Due to how irregular deliveries from AstraZeneca are, Canada is looking at giving people who had AZ for the first shot a different vaccine for the second shot. We are looking at UK and possibly other studies on this. The preferred course of action is to give people two doses of the same thing, but if that isn't possible then we will likely give them a dose of whatever else is available. We are using up doses as they arrive and have not been holding any back for second doses, at least not so far.Our region in Spain has stopped giving the AZ vaccine as a first dose. Nothing to do with blood clots or anything like that, just that AZ deliveries are haphazard, not guaranteed and have again failed to meet the promised amount for delivery.
They have 118,000 AZ vaccines left and will use them for those in the 60 to 69 age group who have received it as a first dose which is about 100,000. The promised 120,000 for this week was, once again, reduced to 12,000. There are still about 230,000 in that age group to be done so they'd need 460,000 to give both doses and that is proving impossible. They will now use the Pfizer vaccine, which is meeting its deliveries, so that they can ensure everyone gets both jabs in the recommended time frame of 3 weeks.
There have been news reports which have said there is reason to believe that two different shots may actually work better than two of the same thing, so this is not necessarily a second best option. The UK studies will be looked at very carefully in this regards.