Brain Over-Zoomed? Kill the Camera. And More Science News

Compiled by veteran medical journalist Brian Owens, this roundup of some of the newest science on the COVID-19 pandemic, straight from the scientific journals, is presented by Hakai Magazine in partnership with The Tyee.

Vaccine immunity wanes, but remains potent

While the COVID-19 vaccines remain effective, their potency has decreased in recent months, according to the U.S. Centers for Disease Control and Prevention. A study of more than 4,000 health-care workers between December 2020 and August 2021 estimated the vaccines were 80 per cent effective at preventing infection in fully vaccinated people, compared with 91 per cent in an earlier survey. The decline is likely due to naturally waning immunity and the rise of the Delta variant. The study looked at infections, and did not measure whether there was any change in the vaccines’ ability to prevent severe disease and death.

Morbidity and Mortality Weekly Report, Aug. 27, 2021

Turn off your camera to reduce Zoom fatigue

Everyone who has experienced a day of lengthy meetings on Zoom or other video conferencing applications is familiar with the feeling of being drained and exhausted by the end of it. Now researchers have found that your camera is likely to blame — it is more tiring to have your camera on during virtual meetings. The researchers say the “self-presentation pressure” associated with having the camera on — having a professional background and looking ready, or keeping children out of the room — is what leads to fatigue. They also found that these effects were stronger for women and for employees newer to the organization.

Journal of Applied Psychology, Aug. 30, 2021

One third of Americans were infected by the end of 2020

Approximately one third of the U.S. population had been infected with SARS-CoV-2 by the end of 2020, according to a new study using a computer model of confirmed and predicted infections. The analysis estimated that between March and December, 31 per cent of the population had been infected, while over the same period the infection fatality rate fell from 0.77 per cent to 0.31 per cent as diagnosis and treatment improved. But the researchers believe the fatality rate may actually be higher, as COVID-19 deaths were likely under-reported — and it is still higher than the 0.08 per cent fatality rate for seasonal influenza.

Nature, Aug. 26, 2021

Most hospital-acquired COVID-19 infections came from other patients

The majority of patients who caught COVID-19 while in hospital were infected by other patients rather than by health-care workers. A study at a hospital in the U.K. early in the pandemic found that out of 22 cases where patients were infected in the hospital 20 came from other patients, indicating that precautions taken to prevent staff from spreading the virus were largely effective. But the results were different for staff — those who were infected at work were just as likely to have gotten the virus from their co-workers as from a patient. The study also found that the majority of infections came from superspreaders — just 21 per cent of patients were the source of 80 per cent of the infections.

eLife, Aug. 24, 2021

Individualistic vaccine messages are most effective in the US

Messages that emphasize the individual rather than community health risks of COVID-19 seem to be more effective at increasing vaccine acceptance in the United States. A study conducted in July 2020, before vaccines were available, also found that messages that focused on the potential health problems from not getting a vaccine were more effective than those that stressed the benefits of getting one. The researchers now want to study how the misinformation circulating about vaccines might change how the messages are perceived.

Journal of Health Communication, Aug. 23, 2021

Symptomatic patients are more contagious

People with mild or moderate symptoms of COVID-19 are more likely to transmit the virus than those who do not show any symptoms. People who do get infected by someone who was asymptomatic are also more likely to be asymptomatic themselves. The study, which looked at around 9,000 close contacts of cases in China, also found that people are most infectious for the period two days before to three days after symptoms appear. The fact that the severity of symptoms is linked to the transmissibility of the virus indicates that while the vaccines may not stop transmission completely, they can significantly reduce it.

JAMA Internal Medicine, Aug. 23, 2021

Masking instruments can reduce transmission from musicians

While playing musical instruments can emit the same levels of potentially COVID-laden airborne particles as singing, simple safety measures, such as masking instruments, social distancing and implementing time limits, significantly reduce this risk. Bell covers over the end of an instrument significantly reduced the speed and amount of particles produced, while the amount of air that escapes from the keyholes of reed and woodwind instruments does not significantly contribute to any increased risk. Limiting playing time to 30 minutes indoors and 60 minutes outdoors, and leaving space between players also helped reduce the risk. But face shields and plexiglass barriers provided no extra protection.

ACS Environmental Au, Aug. 27, 2021