Thanks for this question. Please be aware that we are not able to provide legal advice on this forum. If you need to speak to lawyer about your specific situation, we have some suggestions on seeking legal help here: www.bihr.org.uk/help.
This issue has not yet been tested, so we don’t think there is a definitive answer! BIHR’s thoughts are that you cannot purchase (i.e., exercise your own commercial choice) on the vaccine at the moment as far as we are aware, it’s only via the NHS. This would indicate you wouldn’t necessarily have a choice. However, if there are health risks or protected belief risks associated with a particular vaccine in your case, these considerations would likely be covered by the right to be free from discrimination (protected by Article 14 of the Human Rights Act), and it would be objectively justifiable to provide an alternative. But the health/belief would need to be demonstrable.