Moderna says its COVID-19 shot 93% effective six months after second dose

Moderna Inc said on Thursday its COVID-19 shot was about 93% effective through six months after the second dose, showing hardly any change from the 94% efficacy reported in its original clinical trial. However, it said it still expects booster shots to be necessary ahead of the winter season as antibody levels are expected to wane. It and rival Pfizer Inc and BioNTech SE have been advocating a third shot to maintain a high level of protection against COVID-19.