As the data from initial studies into how Omicron evades our immunity continue to flow in, it's becoming more and more likely that a third dose - or booster - is going to be essential.
Several more studies have been released, all showing large falls in immunity to the Omicron variant.
One thing that the studies imply though is that there are much higher antibody levels in people who have either been infected, or received a third dose.
So how much will third doses be needed to combat Omicron?
Also on today's show:
Quick Fire Friday! (booster edition)