The big point about the first dose of the Oxford/AstraZeneca vaccine is that it massively reduces the risk of serious disease and hospitalisations.
In the trials, no one given the vaccine was hospitalised. Which is why the government has decided to increase to three months the gap between the two doses.
It means that the 20m people regarded as the priority for vaccination, those aged over 50 or who are clinically vulnerable, can all receive at least one dose by the spring. It in effect doubles the pace of vaccination.
All that said, it is important to receive two doses, to obtain long term protection against Covid-19. Much more clinical detail will be provided shortly by the Medicines and Healthcare Products Regulatory Agency.
But as I said earlier, this is probably the most important decision by the government since the start of the pandemic, though tragically it comes too late to prevent hospitals being overwhelmed by the current viral surge.
At least, though, there is now well-founded hope for better times.