Could someone help me understand the meaning of "to" in "to the dominant variants to increase their protection"? The complete paragraph is "It suggests that the UK needs to continue vaccinating vulnerable age groups 'at regular periods with updated vaccines' to the dominant variants to increase their protection." Shouldn't it be "for" instead of "to" in this context? Thank you!
As you say, vaccines for would be better than vaccines to. Vaccines against would be even better.
Or the whole paragraph could be rewritten:
It suggests that in order to increase their protection from the dominant variants, vulnerable age groups in the UK need to continue being vaccinated 'at regular periods with updated vaccines.'