Today, January 29, reports from phase 3 trials of the single-shot Johnson & Johnson adenovirus vaccine, and of the two-shot Novavax protein vaccine were published, and both seem effective (both may be more effective than the two-shot AstraZeneca adenovirus vaccine). Nat probably got a dose of the Novavax two days ago.

Last night I watched the UCSF Virtual Grand Rounds, and Shane Crotty, an immunologist at the La Jolla Institute, presented a lot of background information on the potentially dangerous new virus variants in the UK, South Africa, and Brazil. He was guardedly optimistic that the current formulations of most of the vaccines, together with the resiliency of the human immune response (memory B cells, CD4⁺ T cells, and CD8⁺ T cells, as well as the wide variety of antibodies that arise from exposures) will still work with fairly good efficiency against these new variants. What stood out to me from his presentation was that the physical binding properties of the spike protein in the virus to the ACE2 and other receptors in the body, are not perfect predictors of which virus variants will prove more transmissible, more infectious, or more deadly. Predictions of which variant will predominate, how fast it will take over, and whether we will see the constant evolutionary emergence of more or less dangerous variants, is still a guessing game.

Crotty published a paper in Science: ‘Beyond sterilizing immunity, immune responses that confine SARS-CoV-2 to the URT and oral cavity would minimize COVID-19 disease severity to that of a ‘common cold’ or asymptomatic disease. This outcome is the primary goal of current COVID-19 vaccine clinical trials.’

By this fall, we will know a lot more.