A4 TUESDAY, JULY 28, 2020
Tracking an Outbreak
YOn the medical front, the world’s biggest coronavirus vaccine study
began on Monday. On the economic front, Senate Republicans called
for slashing the financial lifeline for Americans laid off in the pan-
demic. As part of a $1 trillion recovery package, they proposed a
$400-a-week reduction in an unemployment benefit that has soft-
ened the pain in millions of households and cushioned the economy
as the coronavirus has reached across the country.
States in the South and Midwest continued to struggle with
whether to shut down again to control the virus, which the Trump
administration has increasingly been forced to recognize as unre-
lenting. On Monday, the White House said that President Trump’s
national security adviser, Robert C. O’Brien, had tested positive for
the coronavirus. Although the White House said that neither the
president nor the vice president had been exposed, Mr. O’Brien
went to Florida with the president on July 10. He later went to Paris,
where he was photographed, shoulder to shoulder and maskless,
with four European officials.
On Monday, many state officials looked back at the weekend —
when photographs and videos from many bars and beaches showed
large crowds and few masks — and moved to enforce or impose
regulations. Kentucky ordered bars closed and restaurants re-
stricted to 25 percent of their capacity indoors. Gov. Andy Beshear, a
Democrat, took the action after showing a photograph of a crowd
scene and describing it as “people huddled together acting as if this
isn’t real and not following a single guideline.” He said that the trend
was “undeniable” and that the new rules were intended “to make
sure we don’t turn into Florida, Arizona or Texas.”
On Sunday, Dr. Deborah L. Birx, the Trump administration’s
coronavirus response coordinator, appeared with Mr. Beshear and
urged nearby states to take a hard look at closing their bars and
restricting public gatherings “to really make it possible to control
the pandemic before it gets worse.” She said that restrictions had
reduced the caseloads elsewhere. “Place like Arizona, where the
governor did close the bars, did put out a mask mandate for the ‘hot’
counties, did reduce indoor dining, did expand outdoor dining” had
seen “some plateauing and declining of new cases,” she said. Ari-
zona reported 1,813 new cases on Monday, 175 fewer than on Sunday
and roughly half the number posted on Friday.
Still, the mixed messages continued. The president, who went to
North Carolina to tour a biotechnology lab, said during a briefing, “I
really do believe a lot of the governors should be opening up states
that they’re not opening, and we’ll see what happens with them.”
Florida added just over 8,900 cases on Monday, bringing its total
to more than 432,000 — 16,000 more than New York’s and more than
twice as many as France’s. Oklahoma broke another state record for
single-day cases, with 1,244 cases.
Globally, the pandemic “continues to accelerate,” with a doubling
of cases in the last six weeks, said Dr. Tedros Adhanom Ghebreye-
sus, the director-general of the World Health Organization. He said
that of the six global health emergencies the agency had declared in
its 72-year history, the pandemic was “easily the most severe.”
He said the pandemic “has shown what humans are capable of,
both positively and negatively.” He said that “one of the most funda-
mental ingredients for stopping this virus” was “the willingness to
make hard choices to keep ourselves and each other safe.”
Fresh Outbreak in Vietnam
Vietnam yanked away the welcome mat in Danang, saying it
would evacuate tourists from that coastal city after more than a
dozen people tested positive for the coronavirus over the weekend.
Vietnam broke a streak of 100 days without a single local coro-
navirus transmission on Saturday when a 57-year-old man tested
positive. News agencies reported that 14 other cases had been con-
firmed since then. Officials said the strain of the virus found in
Danang was different from five strains detected there earlier.
The people being evacuated are mostly Vietnamese because the
country remains closed to foreign tourists. Vietnam had been widely
considered a success story. It sealed its borders early in the crisis,
called for widespread use of masks and began strict quarantine and
contact-tracing measures. There have been 420 cases and no deaths,
according to a New York Times database.
Several other places that seemed to have the virus under control
have sharpened their responses after sudden upticks in cases. Hong
Kong, which reported a record 145 new cases on Monday and has
had more than 100 new cases for six days in a row, imposed a re-
quirement for masks in public at all times. Officials also prohibited
dining in restaurants and limited public gatherings to two people.
Many Hong Kong residents maintain that the outbreaks can be
traced to people who were not covered by 14-day quarantine rule for
new arrivals, including airline pilots and business travelers. Some
residents say that such exemptions should be dropped, but the
government counters that they are necessary.
In Kenya, President Uhuru Kenyatta extended a nationwide
curfew for 30 days and banned alcohol from restaurants after criti-
cizing “reckless” behavior. In Zambia, 15 lawmakers and 11 staff
members tested positive for the virus. One of the lawmakers was
Princess Kasune Zulu, 44, who was known for being the first Zambi-
an legislator to declare that she had H.I.V. “We relaxed our rules too
early in Zambia,” she wrote on Facebook, urging Zambians to wear
masks and avoid gatherings, including church services. “Covid-19 is
moving rapidly.” As of Sunday, Zambia’s ministry of health had
reported just under 4,500 cases and 139 deaths.
By JAMES BARRONCoronavirus Update
Coronavirus Update wraps up the day’s developments with infor-
mation from across the virus report.National Security Adviser Tests Positive
W.H.O.: Pandemic ‘Most Severe’ in History
Hong Kong Sets New High in Daily Cases
New Coronavirus Cases Announced Daily in U.S.
THE NEW YORK TIMESMarch 1 July 27
Note: Monday’s total is incomplete because some states report cases
after press time. Data is as of July 27, 2020, at 5 p.m. Eastern.
Sources: State and local health agencies; hospitals; C.D.C.
As of Monday evening, more than 4,290,100 people across every
state, plus Washington, D.C., and four U.S. territories, have tested
positive for the virus, according to a New York Times database.
New cases7-day
average60,30,Average daily cases per 100,000 people
in the past week16 Few or
no cases32 48Hot Spots in the United States
THE NEW YORK TIMESAs of Monday evening, more than 4,290, 100 people across every state,plus Washington, D.C., and four U.S. territories, have tested positive for the
coronavirus, according to a New York Times database. More than 147,10 0 people with the virus have died in the United States.Nev.Ga.Miss.Conn.N.C.IowaN.D.Kan.Te x a sR.I.Mass.Ark.UtahMont.S.C.Mich.Calif.Wis.N.M.Ill.Fla.Wyo.N.Y.Ind.Minn.
Ore.MaineAlaskaTenn.Pa.Md.Ariz.Wash.N.H.HawaiiMo.Del.W. Va.N.J.IdahoD.C.OhioKy.Okla.La.Ala.Vt.Neb.S.D.Minn.Colo.
Va.Puerto RicoSources: State and local health agencies. The map shows the shareof population with a new reported case over the last week. Parts of a county with a
population density lower than 10 people per square mile are not shaded. Data for Rhode Island is shown at the state level because county level data is
infrequently reported. Data is as of July 27, 2020, at 5 p.m., Eastern.Researchers have long known
that masks can prevent people
from spreading airway germs to
others — findings that have driv-
en much of the conversation
around these crucial accessories
during the coronavirus pandemic.
But now, as cases continue to
rise across the country, experts
are pointing to an array of evi-
dence suggesting that masks also
protect the people wearing them,
lessening the severity of symp-
toms, or in some instances,
staving off infection entirely.
Different kinds of masks “block
virus to a different degree, but
they all block the virus from get-
ting in,” said Dr. Monica Gandhi,
an infectious disease physician at
the University of California, San
Francisco. If any virus particles
do breach these barriers, she said,
the disease might still be milder.
Dr. Gandhi and her colleagues
make this argument in a new pa-
per slated to be published in the
Journal of General Internal Medi-
cine. Drawing from animal experi-
ments and observations of vari-
ous events during the pandemic,
they contend that people wearing
face coverings will take in fewer
coronavirus particles, making it
easier for their immune systems
to bring any interlopers to heel.
Dr. Tsion Firew, an emergency
physician at Columbia University
who wasn’t involved in the work,
cautioned that the links between
masking and milder disease ha-
ven’t yet been proved as cause
and effect. Even so, the new paper
“reiterates what we say about
masks,” she said. “It’s not just a
selfless act.”
Ideas about the importance of
viral dose in the development of
disease have cropped up in the
medical literature since at least
the 1930s, when two researchers
formally noted that mice exposed
to larger quantities of germs were
more likely to die. More recently,
scientists have gone as far as to
puff different amounts of a flu vi-
rus up the noses of human volun-
teers. The more virus in this nasal
plume, they found, the likelier the
participants were to get infected
and experience symptoms.
That sort of experiment can’t be
done ethically for the new coro-
navirus, given how dangerous it
is. But earlier this year, a team of
researchers in China tried some-
thing similar in hamsters: They
housed coronavirus-infected and
healthy animals in adjoining
cages, some of which were sepa-
rated by buffers made of surgical
masks. Many of the healthy ham-
sters behind the partitions never
got infected. And the unlucky ani-
mals who did got less sick than
their “maskless” neighbors.
Some indirect data has been ac-
cumulating from people as well.
Researchers have tentatively esti-
mated that about 40 percent of co-
ronavirus infections do not
produce any symptoms. But when
some people wear masks, the pro-
portion of asymptomatic cases
seems to skyrocket, reportedly
surpassing 90 percent during one
outbreak at a seafood plant in Ore-
gon.
Wearing a face covering doesn’t
make people impervious to infec-tion, but these trends of asymp-
tomatic cases could suggest that
masks lead to milder disease, po-
tentially reducing hospitaliza-
tions and deaths.
Particularly compelling, Dr.
Gandhi said, is the data from
cruise ships, which pack big
groups of people into close quar-
ters. More than 80 percent of
those infected aboard Japan’s Dia-
mond Princess in February — be-
fore masking had become com-
mon practice — came down with
symptoms, she noted. But on an-
other vessel that left Argentina in
March, and on which all pas-
sengers were issued surgical
masks after someone onboard
came down with a fever, the level
of symptomatic cases was below
20 percent.
Some independent experts say
the paper is a welcome update,
given the pervasive idea that
wearing a mask is a mostly altru-
istic act.
“It’s been a real deficiency in
the messaging about masking to
say that it only protects the other,”
said Charles Haas, an envi-
ronmental engineer and expert in
risk assessment at Drexel Univer-
sity. “From the get go, that never
made sense scientifically.”
In other settings, too, from hos-
pitals to hair salons, face cover-ings may have driven down rates
of overall infection, perhaps pre-
venting disastrous outbreaks.
And countries like Japan, Taiwan
and South Korea, where out-
breaks quickly sparked a wave of
widespread masking, managed to
rein in the number of coronavirus-
related hospitalizations and
deaths early on.
Even in the United States, the
slow upward tick in mask-wearing
has coincided with what appears
to be a more modest death rate,
compared to the surge that oc-
curred after the virus first made
landfall in North America. These
trends have also likely been influ-
enced by increased testing, a
downward shift in the average age
of people contracting the virus
and improvements in coronavirus
treatments. Still, masks probably
aren’t hurting things, Dr. Gandhi
said.
The idea that face coverings can
curb disease severity, although
not yet proven, “makes complete
sense,” said Linsey Marr, an ex-
pert in virus transmission at Vir-
ginia Tech. “It’s another good ar-
gument for wearing masks.”
Dr. Marr and other researchers
are still sussing out exactly how
much inbound or outbound virus
different types of masks block.
But based on a wealth of past evi-
dence and recent observations,
the amount that’s filtered out is
probably high — perhaps 50 per-
cent or more of the larger aerosols
being sent in both directions, Dr.
Marr said. Certain coverings, likeN95 respirators, will do better
than others, but even looser-fit-
ting cloths can waylay some viral
particles.
Still, some experts are not
ready to embrace all ideas about
two-way protection.
What’s outlined in Dr. Gandhi’s
paper “is still just a theory, and
needs more research,” said Nancy
Leung, an epidemiologist at the
University of Hong Kong. While
there’s good evidence that masks
reduce the spread of viruses
within a population, it’s much
harder to nail down how face cov-
erings influence symptoms, Dr.
Leung said, in part “because of the
difficulty in conducting those
studies.”
Dr. Gandhi acknowledged these
limitations. But with no end to the
pandemic in sight, the need for
masks is only growing, she said,
especially as researchers contin-
ue to document the virus’s ability
to spread silently.
To tame this pandemic, people
should act as if they’ve been in-
fected, “even if you feel right as
rain,” Dr. Gandhi said.
Masks alone aren’t a substitute
for other public health measures
like physical distancing and good
hygiene. But unlike sustained
lockdowns that keep people apart,
shielding our faces is easier and
more sustainable, Dr. Gandhi said.
Safeguarding yourself and oth-
ers from this deadly disease, she
added, “is as simple as covering
up the two holes in your face that
shed the virus.”PREVENTING TRANSMISSIONWearing Masks ‘Not Just a Selfless Act,’ Experts Say
By KATHERINE J. WUExperts are pointing to an array of evidence suggesting that masks protect the people wearing
them, lessening the severity of Covid-19 symptoms, or in some instances, staving off infection.DUSTIN CHAMBERS FOR NEW YORK TIMESFANCIER FACE COVERINGS
With masks here to stay, con-
sumers are starting to demand
more than throwaways. Page B1.