The Prime Minister said the process of protecting people from coronavirus was already going "exceptionally fast" but blamed supply for the current limitations in the system.
"We will be going to 24/7 as soon as we can," he told MPs at Prime Minister's Questions, adding: "At the moment the limit is on supply, we have a huge network – 233 hospitals, 1,000 GP surgeries, 200 pharmacies and 50 mass vaccination centres and they are going... exceptionally fast."
Health Secretary Matt Hancock will set out further details "in due course", Mr Johnson said.
Labour leader Sir Keir Starmer said he understood that pilot 24-hour centres were not yet open to the public but there would be a "huge clamour".
Mr Hancock earlier questioned whether there would be demand for a round-the-clock vaccination operation.
He said the NHS was "absolutely up for doing that" but "most people want to get vaccinated in the daytime, and also most people who are doing the vaccinations want to give them in the daytime, but there may be circumstances in which that would help".
In our poll, conducted from January 11 to January 13, more than 70% of respondents said that they would happily take an appointment for the Covid-19 vaccine at an unsociable hour, such as 3am.
Slightly more than 13% said they didn't think it would be fair on staff, echoing Mr Hancock's views from earlier in the week.
Around 8% said that they themselves wouldn't be able to attend an early hours appointment - although this may not have represented disapproval with the plan to extend vaccination appointment hours. Those who cannot attend an appointment through the night, due to work or health, may find that more appointments mean that it's easier to access a daytime time slot.
To round out the poll, 4% said that they felt the rollout was moving fast enough and extra appointments weren't necessary, while 2% said they didn't know.