Almost 70% of the adult population in England now have COVID antibodies, latest figures suggest.
An estimated seven in 10 adults (68.3%) in private households were likely to have tested positive for coronavirus antibodies in the week to 11 April, according to the Office for National Statistics (ONS).
The latest estimate is up from one in two, or 53.1%, two weeks earlier.
The presence of COVID-19 antibodies suggests someone has had the infection or has been vaccinated – and the inoculation rollout has now reached more than 33 million people across the UK.
In Wales, some six in 10 adults (61%) in private households tested positive for antibodies in the week to 11 April, according to the same new figures.
This is also up from around one in two adults, or 48.2%, two weeks before.
For Scotland, the latest estimate is six in 10 adults (57.8%) – up from just over four in 10 (43.8%).
And for Northern Ireland, the estimate is also six in 10 adults (62.5%) – up from just over one in two (54.6%).
Health Secretary Matt Hancock said: "Today’s ONS data shows more and more of us are benefiting from protection the vaccine gives us against this awful disease.
"The public’s response to the call to vaccines has been amazing, with over 95% of over 50s stepping forward.
"We can now see the impact in reality.
"The evidence is clear that the vaccine protects you, your loved ones and those around you.
"The vaccine is our way out and getting back to doing the things we have missed.
"This is a massive national effort – so when you get the call, get the jab."
On Tuesday, the UK recorded 2,685 new cases and 17 coronavirus-related deaths in the latest 24-hour period
Since the start of the pandemic, a total of 127,451 people have died in the UK within 28 days of testing positive for COVID-19, and there have been 4,409,631 lab-confirmed infections.
First doses of a coronavirus vaccine have now reached 33,843,580 after 90,695 people had their jab on Monday, meanwhile a quarter of adults are now fully vaccinated after another 304,688 second doses.
The next phase of the vaccine programme means those aged 42 and over in England are being offered the jab.
The encouraging antibodies survey come as domestic COVID-19 cases "look good" to enable foreign holidays from next month, according to Transport Secretary Grant Shapps.
The government is set to unveil plans for a traffic light system to allow overseas leisure trips to resume – but nobody will be jetting off for a holiday until 17 May at the earliest.
The traffic light system is expected to dictate where Britons will be able to go without self-isolating on their return, while some countries may require people to show proof of vaccination.
Speaking on Wednesday, Dr Mary Ramsay, head of immunisation at Public Health England, told MPs it is "very important" as many people as possible are vaccinated before all restrictions – including travel – are eased.
"It is really very important that we have as many people vaccinated before we release all those restrictions, so at the moment we are trying to balance it very carefully," she told the Science and Technology Committee.
She added: "There is a risk that we get a resurgence as we release restrictions – hopefully that will mainly lead to mild disease and younger people.
"But there will still be the risk that those people can potentially pass this on to older individuals who are, for whatever reason, either unable to respond to vaccine, unvaccinated or maybe if the vaccine begins to lose protection over time."