I missed the October CDC meeting which resulted in a decision to recommend a 2nd dose of the Covid-19 vaccine for those 65 years and older and for the immunocompromised.
The Evidence to Recommendations (EtR) slides by Roper indicated Covid-19 circulates year round, peaking in late summer and winter.
The recommendation that those in the above-named populations should get 2 doses of Covid-19 vaccine spaced 6 months apart seems based on reasonable considerations.
It looks like the vaccine would be the same as the one previously recommended for this year.
