There’s little question that a COVID booster shot increases your immunity to COVID infection. Data out of Israel from the late summer and early fall leaves little question about that. The public debate – setting aside questions of global vaccine equity – has been about how long that increased protection lasts and whether it matters. Let’s take the second part first. The most important protection you get from COVID vaccination is protection against severe illness and death. A year’s worth of data shows that protection against bad outcomes remains robust even though protection against infection declines substantially after about 6 months. For healthy people under 65 is it worth another round of vaccination, especially if that top off of increased protection only lasts a few months?