This week's roundup of some of the latest scientific studies on the coronavirus and efforts to find treatments and vaccines for COVID-19 explores new tactics when it comes to vaccine dosing and sheds light on how the virus may damage body tissue without directly infecting it.

Coronavirus can damage the brain without infecting it

The new coronavirus does not need to directly invade brain tissue to damage it, a new study suggests.

Researchers examined the brains of 19 patients who died from COVID-19, focusing on tissues from regions thought to be highly susceptible to the virus: the olfactory bulb, which controls the sense of smell, and the brainstem, which controls breathing and heart rate.

In 14 patients, one or both of these regions contained damaged blood vessels – some clotted and some leaking. The areas with leakage were surrounded by inflammation from the body's immune response, they found. But the researchers saw no signs of the virus itself, a report in The New England Journal of Medicine said.

"We were completely surprised," said co-author Dr. Avindra Nath of the National Institute of Neurological Disorders and Stroke in a statement. The damage his team saw is usually associated with strokes and neuroinflammatory diseases, he said.

"So far, our results suggest that the damage ... may not have been caused by the SARS-CoV-2 virus directly infecting the brain," Nath said. "In the future, we plan to study how COVID-19 harms the brain's blood vessels and whether that produces some of the short- and long-term symptoms we see in patients."

Disinfecting during pandemic puts asthmatics at risk

Increased cleaning by people with asthma during the pandemic may be triggering flares of their disease, a new report suggests.

Researchers who surveyed 795 U.S. adults with asthma between May and September found the proportion who disinfected surfaces with bleach at least five times a week rose by 155% after the pandemic started. Use of disinfectant wipes, sprays and other liquids also increased, the researchers reported in the Journal of Allergy & Clinical Immunology: In Practice.

After accounting for other behaviors and risk factors, higher odds of having uncontrolled asthma were linked with greater household use of disinfectant wipes, disinfectant sprays, bleach and water solutions, and other disinfecting liquids. The study does not prove that increased frequency of disinfecting caused uncontrolled asthma. Still, the authors say, people with asthma need safer cleaning options.

The U.S. Centers for Disease Control and Prevention (CDC) advises asthmatics to ask someone else to clean and disinfect surfaces and to stay in another room when cleaners or disinfectants are used and right afterward. It also said soap and water may be sufficient for surfaces and objects that are seldom touched.

Researchers argue for one vaccine dose to enhance supply

A single dose of one of the currently available COVID-19 vaccines, even if less effective than two doses, may have greater population benefit, three research groups argued in three papers in Annals of Internal Medicine. In large trials, two-dose regimens of the vaccine from Pfizer Inc. and partner BioNTech SE and Moderna Inc.'s shot both demonstrated nearly 95% efficacy in preventing illness from the coronavirus.

Yale School of Public Health researchers say a less-effective single-dose might confer greater population benefit than a 95%-effective vaccine requiring two doses. University of Washington researchers say doubling vaccine coverage by giving a single dose to more people would hasten pandemic control by lowering transmission rates. Stanford University researchers say delaying second doses in some people could enable millions more to receive a vaccine.

"In a public health emergency, a powerful argument exists for doing something with less-than-perfect results if it can help more persons quickly," said Thomas Bollyky of the Council on Foreign Relations in an editorial published with the papers.

"However, whether alternative approaches with current vaccines would accomplish this goal is far from clear." The U.S Food and Drug Administration said on Monday the idea of changing the authorized dosing or schedules of COVID-19 vaccines was premature and not supported by available data.

Hair loss surges in NYC minority communities during pandemic

Pandemic stress may be causing people to lose their hair, according to a new study.

By mid-summer, rates of a hair-shedding condition called telogen effluvium (TE) had surged more than 400% in a racially diverse neighborhood in New York City, researchers reported in the Journal of the American Academy of Dermatology. From November 2019 through February 2020, the incidence of TE cases was 0.4%. By August, that rate had climbed to 2.3%, they found.

"It is unclear if the increase in cases of TE is more closely related to the physiological toll of infection or extreme emotional stress," said co-author Dr. Shoshana Marmon of Coney Island Hospital. The increase was due primarily to TE in persons of color, particularly in the Hispanic community, "in line with the disproportionately high mortality rate of this subset of the population due to COVID-19 in NYC," the authors said. TE rates rose in smaller nonwhite minorities as well, but not among blacks, who also were severely impacted by COVID-19.

Dr. Adam Friedman of George Washington School of Medicine and Health Sciences, who was not involved in the research, said he too is seeing increases in TE "and the timing makes plenty of sense, as the onset of shedding is typically three months following the traumatic event," which would correspond to the rise of the pandemic.