"Effectiveness of Primary and Booster COVID-19 mRNA Vaccination against Infection Caused by the SARS-CoV-2 Omicron Variant in People with a Prior SARS-CoV-2 Infection
Primary vaccination provided significant but limited protection against Omicron BA.1 infection among people with and without prior infection. While booster vaccination was associated with additional protection in people without prior infection, it was not associated with additional protection among people with prior infection."