If it is a subvariant, it is my understanding that the current vaccines are likely to be at least partially ineffective. That however is no excuse to rush out a vaccine for this subvariant. Those at high risk will need to decide if they believe the current vaccines will offer enough of the protection they want or if other methods to avoid the virus or minimize its impact is a better choice.
High risk of what? Covid vaccines do not prevent transmission. They do not prevent acquisition. They do not lessen the severity of infection. If you are at “high risk” of catching covid, it doesn’t matter how many vaccines you get you will still get covid. High risk low risk no risk is all the same outcome. Either you get covid or you don’t. It’s your immune system that determines how you react physiologically. Even though covid vaccines are supposed to teach your immune system how to react the infection still gets to the lungs and multiplies well before any immune response can occur.