Business A new trial shows that two vaccines combined are better defense against Delta and Omicron Published 3 years ago on 19 April 2022 By Terry Power Moderna is testing Omicron variant vaccine booster as trial Beta variant booster proves effective against original virus, Beta, Delta, and Omicron variants | Fortune You need to enable JavaScript to view this site. Related Topics:combinedDefenseDeltaOmicronShowsTrialvaccines