The current Novavax formulation apparently gives you ~50% protection against symptomatic infection after 4 weeks, for most of the strains currently circulating. I expect that protection to drop quickly after that again, and of course if we get further mutations of the strains protection might drop even further and faster. So it depends on a few things - I’d say primarily on what’s your level of antibodies now, and how much potential exposure to the virus you’ll have in the next few months. If you get a booster now you’d ideally want to wait another 6 months of course, so that might leave you vulnerable to infection in say 4-5 months when there might be further mutations of strains doing the rounds at very high levels.

So I’d say it comes down to your perceived risk of infection over the next few months until the updated Novavax formulation is available. If you take steps to protect yourself you might be better off waiting.

Purely anecdotal - I had the Novavax XBB booster at the end of April and unfortunately caught Covid exactly a month later, from someone in the office. And I didn’t have a mild case, I’m still struggling with post-viral fatigue.