#16,479
We seem to be in a bit of an informational limbo on COVID - at least from official sources - these past few days with relatively few updates coming from public health agencies. Hopefully that will change later today, as we expect updates from the CDC Nowcast and the WHO's mid-week update on COVID either today or tomorrow.
There are plenty of media reports, mainly containing speculation about where the pandemic will go after Omicron has run its course. No one really knows, but that isn't stopping the presses.
Journal articles, and preprints, are beginning to pick up again, following the holidays, including the follow pre-print - published yesterday on MedRxiv - that illustrates how antigenically different Omicron is to all of the other COVID variants we've seen to date.
I've included the abstract below, but you'll want to follow the link to read the report in its entirety - followed be a Twitter thread started by one of the authors; Professor of Applied Evolutionary Biology at Amsterdam University Medical Center, Colin Russell @colinrussell.
I'll have a postscript after the break.
Mapping the antigenic diversification of SARS-CoV-2
Karlijn van der Straten, Denise Guerra, Marit van Gils, Ilja Bontjer, Tom G Caniels, Hugo D van Willigen, E Wynberg, Meliawati Poniman, Judith A Burger, Joey H Bouhuijs, Ayesha Lavell, Brent Appelman, Jonne J Sikkens, Marije Bomers, Alvin X Han, Brooke E Nichols, Maria Prins, Harry Vennema, Chantal Reusken, Dirk Eggink, Menno de Jong, Godelieve J de Bree, Colin A Russell, Rogier Willem Sanders
doi: https://doi.org/10.1101/2022.01.03.21268582
Abstract
Large-scale vaccination campaigns have prevented countless SARS-CoV-2 infections, hospitalizations and deaths. However, the emergence of variants that escape from immunity challenges the effectiveness of current vaccines. Given this continuing evolution, an important question is when and how to update SARS-CoV-2 vaccines to antigenically match circulating variants, similar to seasonal influenza viruses where antigenic drift necessitates periodic vaccine updates.Here, we studied SARS-CoV-2 antigenic drift by assessing neutralizing activity against variants-of-concern (VOCs) of a unique set of sera from patients infected with a range of VOCs. Infections with ancestral or Alpha strains induced the broadest immunity, while individuals infected with other VOCs had more strain-specific responses. Omicron was substantially resistant to neutralization by sera elicited by all other variants. Antigenic cartography revealed that all VOCs preceding Omicron belong to one antigenic cluster, while Omicron forms a new antigenic cluster associated with immune escape and likely requiring vaccine updates to ensure vaccine effectiveness.
As much as I'd like to pop the champagne corks, and declare the pandemic to be near its end, SARS-CoV-2 continues to surprise us with both its tenacity, and its mutability.
While the COVID pandemic will eventually run its course, and Omicron might be its last hurrah, it is too soon to declare victory. No matter how badly we may want to.
