Washington -Moderna says its updated Covid-19 booster – mRNA-1273.222- generated significant number of antibodies against BA.4/BA.5 Omicron than its earlier shot. The study included about 511 people ages 19 to 89 who were vaccinated, then boosted with a 50-microgram booster dose of the bivalent booster, and showed higher neutralizing antibodies against the subvariants.