When Boris Johnson unveiled his four-month roadmap out of lockdown in February, he said the vaccination programme was "creating a shield around the entire population, which means we are now travelling on a one-way road to freedom".
On Monday, he said the unlocking of our country and our lives was still on track as he used the Easter Bank Holiday news conference to confirm shops, pubs, gyms, hairdressers and restaurants in England will be able to reopen their doors once more from 12 April.
Self-catering holidays will be allowed, and people will again be able to travel around the country.
But as we tentatively emerge from this third lockdown after living under the cloud of the COVID pandemic for over a year, what "freedom" really looks like come 21 June when the lockdown lifting is due to be complete is a moving target.
The dates of the roadmap are set, but the contours of our destination are not.
When it comes to international travel, social distancing, COVID certification, mass testing and mass gatherings, the prime minister has commissioned plenty of reviews but he's not ready to give us any answers.
His reticence is in part political.
Dozens of his backbenchers are loudly mobilising a cross-party group to try to thwart his attempts to introduce COVID certifications.
And just as he doesn't want to show any ankle on the prospect of accelerating the roadmap, neither does he want to fan any political flames among colleagues on COVID certification at this stage of his unlocking plan.
But his reticence is also down to the tensions he is having to manage behind the scenes.
One senior figure tells me that there is a very live debate between Professor Chris Whitty, Sir Patrick Vallance and Boris Johnson on how to keep transmission low after we unlock.
His scientific advisers are minded to keep social distancing for another year, while the prime minister is not.
"He wants to get life back to normal," says one senior government figure. "So he's prepared to go for the certification and do it for livelihoods.
"If you allow pubs and restaurants to reopen at 40% capacity, they'll go bust anyway, so part of the debate behind closed doors is whether to drop social distancing in return for passports. That's part of the battle now."
Papers released by the Scientific Advisory Group for Emergencies (SAGE) on Monday stated that vaccines "aren't enough" to squash the coronavirus once and for all.
The modelling shows an increase in cases, hospitalisations and deaths as the unlocking continues and transmission from social mixing picks up pace.
For now, the prime minister faces deep political opposition to COVID certification, but might that change further along the route map when we start to reopen in earnest and the number of cases once again begin to spike?
When I asked him on Monday whether freedom beyond 21 June involves a COVID certificate and weekly testing, he told me I was "slightly putting the horse before the cart. We need to make sure we get stage two right".
Mr Johnson added: "If things continue to go well, I do think that, for many people in many ways, life will begin to get back to at least some semblance of normality."
What that "semblance of normality" looks like, the prime minister didn't want to expound upon on Monday.
But what's clear enough is that his "irreversible roadmap out of lockdown" will almost certainly come with a number of strings attached.
Vaccinations alone won't set us free.