The question is how useful variant-specific boosters are at this point in time, though. As I understand it there are two things working against them. Firstly, o

The question is how useful variant-specific boosters are at this point in time, though. As I understand it there are two things working against them. Firstly, one of the main ways Delta seems to beat vaccination is by replicating more efficiency before the immune system can respond, and tailoring the vaccine more specifically to it won't really help with that. Secondly, a booster for a very similar variant might just boost the existing immune response for the previous variant rather than creating new, more specific antibodies ("original antigenic sin") - this is apparently one factor limiting the effectiveness of flu vaccines.