No virus variants can evade all antibody types, so far; new variants can
infect mice
Send a link to a friend
[March 20, 2021]
By Nancy Lapid
(Reuters) - The following is a roundup of
some of the latest scientific studies on the novel coronavirus and
efforts to find treatments and vaccines for COVID-19, the illness caused
by the virus.
No variants escape all types of antibodies, so far
The human immune system makes many antibodies in response to COVID-19
infection or vaccination, and no single variant of the new coronavirus
can yet escape all of them, according to a study posted on Thursday on
bioRxiv ahead of peer review. Researchers looked at how mutations in
coronavirus variants affect antibodies' ability to target a key region
on the virus spike called the receptor binding domain (RBD), which has
been mutating rapidly. In particular, the researchers studied three sets
of antibodies that were classified by the structural features that
affect their binding to the virus. Despite the diversity of antibodies,
just one class dominates the antibody response that targets the RBD,
they found. They also looked to see how many different classes of
antibodies can be evaded by new coronavirus variants. "Several lineages
have mutations that reduce binding by two of the antibody classes, but
so far no lineages have mutations that escape all three classes," said
coauthor Jesse Bloom of the Fred Hutchinson Cancer Research Center in
Seattle. "We suggest this is an important thing to keep an eye on as the
virus continues to evolve."
Coronavirus variants can infect mice
Some of the new coronavirus variants can cause COVID-19 in mice,
researchers have found. The implications, such as whether mice could
then transmit the virus to humans, will require further study, they
said. The original virus strain identified in Wuhan, China, could not
produce illness in mice because the spikes on its surface could not bind
well to the ACE2 receptor protein on the animals' cells. Some of the new
concerning variants - particularly the ones first identified in South
Africa and Brazil - have mutations that overcome this challenge, giving
them the ability to infect and sicken the mice, researchers reported on
Thursday on bioRxiv ahead of peer review. "This is indeed great news for
animal studies to better understand the infection and disease as mice
are widely available ... to study many pathologies, and easier to work
with than larger animals such as hamster or ferret," said coauthor
Etienne Simon-Loriere of Institut Pasteur in Paris. Whether mice can
transmit the virus to each other or to humans remains to be determined.
"We do not have expertise to evaluate the health risk posed by this
newly acquired capacity of SARS-CoV-2, but this is definitely something
that will need to be done," Simon-Loriere said. "No one wants the virus
to move to a new reservoir from where it could come back to humans, as
was feared with mink farms, and hopefully it will not happen."
[to top of second column]
|
The ultrastructural morphology exhibited by the 2019 Novel
Coronavirus (2019-nCoV), which was identified as the cause of an
outbreak of respiratory illness first detected in Wuhan, China, is
seen in an illustration released by the Centers for Disease Control
and Prevention (CDC) in Atlanta, Georgia, U.S. January 29, 2020.
Alissa Eckert, MS; Dan Higgins, MAM/CDC/Handout via REUTERS.
Homeless patients in Boston benefit from recuperation unit
Homeless people needed to be hospitalized for COVID-19 less often
after Boston Medical Center created a recuperation unit for them,
according to a new report. Boston experienced a surge in cases
during the spring of 2020, which disproportionately affected people
experiencing homelessness and threatened to overwhelm hospital
capacity. As a response, the COVID-19 Recuperation Unit was set up
near Boston Medical Center to provide isolation and quarantine space
for homeless people who didn't need hospitalization and were
medically stable, saving hospital beds for patients with severe
COVID-19. By the time the unit had been open for two months, the
hospital saw a 28% reduction in admissions of COVID-19 patients
experiencing homelessness, researchers reported in JAMA Network
Open. COVID-19 social distancing and quarantining restrictions "were
developed from the perspective of the 'haves' and not from the
'have-nots,'" said coauthor Dr. Joshua Barocas of Boston University
School of Medicine. "By re-centering the conversation on people
experiencing homelessness, we can actually see that resources are
needed in order to keep them and all of us safer."
(Reporting by Nancy Lapid; Additional reporting by Carolyn Crist in
Athens, Georgia; Editing by Bill Berkrot)
[© 2021 Thomson Reuters. All rights
reserved.] Copyright 2021 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
Thompson Reuters is solely responsible for this content.
|