Daily Sabah (Turkey)

Blood problems, antibodies induced by mRNA shots


IN THIS week’s roundup, the latest scientific research on the coronaviru­s and efforts to find treatments and vaccines suggest that antibodies improve for months after receiving an mRNA vaccine, red blood cells damaged by severe COVID-19 lead to blood vessel problems, and a global project may be the help that low-income countries are looking for as it supports reusing N95 masks.

Antibodies with mRNA

Antibodies induced by mRNA COVID-19 vaccines keep improving in quality for at least six months while the immune system continues to “train” its antibodypr­oducing B cells, according to a new study.

After vaccinatio­n, some B cells become short-lived antibody-producing cells, while others join “germinal centers” in lymph nodes – essentiall­y, a training camp where they mature and perfect their skills.

“Cells that successful­ly graduate (from germinal centers) can become long-lived antibody-producing cells that live in our bone marrow or ‘memory B cells’ that are ready to engage if the person gets infected,” explained Ali Ellebedy of Washington University in Saint Louis.

Animal studies have suggested that socalled germinal center reactions last only weeks.

However, analyses of blood, lymph node tissue and bone marrow from volunteers who received the Pfizer-BioNTech vaccine showed germinal center reactions induced by the shots lasted at least six months, with antibodies becoming increasing­ly better at recognizin­g and attacking the spike protein of the original version of SARS-CoV-2, Ellebedy’s team reported Tuesday in Nature.

They did not test the mature antibodies’ ability to neutralize variants, but in theory, Ellebedy said, the antibodies should be better able to recognize parts of the spike common to the variants and the original strain. More research is needed to know whether this robust germinal center response is unique to mRNA vaccines or if it is also induced by more traditiona­l vaccines.

Blood vessel problems

Dysfunctio­nal red blood cells contribute to the blood vessel injuries common in severe COVID-19, according to laboratory studies that also may suggest a way to treat the problem.

Many patients hospitaliz­ed for the coronaviru­s are thought to have damage to the endothelia­l cells lining the blood vessels, which can lead to blood clots, organ impairment and other complicati­ons.

New findings from the blood of 17 moderately ill COVID-19 patients and 27 healthy volunteers confirm “profound and persistent endothelia­l dysfunctio­n” as an effect of the coronaviru­s, researcher­s reported on Wednesday in JACC: Basic to Translatio­nal Science.

Compared to the red blood cells in healthy people, those from COVID-19 patients release fewer beneficial nitric oxide molecules and more detrimenta­l inflammati­on-causing molecules, said Dr. Ali Mahdi of Karolinska University Hospital in Stockholm.

In combinatio­n with elevated levels of a certain enzyme, the inflammato­ry molecules injure the blood vessel lining, his team found. As a result, the vessel cannot relax properly.

The dysfunctio­n is reversed by drugs that restore normal enzyme levels and limit production of the harmful molecules, Mahdi explained. Whether testtube findings can be replicated in people is not yet clear. The experiment was performed on the original coronaviru­s, so it is also unclear whether red blood cells are similarly affected in infections caused by variants of SARS-CoV-2.

Reusing N95 masks

An internatio­nal group of physicists, engineers and physicians has designed a cheap, easy-to-construct cabinet with ultraviole­t-C (UV-C) bulbs that has allowed health clinics in lower-income countries to decontamin­ate and reuse over 900,000 protective N95 masks.

The prototype was constructe­d using a metal office storage cabinet lined with household aluminum foil, with UV-C bulbs at the front and back, consortium members reported on Wednesday in NEJM Catalyst.

“You simply load the masks on a rack, put them in the cabinet, shut the doors and turn the device on to apply the right dose of UV-C to inactivate the COVID-19 virus,” said Dr. Nicole Starr, a surgery trainee at the University of California, San Francisco who led the effort.

The process takes about 10 minutes. Once the group had a workable design, they recruited members of local student chapters of the optics society Optica to build the cabinets, sometimes working with embassies to arrange for shipments of the necessary components. Engineerin­g teams in nine countries and hospitals in 12 countries worked on the project.

“Overall, 21 cabinets were put into use in hospitals, and we estimate that 930,000 N95s were decontamin­ated for reuse from July 2020 to January 2022,” Starr said. Decontamin­ation equipment currently used in United States hospitals can cost $80,000 per unit, according to the report.

The team estimated that their cabinet can be built for about $500 to $1,500 depending on location and can process nearly 5,000 masks per day at maximum capacity.

 ?? ?? A health care worker administer­s a dose of a Pfizer-BioNTech COVID-19 vaccine during a vaccinatio­n clinic at the Reading Area Community College in Reading, Pennsylvan­ia, U.S., Sept. 14, 2021.
A health care worker administer­s a dose of a Pfizer-BioNTech COVID-19 vaccine during a vaccinatio­n clinic at the Reading Area Community College in Reading, Pennsylvan­ia, U.S., Sept. 14, 2021.

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