By Nancy Lapid

(Reuters) – The following is a summary of some recent studies on COVID-19. They include research that deserves further study to corroborate the findings and that has not yet been certified by peer review.

Antibodies improve for months after mRNA vaccine

According to a new study, antibodies induced by COVID-19 mRNA vaccines continue to improve in quality for at least six months while the immune system continues to “train” its antibody-producing B cells.

After vaccination, some B cells become short-lived antibody-producing cells, while others join “germ centers” in the lymph nodes – essentially, a boot camp where they mature and hone 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 commit if the person is infected,” said Ali Ellebedy of Washington University in Saint Louis. Animal studies have suggested that so-called germinal center reactions last only a few weeks. But tests of the blood, lymph node tissue and bone marrow of volunteers who received the Pfizer/BioNTech vaccine showed that the germinal center reactions induced by the injections lasted for at least six months, with the antibodies increasingly becoming more effective in recognizing and attacking the spike protein of the original version. of SARS-CoV-2, Ellebedy’s team reported Tuesday in Nature https://www.nature.com/articles/s41586-022-04527-1.

They didn’t test the ability of the mature antibodies to neutralize the 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. Further research is needed to know if this robust germline center response is unique to mRNA vaccines or if it is also induced by more traditional vaccines.

COVID-damaged red blood cells cause blood vessel problems

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

Many patients hospitalized with COVID-19 are thought to have damage to endothelial cells lining blood vessels, which can lead to blood clots, organ damage and other complications. New findings in the blood of 17 moderately ill COVID-19 patients and 27 healthy volunteers confirm “deep and persistent endothelial dysfunction” as an effect of the coronavirus, researchers reported Wednesday in the Journal of the American College of Cardiology https:// /www. .jacc.org/doi/abs/10.1016/j.jacbts.2021.12.003. Compared to red blood cells in healthy people, those from COVID-19 patients release fewer beneficial nitric oxide molecules and more harmful inflammatory molecules, said Dr Ali Mahdi of Karolinska University Hospital in Stockholm. In combination with high levels of a certain enzyme, the inflammatory molecules damage the lining of blood vessels, his team found. As a result, the ship cannot relax properly.

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

Global project helps low-income countries reuse N95 masks

An international group of physicists, engineers, and physicians designed a cheap, easy-to-build cabinet with ultraviolet-C (UV-C) bulbs that enabled health clinics in low-income countries to decontaminate and reuse more than 900,000 N95 protective masks.

The prototype was built using a metal office storage cabinet covered in household aluminum foil, with UV-C bulbs on the front and back, members reported Wednesday. of the consortium in NEJM Catalyst https://catalyst.nejm.org/doi/full/10.1056/CAT.21.0439. “You simply load the masks onto a rack, put them in the cabinet, close the doors and turn on the device to apply the correct dose of UV-C to inactivate the COVID-19 virus,” said Dr Nicole Starr. , a surgical intern 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 optical company Optica to build the cabinets, sometimes working with embassies to arrange shipments of the necessary components. Teams of engineers from nine countries and hospitals from 12 countries worked on the project.

“A total of 21 cabinets were commissioned in hospitals, and we estimate 930,000 N95s were decontaminated for reuse from July 2020 through January 2022,” Starr said. Decontamination equipment currently used in US hospitals can cost $80,000 per unit, according to the report. The team estimated that their cabinet can be built for around $500 to $1,500 depending on location and can process nearly 5,000 masks per day at maximum capacity.

Click for a Reuters graphic https://tmsnrt.rs/3c7R3Bl on vaccines in development.

(Reporting by Nancy Lapid; Editing by Bill Berkrot)