Antibodies weak vs Omicron; treatment may help patients on ventilators

[December 18, 2021]  By Nancy Lapid

(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.

More evidence points to antibody weakness vs Omicron

Evidence emerging from lab experiments reveals weaknesses of vaccines and antibody drugs against the Omicron variant of the coronavirus.

In a study reported Wednesday on bioRxiv ahead of peer review, researchers at Columbia University found Omicron "to be markedly resistant to neutralization" by antibodies in blood from recipients of vaccines from Pfizer/BioNTech, Moderna, Johnson & Johnson or Oxford/AstraZeneca or from survivors of COVID-19. Next, they tested nine monoclonal antibodies that have been authorized for use and 10 that are still experimental. Neutralizing abilities of 18 of the 19 antibodies "were either abolished or impaired," including ones already authorized for use, they said.

European researchers reported similar results in a separate paper, also posted on Wednesday on bioRxiv. "Omicron was totally or partially resistant to neutralization" by the nine monoclonal antibodies they tested and by antibodies in blood samples from 90 vaccine recipients and COVID-19 survivors.

Both teams also found that even in vaccine recipients who received a booster dose, and in survivors who received vaccines, antibodies had substantially diminished neutralizing power. In these individuals, the European group said, neutralizing antibody levels were 5 to 31 times lower against Omicron than against Delta.

More frequent treatment may help COVID-19 patients on ventilators

A new study considers why COVID-19 patients on mechanical ventilators have trouble breathing and how refining a common treatment could help save lives.

A COVID-19 patient connected to a ventilator tube in the Intensive Care Unit (ICU) at the Centre Cardiologique du Nord private hospital in Saint-Denis, near Paris, amid the coronavirus disease pandemic in France, May 4, 2021. REUTERS/Benoit Tessier

A thin layer of fluid called pulmonary surfactant lines the air sacs in the lungs, helping to keep the sacs from collapsing at the end of each exhalation. Surfactant was first found to be important in premature babies, who are born without enough surfactant.

The study, published this month in the American Journal of Respiratory and Critical Care Medicine, shows for the first time that COVID-19 patients on ventilators have less surfactant in their lungs than healthy people.

When researchers treated 10 adult patients with the same artificial surfactant used in preterm babies, the benefit of treatment wore off very quickly and patients needed repeat doses far more often than expected.

The virus that causes COVID-19 infects and kills the lung cells that produce surfactant, but these cells will recover in time once the infection is over, the researchers said. The new findings suggest that in the meantime, "multiple surfactant doses over a number of days will be required ... until the lungs start to make their own surfactant."

(Reporting by Nancy Lapid and Christine Soares; Editing by Howard Goller)

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