COVID SCIENCE - Omicron linked to rise in croup in babies; TB vaccine improves immune response to coronavirus

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.

Omicron linked with croup in babies

The Omicron variant of the coronavirus is causing a dramatic rise in cases of croup, a dangerous respiratory condition usually seen in babies and toddlers, new data suggest.

Croup, which causes a distinctive barking-like cough and high-pitched sounds when patients inhale, happens when viruses cause swelling in the respiratory tract that makes it hard to breathe.

From the start of the pandemic until mid-January 2022, emergency physicians at Boston Children's Hospital treated 75 children with croup, all but one of whom had COVID infections.

Eighty percent of those cases occurred after Omicron began circulating in December 2021, they reported in Pediatrics.

Most of the children were treated with steroids and sent home, but some required hospitalization. Overall, the children required more medication doses compared to children with croup caused by other viruses, the doctors found.

"There was a very clear delineation from when Omicron became the dominant variant to when we started seeing a rise in the number of croup patients," study leader Dr. Ryan Brewster said in a statement.

While many viruses can cause croup, parents should be aware of the possibility that a child with croup has COVID-19 and consider having them and other family members tested, the researchers advised.

Tuberculosis vaccine improves immune response to coronavirus

New research sheds light on how a tuberculosis vaccine might help protect against COVID-19.

Early in the pandemic, studies began to suggest that people who received the so-called BCG vaccine as children had lower rates of SARS-CoV-2 infection.

Research in hamsters now shows that animals vaccinated with BCG had less pneumonia due to COVID-19 and lower levels of the coronavirus in their lungs.

Doctors at Johns Hopkins University in Baltimore found important differences in lung cells between animals infected with SARS-CoV-2 who did or did not get the BCG vaccine, they reported on Tuesday on bioRxiv ahead of peer review.

Upon infection with the coronavirus, for the BCG-treated animals, antibodies came to lung cells much faster, lung repair mechanisms got underway much more quickly, and tissue-damaging inflammation was blunted, said coauthor Dr. William Bishai.

Earlier this month, researchers in India reported on the effects of BCG in recipients of the COVID-19 vaccine from AstraZeneca AZN.L in a small study.

The 21 subjects who had received the TB vaccine showed significantly "more robust" antibody- and T-cell attacks against the coronavirus than the 13 people who had not, they reported on Research Square ahead of peer review.

Combining BCG vaccines with COVID-19 vaccines "may offer synergistic protection," the Johns Hopkins team said. Clinical trials testing BCG vaccines for protection against COVID-19 are underway.

Critically ill COVID patients slow to wake after ventilator

Compared to how quickly an average patient "wakes up" after being taken off a mechanical ventilator, critically ill COVID-19 patients often take much longer to regain consciousness, researchers have found.

They reviewed data on 795 patients hospitalized with severe COVID-19 at three medical centers during the first two surges of the pandemic. All were on mechanical ventilation for at least six days, during which they were comatose.

After removal from respiratory support, 72% eventually regained consciousness, but 25% of them needed at least 10 days to wake up, and 10% needed 23 days or more to recover.

Patients who had experienced the most episodes of oxygen deprivation took the longest to recover consciousness, the researchers reported in Annals of Neurology.

"Our findings suggest that for patients with severe COVID, the decision to withdraw life support shouldn't be based solely on prolonged periods of unconsciousness, as these patients may eventually recover," Dr. Jan Claassen of New York-Presbyterian/Columbia University Irving Medical Center said in statement.

"These findings provide us with more accurate information to guide families who are deciding whether to continue life-sustaining therapy in unconscious COVID-19 patients," Classen's colleague, Dr. Brian Edlow of the Massachusetts General Hospital, said in a statement.