They're pretty ineffective from what I understand, but there are similar systems like the SEAram which is the same radar and targeting system but shoots missiles at the incoming missile. That is said to probably work against most hypersonic missiles.
Also it annoys me that people seem to think the US doesn't have hypersonic missiles. We developed the technology. We had a piloted mach 7 rocket plane in 1960. The X-15. We tested the Boeing X-51 Waverider in 2014, the fastest air-breathing aircraft of all time, it went mach 10 for 2 minutes, traveled like 700 miles. Obviously meant to be a hypersonic missile. I'd bet our SSGN submarines already carry hundreds of them.
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