THE pandemic has reached a precarious juncture with cases on the rise UK-wide but lingering uncertainty over how much further it is safe to progress back towards normality.

In England, Boris Johnson is under pressure from many of his own MPs and business supporters to press ahead with the June 21 'Freedom Day' plans which would see social distancing rules abandoned and nightclubs allowed to reopen. Many scientists are urging caution, however.

Scotland was originally on course for Level Zero nationwide from June 28, but with much of the Central Belt still at Level Two this is certain to be delayed.

READ MORE: Covid hospital admissions double in Scotland - but rise is slower than during second wave

The optimistic outlook is that while infections have been rising rapidly, it is not yet putting the same pressure on hospitals.

Roughly speaking, cases now are translating into half as many hospital and intensive care admissions as they were at a similar point in the second wave back in September.

This is what we would expect to see if vaccines are 'breaking the chain' between infection, serious illness, and death.

HeraldScotland: First and second dose vaccine coverage, by age group, in ScotlandFirst and second dose vaccine coverage, by age group, in Scotland

To date, 97 per cent of over-65s, who have accounted for 89% of the Covid deaths in Scotland, have been fully vaccinated.

Evidence indicates that - for the Delta variant which now accounts for three quarters of UK cases - the Pfizer vaccine provides 88% protection from symptomatic disease (cough, fever, aches etc) from two weeks after the second dose, with the AstraZeneca vaccine 60% effective. The risk of serious illness would be much lower - though never zero.

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Why then can we not just scrap all restrictions if the most vulnerable are immunised?

A major concern is that the new Delta variant appears to be much more transmissible - according to UK Health Secretary Matt Hancock 40% more transmissible than the Alpha (Kent) strain, but on more pessimistic scientific estimates anything from 30-100% more transmissible.

This has triggered alarm bells because modelling by SAGE in May forecast that a variant which was 40-50% more transmissible than the Alpha variant could still cause a surge in hospitalisations larger than the first or second waves without restrictions to mitigate its spread - and that was before considering whether the variant was less responsive to vaccines (evidence suggests a single vaccine offers 33% protection against infections caused by the Delta variant, compared to 50% for the Kent variant).

Then there is the risk from Long Covid, which remains an unpredictable game of Russian roulette even among the healthy and young. A study last week found that 376,000 people in the UK had been experiencing Long Covid symptoms, such as brain fog or debilitating fatigue, for at least a year after their initial infection.

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Further data from Public Health England last week also indicates that people infected with the Delta strain are more than twice as likely to end up in hospital compared to those infected with the Alpha strain, once adjusting for factors including age and vaccination status.

As epidemiologist Dr Deepti Gurdasani put it: "we could have quite damaging consequences if we let cases go out of control at this point in time".