Final answer:
Booster shots can enhance immunity against the Omicron variant, as shown in studies published in the New England Journal of Medicine and the Lancet.
Step-by-step explanation:
Several studies have been conducted to assess the efficacy of booster shots against the Omicron variant. One study published in the New England Journal of Medicine found that a booster dose of the Pfizer-BioNTech vaccine increased neutralizing antibody titers against Omicron by a factor of 25. Another study from the Lancet reported that two doses of the Pfizer-BioNTech vaccine provided limited protection against symptomatic Omicron infection, but a booster dose significantly boosted the immune response. These studies suggest that booster shots can enhance immunity against the Omicron variant.