Herd Immunity in April?
On 2/20/2021 4:37 AM, Dean Hoffman wrote:
The author is a professor at the John Hopkins School of Medicine.
https://www.wsj.com/articles/well-have-herd-immunity-by-april-11613669731
Brazil thought they had reached herd immunity. How's that working out
for them?
"Another surge was coming. This time, Uildéia Galvão thought they were
prepared.
Galvão, the lead physician in the coronavirus ward at a public hospital
in the Brazilian city of Manaus, had been haunted by the wave that
crashed last spring. In less than 10 days, it ruptured the citys
bewildered medical system. Sick patients were turned away. The dead were
piled into mass graves.
So Galvãos hospital organized contingency plans. Additional beds were
reserved, and a detailed schedule for opening them was created.
But the new surge, when it came, was different. The virus had mutated,
with a suite of alterations that probably made it more transmissible
and perhaps more lethal. Manaus was hit by what scientists call the P.1
variant. This time, it didnt take 10 days to overwhelm Galvãos
hospital. It took 24 hours.
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Even in a city as traumatized as Manaus, the horror has been unlike
anything doctors have seen. The oxygen quickly ran out. Dozens of
hospital patients have died of asphyxiation. Scores more, unable to get
care, have died at home. Every half-hour, one doctor said, a funeral
procession rumbled toward the cemetery.
We had a plan, Galvão said. We increased the availability of beds.
But even with that, there was strangulation.
The humanitarian disaster unfolding in the Amazons largest city has
shown what happens when government failures, scientific misfires and
public indifference meet a new, possibly more dangerous variant of the
virus that has ravaged the globe.
Believed to have been circulating in the Amazon since December, P.1 now
appears to be the dominant coronavirus strain in Manaus. Its been
detected in São Paulo and as far away as Japan. A first case was
identified in the United States on Monday.
Scientists are racing to understand the variant, one of several to have
emerged in recent months. They are trying to determine whether it truly
is more transmissible or has simply exploited lax behavior in a region
where many people are either unable or unwilling to take precautions
against the virus. The biggest unknown is whether the variant can infect
people who have recovered from the more common coronavirus strain.
A dying man, and a desperate search for an open bed
Doctors and front-line health workers are describing a dangerous new
chapter in the struggle against the virus. The shift came suddenly: It
wasnt just the surge in patients but the severity of their cases.
People started arriving at hospitals significantly sicker, lungs chewed
up with disease.
What has been said before, that this is a strain more transmissible but
not more severe thats not what is happening in Manaus,
epidemiologist Noaldo Lucena said. This isnt a feeling. Its a fact.
The global implications could be significant. Since the beginning of the
pandemic, Manaus, a city of 2 million swelling along the Amazon River,
has been closely studied by scientists. Local officials shied away from
lockdowns or restrictions that have been successful elsewhere. And what
policies did exist, many people ignored. The virus, believed to have
infected a large portion of the population, was left mostly free to
spread naturally.
Manaus represents a sentinel population, giving us a data-based
indication of what may happen if SARS-CoV-2 is allowed to spread largely
unmitigated, a team of researches wrote this month in Science.
For a time, after the wave of April and May subsided, scientists and
government officials wondered whether the city had achieved herd
immunity. Some scientists estimated three-fourths of the population had
been infected. Many believed the worst was behind the city.
Daily reported cases in Manaus through July
Why Manaus will be the first Brazilian city to defeat the Covid-19
pandemic, wrote a group of researchers from the Federal University of
Amazonas.
No one is saying that now.
A seductive vision unravels
In late December, as the holidays were set to begin, Amazonas state Gov.
Wilson Lima debated what to do. The daily counts of cases,
hospitalizations and deaths had begun to pick up. Scientists were
issuing increasingly urgent letters, calling on officials to institute
immediate restrictions on businesses and gatherings.
We need to save lives and not deepen the health an humanitarian
disaster, epidemiologist Jesem Orellana pleaded in one such missive.
Lives matter!
On Christmas Eve, Lima announced the closure of all nonessential
businesses. Protesters swept the city, closing roads and setting fires.
Business owners and lawmakers said the economy couldnt survive a
shutdown. A third of the citys workers are informal street vendors,
delivery men, maids. They pushed the governor to repeal the decree. And
within two days, he did.
The coronavirus has come roaring back into Brazil, shattering illusions
it wouldnt
Retailers and restaurants did brisk holiday business. Massive parties
some numbering more than 4,000 revelers gushed onto the streets. And
supporters of President Jair Bolsonaro, who has made inaction the
defining element of his pandemic presidency, rejoiced.
All power emanates from the people, tweeted Congressman Eduardo
Bolsonaro, the presidents son.
Regardless of the alarmist newscasts, Manaus has seen a large drop in
deaths since June, showing collective (or herd) immunity, tweeted Osmar
Terra, a former Bolsonaro cabinet member.
But that belief which seems to have seduced many in Manaus into a
false sense of security was quickly proved a fiction. Soon after the
holidays, deaths and hospitalizations exploded. The hospital system
buckled. The number of confirmed coronavirus deaths at home rose from a
total of 35 from May through December to 178 so far this month,
according to city health officials.
Daily reported cases in Manaus since October
That stunned Brazilian researchers who last month published a paper in
Science proclaiming that 76 percent of Manauss population had already
been infected with the virus.
How can you have 76 percent of people infected and, at the same time,
have an epidemic thats bigger than the first?" asked author Ester
Sabino. This was a concern from the moment cases started to rise.
To understand what was happening and why the city wasnt protected
from a debilitating second wave the team started sequencing fresh
samples, to see if any changes in the virus could explain it.
On Jan. 10, Japan announced the discovery of a new variant, found to
have infected four travelers from Brazils Amazon region. Then Sabinos
team published preliminary findings showing that the strain accounted
for 42 percent of the coronavirus cases sampled in December.
As viruses course through a population, they inevitably mutate, although
most such genetic changes are functionally insignificant. The
coronavirus has spawned countless variants around the world. But P.1
along with variants found in South Africa and Britain is provoking
particular concern.
Not only does it have a spike protein mutation that could lead to a
higher infection rate, it possesses whats called an escape mutation.
Also found in the South Africa variant, the mutation, known as E484k,
could help it evade coronavirus antibodies.
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Sylvain Aldighieri, a senior official with the Pan American Health
Organization who has been tracking the Manaus outbreak, said there is no
evidence to suggest that reinfections are driving the health crisis. We
would have many more reports, he said. We have to use our common sense
at this point. Herd immunity in Manaus was not achieved.
Other scientists have expressed doubt that 76 percent of people in
Manaus were infected.
Doctors said they havent seen many reinfections but cautioned that its
nearly impossible to know. The city was swept by the disease at a time
when shortages in supplies meant few could get tested. That early
failure has seeded todays: Without previous testing, its impossible to
confirm a reinfection.
One case, however, has been confirmed by scientists. Dozens more are
under analysis.
Mariana Leite, 31, an engineer in Manaus, said she tested positive for
antibodies in June and felt a sense of relief. She didnt think it
would be possible to be reinfected, but she said she was. Her polymerase
chain reaction test came back positive Jan. 8.
Its caused so much anxiety in everyone, she said. We feel like its
never going to end.
Meanwhile, the P.1 variant appears to have widened its reach: In
January, according to a sample of 48 cases, it represented 85 percent of
the infections.
The surge is like a horror film
The toll has been clear. By mid-January, the hospital system hadnt just
run out of beds, as it did during the first wave, but also oxygen. Wards
had been transformed, in the words of one epidemiologist, into chambers
of asphyxiation. Hundreds of patients were shipped out of the city,
some to the other side of the country.
The federal government was warned of the looming disaster, according to
an investigation requested by the supreme court, but didnt do enough to
avert it.
On Jan. 3, local health officials told federal officials the health
system would probably fail within 10 days. Then the company White
Martins, which supplies the public health system in Manaus with oxygen,
warned state and federal health officials it couldnt keep up with
demand. On Jan. 14 and 15, dozens of people suffocated to death.
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