THE “horrid” Delta variant of Covid-19 could push back plans to ease lockdown in Scotland by weeks, Professor Jason Leitch has warned.

Scotland’s national clinical director said the new strain has “changed the game” for the vaccine roll-out because of the lack of protection offered by the first dose alone.

He stressed the need to get both vaccinations to offer “decent” protection and suggested eight to 10 weeks of progress thanks to the vaccine had been “lost” because of the variant, which was first identified in India.

It came as Boris Johnson last night announced a delay to the end of England’s coronavirus restrictions by up to four weeks, after being warned the move could lead to thousands of deaths and unbearable pressure on the NHS.

Nicola Sturgeon is expected to lead a Covid-19 briefing this afternoon.

READ MORE: Boris Johnson announces four-week delay to England's Covid lockdown lifting

Speaking earlier on the BBC’s Good Morning Scotland, Leitch explained a four-week delay for first doses could allow nine million second doses across the UK, but said the Government was “trying desperately” to not impact the roll-out for younger people. Leitch commented: “The Delta variant has changed the game in one crucial way. Everything still works – distancing, ventilation, handwashing all still work – but what’s new about the Delta variant, and this is horrid, and we’ve learned it increasingly over the last few weeks, is the second dose is required for decent protection.

“You get about 30% protection from one dose, you get 80 to 85% from two. So therefore, if you’re thinking of this as a timeline, we’ve lost about eight to 10 weeks on that journey. We vaccinated about half the country’s adults twice, now we need to get that up.”

He urged any eligible Scots waiting for their second dose to consider the “open access” vaccine clinics. Leitch continued: “We’re desperate to get those vaccines in just as quick as we can, and that will allow us to give advice to the First Minister that says ‘yes, the game has now changed; the vaccine is changing and we can begin to relax a little bit more’.”

New data suggests the Delta variant is associated with about double the risk of hospital admission compared with the Kent variant. Researchers found that two vaccine doses still provided strong protection against the variant, which is now dominant in the UK. However, the level of protection may be at a lower level compared with the Alpha variant first detected in Kent, early research suggests.

Based on data analysed from 5.4 million people in Scotland, the Delta variant is now the dominant form of Covid-19 in the country. For the study period between April 1 and June 6 this year, there were 19,543 community cases and 377 admissions to hospital where a specific variant of Covid-19 was confirmed.

Of these totals, 7723 cases and 134 hospital admissions were found to have the Delta variant, which is thought to be about 60% more transmissible than the previously dominant Alpha variant.

As with other variants, people with underlying conditions were more at risk of being admitted to hospital. While vaccines were found to reduce the risk of being admitted to hospital, strong protective effects against the Delta variant were not seen until at least 28 days after the first dose.

In community cases at least two weeks after the second dose, the Pfizer/BioNTech jag was found to provide 79% protection against infection from the Delta variant, compared with 92% against the Alpha variant.

The Oxford/AstraZeneca vaccine offered 60% protection against infection with the Delta variant compared with 73% for the Alpha variant.

Experts say this lower vaccine effect may reflect that it takes longer to develop immunity with the Oxford jag.

Scotland yesterday reported 761 new coronavirus cases in the 24 hours previous. The figures showed that a total of 247,541 people had tested positive for the virus since the start of the pandemic.

No new deaths were recorded in yesterday’s figures, meaning the death toll remained at 7681. The daily test positivity rate was 5.2%, up from 5% the previous day.

A total of 128 people were in hospital on Sunday with recently confirmed Covid-19, with 17 in intensive care. Some 3517,668 people had received the first dose of a Covid-19 vaccination and 2,446,834 had received their second dose.