The numbers are looking good for bringing this crisis to an end

The findings, said Matt Hancock, were “terrific”. And the Health Secretary had several reasons to be cheerful. For a start, the real world data to which he alluded showed that a single dose of Covid vaccine can slash transmission by up to half. Until now, scientific modelling on Britain’s route out of lockdown has been missing this crucial part of the jigsaw.

So the study from Public Health England, showing that even if vaccinated people are unlucky enough to get Covid, they are still far less likely to pass it on, was a major shot in the arm.

Speaking of which, Mr Hancock may also have been cheered by the news that the vaccine rollout was about to include him, along with other 42-yearolds. The good news didn’t stop there. Yesterday, the Office for National Statistics published new data showing that almost seven in 10 adults now have antibodies against Covid, in a leap towards herd immunity.

The sunny picture sharply contrasts with the modelling presented by the Government’s scientists less than a month ago, when Boris Johnson warned that normality was “still some way off ”, and promised to stick to his roadmap “like glue”.

Papers released by the Scientific Advisory Group for Emergencies (Sage) said that a full release from restrictions in June could trigger a wave of hospitalisations as bad as those in January. But the slew of new data adds weight to claims that many of their central assumptions were far too negative, or based on extremely partial information.

Key modelling from Imperial College London, drawn up last month, said that less than 45 per cent of the population would be protected against severe disease, due to vaccination or previous infection, by June 21. This, it said, was based on “optimistic” assumptions about vaccine efficacy, and on 2.7 million doses being administered weekly in England during the rollout.

In fact, the new ONS data shows that 68.3 per cent of adults already have antibodies to Covid, whether as a result of infection or vaccination. The figure has shot up from 51.5 per cent a month before, with the shift occurring as the pandemic waned, meaning the upswing can be largely credited to the

UK vaccine rollout. Nor did the modelling presented by Sage’s Scientific Pandemic Influenza Group on Modelling (Spi-m) factor in the possible impact of vaccines on onward transmission of the virus.

To that end, the latest PHE study, showing that just one dose cuts the risk of passing the virus to others in the same household by between 38 and 49 per cent, fills a critical gap. Scientists will now track the impact for those who have had both jabs – a category into which one in four adults now fall.

Yesterday the findings prompted growing optimism from scientists.

Dr Mike Tildesley, of Spi-m, said the new findings were “significant”, saying he was hopeful people would be able to hug their loved ones after June 21.

But there is far less optimism about whether the exit out of lockdown could be speeded up before then.

While ministers insist that “the vaccine is our way out” of this crisis, the NHS is battling with a very lumpy supply chain. The Prime Minister has repeatedly insisted the Government will meet its target – to offer all adults a first jab by the end of July.

But April has seen a major slowdown in the rollout of first doses, with an average of around 115,000 a day in the last week, as the programme moves through those in their 40s. At this rate,

The slew of new data adds weight to claims that many of Sage’s central assumptions were far too negative

While ministers insist that the vaccine is our way out of this crisis, the NHS is battling with a very lumpy supply chain

it would take six months for the programme to meet its targets. However, supplies are expected to be boosted in coming weeks, with thirtysomethings expected to start being offered jabs next month.

But the programme faces a difficult balancing act between now and the end of July, with around as many people requiring second doses as first.

Around 19 million adults are yet to have their first jabs – and around 20 million are due to get their second dose between now and the end of July.

Earlier this month, the decision was taken that those below the age of 30 should be offered an alternative to Astrazeneca, because of a possible link between the vaccine and blood clots.

Today, the Joint Committee on Vaccination and Immunisation will consider whether such a recommendation should be made for thirtysomethings. As a decision hangs in the balance, its deputy chairman Prof Anthony Harnden yesterday cautioned that any such restriction would delay the immunisation programme, and thus cost lives.

Meanwhile, ministers had some good news – a deal secured for 60 million more doses of Pfizer jabs. But these are not due until autumn, when they will provide a “booster” programme of third doses.