COVID Booster: memory, eyes, and more vaccine data

Sputnik V might not work well against variants

In phase III trials, Russia’s adenovirus vaccine, Sputnik V, recorded an efficacy of over 90%, but it may not be as effective against COVID variants, according to research in Nature Communications.

The researchers took serum samples from 12 Argentinian volunteers, who had all been fully vaccinated with Sputnik. They found the blood could neutralise the Alpha variant of COVID, but wasn’t as effective against the Beta strain.

The researchers suggest that Sputnik is still probably good at preventing severe COVID-19, but it may not be as effective at stopping transmission.

COVID-19 affects the memory

A Norwegian study has found that people can have memory problems after testing positive to COVID-19.

The study, published in JAMA Network Open, surveyed nearly 13,000 people in Norway immediately after getting a COVID test, and then eight months after getting the test.

Roughly 11% of those who tested positive reported memory trouble, compared to 4% who tested negative.

Long COVID could be spotted in the eyes

A small study in the British Journal of Ophthalmology has found a couple of markers in the eye that could be a feature of long COVID.

The researchers examined corneal scans of 40 people who’d had a confirmed COVID infection, 22 of whom had some symptoms persisting for longer than a month. They compared these scans to those of 30 people who hadn’t had COVID.

The researchers found that subjects with long COVID had greater corneal nerve fibre damage and loss, with higher numbers of dendritic cells (immune cells), than those who were COVID negative.

The researchers suggest this could be a useful way to evaluate long COVID.

COVID-19 decreased lifespan by nine years in parts of North America

A study published in PLOS has examined the “mean unfulfilled lifespan” of COVID-19 in the US.

“As a few other demographers, I initially tried to convey the mortality impact of COVID-19 by assessing how much life expectancies would decline during the pandemic,” says Patrick Heuveline, a researcher at the University of California, Los Angeles, and author of the paper.

“When mortality conditions are continuously changing, however, life expectancies are hardly interpretable and I wanted to provide a more intuitive indicator of that mortality impact.”

The mean unfulfilled lifespan is the difference between the average age of people who died in a particular timeframe, and the average age the people would normally have lived – during a pandemic, when people are dying at unexpectedly high rates, there could be a difference of several years between the two.

In New Jersey and Mexico City, Heuveline estimates that the mean unfulfilled lifespan reached 8.91 and 8.96 years, respectively.

Spotting ‘breakthrough’ infections in the fully vaccinated

We know it’s possible – but a lot less likely – for people who are fully vaccinated to catch COVID-19, and an Israeli study has examined the antibodies of fully vaccinated healthcare workers who tested positive to COVID-19.

The researchers took blood samples from 1497 workers who’d received both doses of the Pfizer vaccine. Out of this group, 39 workers became infected with COVID-19 after vaccination. These people had lower levels of antibodies, according to the researchers.

The study is published in NEJM.

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