As far as I’ve read, no data on clinical effectiveness of the mRNA vaccines against the SA strain. There have been several reports where groups measure neutrali

As far as I’ve read, no data on clinical effectiveness of the mRNA vaccines against the SA strain. There have been several reports where groups measure neutralizing antibodies in serum of people who have received vaccines against the various variants (with some methodological differences between those reports). One recent preprint found a 100 fold drop off in neutralizing activity against the SA strain (https://www.medrxiv.org/content/10.1101/2021.02.14.21251704v1 https://www.medrxiv.org/content/10.1101/2021.02.14.21251704v...), but others have found a less steep drop off. Also, that’s just measuring neutralizing antibodies, not other cell-mediated components of the immune response, and it is not clear what dropoff in neutralizing antibodies is clinically meaningful. I think there is data on the reduction in hospitalizations and deaths with other vaccines against the SA strain, but I don’t have those refs on hand. I imagine clinical data on the mRNA vaccines and the SA and P1 strains is being gathered now.