The World Health Organization (WHO) said that when the Covid-19 vaccine booster shots are introduced, they should be evidence-based and targeted at high-risk populations and frontline healthcare workers. br br The Strategic Advisory Group of Experts (SAGE), which advises WHO, stated in a recently released interim statement that booster shots should be administered first to populations at highest risk, but that evidence proving the efficacy of booster shots in combating the Omicron variant is needed first. br br SAGE said the targeted use of booster vaccination is vital, especially when the Covid vaccine's protection is declining in high-risk populations.