And the booster for Moderna is half the dose ... Now we recommend that these folks consider getting a fourth dose. The purpose of the fourth dose is the same for people who are not immunocompromised.

Now, what about the second booster, which, for people who received Pfizer and Moderna, would be their fourth shot? Who's eligible? Well, right now, you're eligible for a second COVID-19 booster if ...

The UK has become the first country in the world to authorise an updated COVID-19 booster vaccine directed at the Omicron variant, giving a green light to Moderna's mRNA-1273.214 shot.