Few Biden actions wrt vaccines will have significant effect until May or June, simply because of the magnitude of what Trump and OWS set in motion.
By that time, we will likely have already reached herd immunity, or close to it. I saw a statistic saying that somewhere around 70% of people over 65 in America have received at least one of the two shots (so far, Johnson and Johnson, since they have only recently been approved, lags well behind the Pfizer and Moderna two-shots).