@SilverGlitterBaubles - the issue is that the mass vaccs centres and pharmacies don’t cover the whole country, so the government doesn’t want to tell everyone they can book - the invites are only going to people within a 45 min travel time. Which is obviously still millions of people. The letter also confirms that you are eligible, but obviously your date of birth does the same job, or most people who are CEV are very well aware of that as they’ll have been getting letters through the pandemic about shielding etc.
But it really is still absolutely fine for anyone over 70 or CEV to book - you’ve probably seen in the news the government is trying to get through as many in those groups as possible by mid Feb, so they really do want you to get jabbed in the next couple of weeks.