-
The way I understand it, the two part vaccine gives you about 50% protection after the first dose. The second dose increases this to around 80%. I’m guessing the thinking is that it’s initially more effective to get twice as many people protected to 50% and play catch-up later with the second dose.
Let’s say you have 100,000 doses available in time x. You can either have an initial protection rate of 80% of 50,000 people = 40,000, or 50% of 100,000 = 50,000.
It’s probably way more complicated than that.
Jonny69-
The vaccine actually gives more like 90% after first dose. The 50% figure includes the protection after the first week before the body has built up the antibodies (which is about 10% protection). So really the second dose is about longevity rather than protection.
Additionally with the more traditional vaccines (like the Oxford one) there is lots of evidence that a later second dose significantly prolongs the protection. However there is no evidence of this with the Pfizer (but no evidence to the contrary either)
jb000
Anybody understand the change in dishing out the vaccine? The testing was done on 21 days between two doses, approval based on this and pharma say they didn't test other time frames, yet the govt are now going to go for 12 weeks between doses to increase the amount of people vacinated. Is this a massive gamble?