ChAdOx1 COVID vaccines express RBD open prefusion SARS-CoV-2 spikes on the cell surface

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proven to be an effective means of decreasing COVID-19 mortality, hospitalization rates, and transmission. One of the vaccines deployed worldwide is ChAdOx1 nCoV-19, which uses an adenovirus vector to drive the expression of the original SARS-CoV-2 spike on the surface of transduced cells. Using cryo-electron tomography and subtomogram averaging, we determined the native structures of the vaccine product expressed on cell surfaces in situ. We show that ChAdOx1-vectored vaccines expressing the Beta SARS-CoV-2 variant produce abundant native prefusion spikes predominantly in one-RBD-up conformation. Furthermore, the ChAdOx1-vectored HexaPro-stabilized spike yields higher cell surface expression, enhanced RBD exposure, and reduced shedding of S1 compared to the wild type. We demonstrate in situ structure determination as a powerful means for studying antigen design options in future vaccine development against emerging novel SARS-CoV-2 variants and broadly against other infectious viruses.

Contemporary use of social media by consultant colorectal surgeons

AIM

There is evidence of significant growth in the engagement of UK health-care professionals with 'open' social media platforms, such as Twitter and LinkedIn. Social media communication provides many opportunities and benefits for medical education and interaction with patients and colleagues. This study was undertaken to evaluate the uptake of public social media membership and the characteristics of use of such media channels amongst contemporary UK consultant colorectal surgeons.

METHOD

Colorectal surgeons were identified from the Association of Coloproctology of Great Britain and Ireland (ACPGBI) national registry of colorectal mortality outcomes and were cross-referenced with the General Medical Council (GMC) register. Individuals were identified by manual searching on a number of social media platforms. Matching accounts were then examined to confirm ownership and to evaluate key markers of use.

RESULTS

Six-hundred and eighteen individual consultant colorectal surgeons from 142 health authorities were studied (79.5% were ACPGBI members and 90.8% were male). Two-hundred and twenty-nine (37.1%) had LinkedIn profiles (37.7% male surgeons, 29.8% female surgeons; P = 0.2530). LinkedIn membership was significantly higher in ACPGBI members (P < 0.001) and in those with GMC registration before 1997 vs after this date (39% before 1997 vs 30% after 1997; P = 0.03). LinkedIn members had a mean of 62 connections (median = 22), and 19 (3.1%) surgeons had Twitter profiles with a mean of 82 (median = 16; range: 0-914) followers and their accounts were followed by a mean of 87 (median = 27; range: 0-642) persons.

CONCLUSION

UK consultant colorectal surgeons are less engaged with social media than reported studies from other health-care professional groups. Further education and appropriate guidance on usage may encourage uptake and confidence, particularly in younger consultants.