Adaptation of booster vaccines against omicron variants important for COVID-19, study shows

Booster vaccinations (third and fourth vaccinations) of COVID-19 mRNA vaccines that are not adapted to omicron variants do lead to higher blood levels of neutralizing antibodies against the omicron subvariants. However, these antibody titers drop significantly six months after the third or fourth vaccination. The fourth vaccination also had no effect on the breadth of the immune response against different virus variants.