lodge in the wrong spot, the fallo-
pian tube, for example. Called an ectopic true at the same time: “It can be exciting fetus could survive outside of the uterus.
pregnancy, it can lead to life-threatening for a patient. It also isn’t a scientific thing.” The problem is that one clear cut-off
medical emergencies when the grow- does not exist.
ing tissue ruptures the tube and internal Fetal pain is difficult to define “That has been a moving line as science
bleeding ensues. “These are pregnancies A bit of biology that’s often used to restrict has advanced and our ability to support
that under no circumstance can become abortions is the claim that fetuses, which very small babies has advanced,” Swartz
a healthy pregnancy,” Sandoval says. “In form at week 11 of pregnancy, feel pain. says. “But it’s also not a fixed line for
fact, if they aren’t treated and continue to “Pain is very complex,” Swartz says. “It babies born now.”
grow, they will kill the patient.” Laws that requires not just a physical response, but On average, babies born around 22 to
apply to a fertilized egg could “limit our the ability to suffer as a result.” 24 weeks gestation either don’t survive or
ability to treat patients for ectopic preg- Knowing what a fetus experiences is they survive with major health problems.
nancies,” she says. impossible, but brain development stud- Whether a fetus will survive if delivered
ies provide some clues. The experience depends on a suite of other factors, Swartz
“Heartbeat laws” are misnamed of pain starts with the senses detecting says. They include fetal sex, weight, devel-
Texas law bans abortions “after detection something noxious. Those signals then opmental issues and mother’s health, not
of an unborn child’s heartbeat” at around have to travel to the cortex, the outer to mention individual health care facilities’
six weeks of pregnancy. But the rhythmic layer of the brain that helps interpret capabilities and training.
sounds heard on an ultrasound that early that sensation. In human fetuses, those The American College of Obstetricians
in pregnancy aren’t caused by the opening brain connections don’t exist until about and Gynecologists recently removed
and closing of heart valves as they move week 24 or 25 of pregnancy. In guidelines mentions of “viability” in guidance on
blood through the heart’s chambers, the written by members of the Society for abortion care. “It’s such a complicated
motion that produces a typical lubb-dupp Maternal-Fetal Medicine, researchers concept that we can’t make blanket
sound. Those chambers haven’t even note that these connections are neces- statements about it,” Verma says. “It’s
developed yet. On early ultrasounds, the sary for the experience of pain, but are something that needs to be left to the
heartbeat-like sounds are created by the not sufficient on their own to conclude clinician looking at the patient.”
ultrasound machine itself. that pain is possible. Inaccurate descriptions of biology can
“What we’re seeing is actually the prim- In human fetuses, these connections influence restrictions around reproduc-
itive heart tube and the cells in that heart aren’t operational until about week 28 or tive health, and as a result, the health
tube having electrical activity that causes 29 of pregnancy, other studies suggest. care people are able to receive, Swartz
fluttering,” Verma says. “The ultrasound is “We can say with really, really good con- says. A colleague, for instance, wasn’t able
actually manufacturing that sound based fidence that no sooner than 28 weeks is to get appropriate medical care when she
on the electrical activity and fluttering [pain] even possible,” Sandoval says. experienced signs of a pregnancy loss.
motion.” The vast majority of abortions — over Because of state abortion restrictions,
Using the term “heartbeat” to describe 90 percent — happen in the first trimester, her physician decided to delay treatment,
the fluttering makes sense in some situ- before week 13 of pregnancy. The number an emotionally distressing experience
ations, like in conversations with excited of abortions after 24 or 25 weeks is “van- that she wrote about in the September
parents-to-be, Verma says. “I’ve taken care ishingly small,” Swartz says. 2021 issue of Obstetrics & Gynecology.
of countless people who have seen that Abortion regulation based on flawed
first ‘heartbeat’ on ultrasound for a desired When a fetus could survive on medical and scientific premises, Swartz
pregnancy, and it’s this huge, exciting its own is a complex calculation says, “places priority on a potential life
WELL moment,” she says. “I don’t want to be dis- “Viability” is often used as a sharp cut- over the actual life of the person sitting
OT
E. missive of that.” She says two things can be off point to mark the age at which a in front of me.”
www.sciencenews.org | July 16, 2022 & July 30, 2022 7
NEWS
BODY & BRAIN Quebec study] got a mild disease. When
The latest on COVID-19 reinfections you get reinfected, you might [have
symptoms] like a cold, or even sometimes
A second round is rare, but repeat cases appear to be on the rise
a cough, and a little bit of a fever. But you
usually don’t progress to complications
BY MEGHAN ROSEN medRxiv.org. Quach-Thanh has seen a as much as you would with your first
Not long before the end of the school smaller rate in her own study of health infection — if you’re vaccinated.
year, my husband and I received an e-mail care workers first infected between March
from our fifth-grader’s principal. The sub- and September of 2020. Most of the people Does reinfection increase the
ject line included the words: “MULTIPLE in her study, which is unpublished, were chance of developing long COVID?
COVID CASES.” vaccinated. “A natural infection [and] three Durbin: That’s unknown, but it’s being
Several students in my daughter’s class doses of vaccines protects better than just studied. As we look back at the omicron
had tested positive for COVID-19. Her a natural infection,” she says. wave in the U.S. that happened in January
school acted fast. It reinstated a mask As many people gear up for sum- and February, now is about the time we
mandate for 10 days and required stu- mer plans, I wanted to know more about would start to see symptoms of long
dents who were not up-to-date on their COVID-19 risks. I talked with Quach-Thanh COVID. So far, we seem to be seeing a
COVID-19 vaccinations to quarantine. and Anna Durbin, an infectious diseases lower incidence of long COVID [after
These precautions may have helped; my physician at Johns Hopkins Bloomberg reinfection with omicron] than we did
daughter didn’t bring the virus home. But School of Public Health. Our conversations with primary infection. But those data are
for kids who do, COVID-19 can hopscotch have been edited for length and clarity. going to continue to be collected over the
through households, knocking down rela- next few months.
tives one by one. And it’s not clear how What’s the latest on reinfections?
long one infection protects against a Durbin: The strain circulating now is very How cautious do we need to be?
second round with the virus. Just a few different from the earlier strains. Whether Quach-Thanh: It depends on your baseline
months ago, scientists thought reinfec- you’ve been infected with COVID-19 or risk of complications. If you’re healthy, if
tions were relatively rare, occurring most vaccinated, your body makes an immune you’re doing most activities outdoors,
often in unvaccinated people. But there response to fight future infections. It rec- if you’re vaccinated, life can proceed. But
are signs the number may be ticking up. ognizes [the strain] your body originally if you’re immune suppressed or elderly,
Omicron, the variant of the virus that saw. But as the virus changes, as it did with the situation might be different.
sparked last winter’s surge, is still spawn- omicron, it becomes a fuzzier picture for If you have symptoms, it would be
ing sneaky subvariants. Some can evade the immune system. It doesn’t recognize advisable to not mingle in indoor settings
antibodies produced after infection with the virus as well. That’s why we’re see- without a mask. There are immunocom-
the original omicron strain, scientists ing reinfections. With respiratory viruses, promised people who might be at risk of
report June 17 in Nature. So a previous reinfections are very common. serious infection. We need to keep them
COVID-19 infection might not be as help- in mind. I think we have to be responsible,
ful against future infections as it once was. How can scientists distinguish a and if we’re sick, we should get tested.
Reinfection could even add to a person’s true reinfection from a relapse of
risk of hospitalization or other adverse an original infection? Durbin: This is what I tell my friends, fam-
outcomes, a preliminary study suggests. Quach-Thanh: There are multiple ways. ily and patients: This virus is here to stay.
Scientists are still working to pin down The first is looking at the time elapsed Any time you’re in a crowded place with
the rate of reinfection. Like most ques- between the first infection and a new poor ventilation and lots of people, there’s
tions involving COVID-19 case numbers, positive PCR test. If it has been more than a chance there’s going to be transmission.
the answer is more than a little murky. three months, it is unlikely to be just a The risk is never going to be zero. It’s a
“You really need to have a cohort of remnant of a previous infection. We can message people don’t want to hear. But
people who are well followed and tested also look at viral load. A really high viral as long as there are people to infect, this
every time they have symptoms,” says load usually means it’s a new infection. virus is not going away.
Caroline Quach-Thanh, an infectious dis- But the best way to tell is to sequence the We have to move to acceptance, and we
eases specialist at CHU Sainte-Justine, a virus [to determine its genetic makeup] to have to be better members of society. If we
maternal and pediatric hospital at the see if it is actually a new strain. can, we should stay home when we’re sick.
University of Montreal. If we can’t stay home, we should wear a
A look at hundreds of thousands of What do we know about mask. We should wash our hands regularly.
cases in Quebec found that about 4 percent the health risks of reinfection? These are things that reduce transmission.
were reinfections, scientists report in Quach-Thanh: The good thing is that most They reduce your risk of getting not just
a preliminary study posted May 3 at of the people who got reinfected [in the COVID-19, but also a cold or the flu.
8 SCIENCE NEWS | July 16, 2022 & July 30, 2022