Last checked at 
By Nancy Lapid
Feb 2 (Reuters) - The following is a summary of some recent
studies on COVID-19. They include research that warrants further
study to corroborate the findings and that has yet to be
certified by peer review.
Placenta may shed proteins to keep virus out
The placenta may have a way to protect itself and the fetus
from infection with the coronavirus, a small study suggests.
Researchers studied 24 women who gave birth between July
2020 and April 2021. Eight had symptomatic COVID-19 in the
second trimester, eight were sick from the virus in the third
trimester, and eight were not infected during pregnancy. When
COVID-19 occurred in pregnancy, particularly during the third
trimester, placenta cells appeared to "shed" a surface protein
called ACE2 that the virus uses to break into cells and infect
them, leaving fewer gateways for entry. Women who had COVID-19
in the third trimester had high levels of an enzyme called
ADAM17 that is known to help ACE2 release itself from the cell
surface, the researchers reported in The American Journal of
Pathology https://www.sciencedirect.com/science/article/pii/S0002944022000116.
The placenta may be sensing the maternal COVID-19 infection
"and possibly putting in place this mechanism to help shed off
ACE2, prevent SARS-CoV-2 from invading the placenta and passing
on to the fetus," said Elizabeth Taglauer of Boston Medical
Center. Earlier studies have shown that placental cells become
infected in only about 7% to 20% of pregnancies where the mother
has COVID-19, Taglauer said. When the virus does somehow get
into the placenta, it rarely reaches the fetus, she added. Her
team plans further studies of "protection pathways" that may be
keeping the virus out of placental cells and away from fetal
blood vessels.
COVID vaccines safe in rheumatic, musculoskeletal diseases
COVID-19 vaccines appear to be safe for people with
rheumatic and musculoskeletal diseases and are likely to trigger
flares - a sudden worsening of symptoms - in less than 5% of
cases, researchers have found.
The findings were based on data from 5,121 patients in 30
countries. Severe flares occurred in fewer than 1% of patients
after vaccination, they found. Overall, flares were more likely
to occur in patients with active disease, according to a report
published in Annals of the Rheumatic Diseases. "However, it is
important to note that flares can occur as part of the ...
disease, and the observed percentages of flare would be
compatible with the natural history of the disease rather than
necessarily caused by vaccines against SARS-CoV-2," said Dr.
Pedro Machado of University College London. The average study
participant was 72 years old, and most were women. Many had
inflammatory joint diseases, connective tissue diseases or
vasculitis and were receiving various combinations of
disease-modifying antirheumatic drugs, immunosuppressants, and
other medications.
Most had received the Pfizer/BioNTech
vaccine (70%), followed by shots from AstraZeneca (17%)
and Moderna (8%). "Our findings should provide
reassurance to rheumatologists, other health professionals and
vaccine recipients, and promote confidence in the safety of
COVID-19 vaccination in people with inflammatory rheumatic
diseases," Dr. Machado said.
Peer-review does not lead to major changes in "preprints"
Two studies published on Tuesday in PLoS Biology suggest
that papers posted on so-called preprint servers before
undergoing formal peer review do not change significantly before
publication in medical journals.
One study https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001285
compared more than 180 reports posted during the first four
months of the pandemic on the preprint servers medRxiv and
bioRxiv to the versions eventually published in peer-reviewed
journals. Roughly 83% of COVID-related papers and 93% of
non-COVID-related papers did not change from their preprint to
final published versions, they found. When the researchers did
identify changes, in the majority of cases those changes did not
qualitatively change the conclusions of the paper, they said.
The other study https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001470
used machine learning to analyze the relationships between
nearly 18,000 preprints on the bioRxiv server and their
published versions. Most manuscripts had only modest changes in
wording during the peer-review and publication process, the
researchers found.
Click for a Reuters graphic https://tmsnrt.rs/3c7R3Bl on
vaccines in development.
(Reporting by Nancy Lapid; Additional reporting by Marilynn
Larkin; Editing by Bill Berkrot)
