The Week - USA (2021-02-19)

20 NEWS Health & Science

A busy month for Mars
After a six-month, 300 million–mile journey,
the United Arab Emirates’ Hope spacecraft
entered orbit around Mars this week—the
first in a string of February visitors to the
Red Planet, reports Wired.com. The UAE’s
craft, which will study the Martian atmo-
sphere from 12,000 miles above the surface,
was joined hours later by China’s Tianwen-1.
That mission will attempt something previ-
ously achieved only by the U.S. and the
Soviet Union: a landing on the unwelcom-
ing Martian surface. After touching down,
China’s six-wheeled rover will spend three
months exploring Utopia Planitia, the
Red Planet’s largest impact crater. Finally,
NASA’s Perseverance rover is scheduled to
join the party on Feb. 18. If all goes accord-
ing to plan, a rocket-powered sky crane
will deposit the rover while hovering a few
dozen feet above the surface. Perseverance’s
primary mission is to collect samples that
can then be picked up by another spacecraft
later in the decade, hopefully providing
evidence that Mars once hosted microbial
life. Perseverance will also launch a small,
drone-like helicopter—the first attempt to
fly an aircraft on another planet.

One dose for Covid survivors?
People who have recovered from Covid-
may need only one shot of a two-dose vac-
cine to achieve a strong level of immunity,

a new study suggests. Researchers tracked

the immune response of 109 people who

had been given either the Pfizer-BioNTech

or Moderna vaccine. They found that the

41 people who had previously tested posi-

tive for Covid had an antibody response

10 to 20 times higher after the first jab

than those who had not had the disease. In

some cases, reports The Daily Telegraph

(U.K.), the response exceeded the degree

of protection provided by two doses. The

study also suggested that those who had

previously been infected were more likely to

suffer side effects from the first shot, such as

temporary fatigue or fever. While the study

hasn’t yet been peer reviewed, co-author

Florian Krammer, from the Icahn School of

Medicine in New York City, says one dose

“should be sufficient” for previously infected

people. This would spare people “unneces-

sary pain when getting the second dose, and

it would free up additional vaccine doses.”

A writing test for Alzheimer’s

Researchers at IBM think they can identify

the early signs of Alzheimer’s with a simple

writing test. The team examined a group of

80 people in their 80s who were part of a

long-running research project involving reg-

ular cognitive tests. Half of the participants

had Alzheimer’s; all had been cognitively

normal about eight years earlier. Using arti-

ficial intelligence, the researchers examined

responses to a simple cognitive test the

participants had taken before any devel-

oped the disease. Trained to look for subtle

differences in language, the AI identified a

group of people who were more repetitive,

made more spelling errors, and used simpler

grammatical structure. These people went

on to develop Alzheimer’s—overall, the AI

program predicted with 75 percent accu-

racy who would get the disease. Michael

Weiner, from the University of California,

San Francisco, tells The New York Times

this is “the first report I have seen that took

people who are completely normal and

predicted with some accuracy who would

have problems years later.” While there is

not yet a cure for Alzheimer’s, simple early-

diagnosis tests will be crucial if or when a

breakthrough arrives.

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An artist’s impression of Hope in orbit

In a potential breakthrough in the battle

against Covid-19, a new study has found

that vaccines might substantially slow the

transmission of the virus. Numerous vac-

cines have shown that they can massively

cut the number of people who experience

Covid symptoms or suffer serious illness or

die, reports The Washington Post. But less

is known about whether these shots also

stop asymptomatic infections that allow

the disease to keep spreading from one

person to another. For the new study—

which has yet to be peer reviewed—

researchers at Oxford University who

helped develop the AstraZeneca vaccine

collected nasal swabs every week from

some trial participants. They found a

67 percent reduction in positive tests after

the first dose of the AstraZeneca vaccine. If

the shots only made infections milder, the

researchers said, the positivity rate would

not have dropped. The study also found

that a single AstraZeneca dose was 76 per-

cent effective against symptomatic infec-

tions for at least three months. And the

vaccine’s efficacy increased when the full

two doses were given 12 or more weeks

apart rather than within six weeks, from

55 percent to 82 percent. That’s a boost for

the U.K.’s policy of delaying second doses

in order to get first shots in as many peo-

ple as possible—a strategy some scientists

say the U.S. should adopt. The AstraZeneca

vaccine is not expected to be authorized in

the U.S. before late March.

Vaccines may cut Covid transmission

Getting an AstraZeneca shot in the U.K.

Scientists have warned

that smoke from wildfires

carries countless variet-

ies of living microbes that

can find their way into our

lungs or cling to our skin

and clothing. Some of

these fungi and bacteria

may be harmful to the

firefighters tackling the

blaze—and to residents living downwind

from fires. Previous studies have found

that wildfire smoke accounts for as much

as half of all fine-particle air pollution in

the Western U.S. But while much is known

about the short-term effects of wildfire

smoke inhalation, little research has been

done on the longer-term impacts. “There

are many trillions of microbes in smoke

that haven’t really been

incorporated in an under-

standing of human health,”

co-author Leda Kobziar,

from the University of

Idaho, tells the Los Angeles

Times. “The diversity of

microbes that we’ve found

is really mind-bending.”

So far there is only anec-

dotal evidence of the microbes’ effect on

humans: Cases of Valley fever—caused by

inhaling spores of the soil-dwelling fungus

genus Coccidioides—spike every year in

Kern County, Calif., during wildfire season.

Kobziar says more research is needed to

determine the potential harm and risk.

What are they breathing in?

Microbe-laden wildfire smoke