4th vaccine shot less effective against omicron, Israeli study finds; new Va. governor faces mask pushback: Live COVID updates USA TODAYFourth vaccine dose boosts antibodies, researchers say, but likely not enough to prevent Omicron breakthrough infections CNNIsraeli trial, world’s first, finds 4th dose ‘not good enough’ against Omicron The Times of IsraelIsraeli study shows 4th shot of COVID-19 vaccine less effective on Omicron Yahoo NewsWhat study says about efficacy of fourth Covid-19 vaccine shot CNNView Full Coverage on Google News