AdvertisementStudies suggest sharp drop in vaccine protection vs. omicron — yet cause for optimismDecember 08, 2021Michaeleen DouclefffacebookEmailA man is vaccinated against COVID-19 at a clinic in Johannesburg, South Africa. The omicron variant appears to be driving a surge in South Africa. New studies suggest that vaccines might not be as effective against this variant but that a booster shot can be helpful. (Shiraaz Mohamed/AP)