COVID booster: Nanobodies

Alpaca nanobodies block SARS-CoV-2 from entering cells

Researchers from the Walter and Eliza Hall Institute of Medical Research (WEHI) have identified neutralising antibodies that block SARS-CoV-2 from entering cells. These “nanobodies” are produced naturally by alpacas when immunised with SARS-CoV-2 spike proteins, the team shows in their paper, published in PNAS.

“The synthetic spike protein is not infectious and does not cause the alpacas to develop disease – but it allows the alpacas to develop nanobodies,” says Wai-Hong Tham from WEHI, lead author of the paper.

“We can then extract the gene sequences encoding the nanobodies and use this to produce millions of types of nanobodies in the laboratory, and then select the ones that best bind to the spike protein.”

The nanobodies were then combined into a “cocktail”.

“By combining the two leading nanobodies into this nanobody cocktail, we were able to test its effectiveness at blocking SARS-CoV-2 from entering cells and reducing viral loads in preclinical models,” she says.

Boarding planes back-to-front increases infection risk

Modelling shows that when boarding a plane back-to-front, people tend to cluster in aisles more, which can increase risk of COVID-19 transmission, according to a paper published in The Royal Society.

The idea for this research arose when US airlines attempted to mitigate the risk of infection by economy passengers passing already-seated business class passengers. However, the simulation showed that loading passengers with back seats first actually doubled infection exposure.

The authors suggest prohibiting the use of overhead baggage, which tends to make people stand in aisles for longer, and to board people who have window seats first.

Boarding plane simulations. Credit: Ashok Srinivasan.

How much do people understand informed consent about vaccine trials?

Consent forms for COVID-19 vaccine phase III clinical trials can be too long, difficult or complex to properly understand, suggests a paper published in JAMA.

The team systematically assessed consent documents from AstraZeneca, Johnson & Johnson, Moderna and Pfizer COVID-19 trials based on language, complexity, readability and later access of vaccines to the placebo group.

In all cases, they found that the documents required a language understanding above Grade 9 level and that they were too long and hard to read. The researchers suggest that shorter and more readable documents should be written in collaboration with an editor.

Text reminders may boost vaccination rates

A text-based nudge may get more people into vaccine appointments, suggests a paper published in PNAS.

The researchers sent 19 different types of texts to a group of more than 47,000 Americans. The text “Flu shot reserved for you” increased vaccination rates by 11%.

In their paper, the authors note: “Overall, interventions performed better when they were 1) framed as reminders to get flu shots that were already reserved for the patient and 2) congruent with the sort of communications patients expected to receive from their healthcare provider (i.e., not surprising, casual, or interactive).”

​They suggest this could inform wide-scale COVID-19 vaccination roll outs.

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