Without wishing to be accused of scaremongering this has just gone up on the Guardian live feed:
"Covid-19 vaccines do not completely prevent transmission, Prof Anthony Harnden, deputy chair of the Joint Committee on Vaccination and Immunisation (JCVI) has said.
He told BBC Breakfast on Sunday that while they appear to reduce transmission by about 50%, vaccinated people can still get the virus and spread it to others.
He added:
There’s some good evidence now from Public Health England and from the Oxford/AstraZeneca trials that the vaccines do prevent transmission.But they don’t completely prevent transmission. The figures are still being calculated but it’s in the order of 50%.
So, there will be some reduction in transmission, no doubt at all, but it’s still possible, even though you’ve been vaccinated, to get infected, have no symptoms and transmit it to others. That’s why it’s important that all those who get vaccinated still stick to the rules."
I think this is pertinent to the discussion, and explains somewhat the current roadmap logic.
I'm hoping that a reduction of 50% in transmission is indeed enough to stop a third wave, but only time will tell.