The UK has just approved the Oxford-AstraZeneca vaccine, according to BBC.com. This is expected to significantly increase the pace of the vaccination effort in the UK. To date, over 600,000 Britons have gotten the Pfizer vaccine. That should be about 0.9% of the population (my calculation).
The UK will now shift strategies and begin giving just the initial vaccination to at-risk people, in order to give as many as possible some degree of immunity. They will all ultimately receive the second dose, but that may happen after 12 weeks rather than after 3 or 4.