IT is nearly two weeks since Scotland moved to Beyond Zero and infections are rising rapidly again.
This was to be expected as physical distancing ended and larger groups were able to meet up again indoors, particularly in setting such as homes and pubs.
Nightclubs and the return of schools may be playing a part, although the uptick in cases clearly pre-dates both.
Between August 2 and August 17, the average number of new daily cases confirmed through testing rose by 75% from 1,115 per day to 1,952, although a separate report on wastewater surveillance indicates that levels were “rising substantially” by this point and “frequently doubling or tripling” at a number of sampling sites across Scotland.
Unsurprisingly, the main driver of the surge has been an increasing number of infections among people aged 15 to 24.
This group is much more likely than young children to experience symptoms and much more likely than adults to be unvaccinated, either through choice or ineligibility.
How much of a concern this is, in terms of NHS impact, and whether it will slow or accelerate remains to be seen.
As Professor Devi Sridhar, one of the Scottish Government’s Covid advisors and chair of global public health at Edinburgh University, noted this week: Scotland is “in new terrain” with “daily confirmed cases rising quickly within extremely high vaccine take-up” (more than 90% of adults and 34.5% of 16 to 17-year-olds have had at least one vaccine dose).
Right now, Covid medical admissions are falling.
The real strain for hospitals lies in an escalating demand for unscheduled non-Covid care – reflected in record admissions from A&E departments of people presenting with complex problems, undiagnosed cancers, or chronic conditions which have deteriorated over the past 17 months.
At the same time, beds have to be found for long-delayed elective surgeries, but a flurry of health boards (Lothian, Lanarkshire, Borders and Ayrshire and Arran) have paused planned operations in the past two weeks to accommodate emergency and urgent patients instead, with staff sickness, self-isolation, and annual leave also blamed.
Ongoing physical distancing requirements also limit capacity on wards.
With the school summer holiday over, students set to return to college and university campuses, and autumn approaching when people will tend to socialise more indoors, the probability is that infections will continue climbing rather than reverse.
If so, admissions to hospital will follow suit – albeit at a fraction of the rate they did last winter.
According to the latest Public Health Scotland report, you are three times more likely to be hospitalised with Covid if you are unvaccinated than fully vaccinated, at a rate of 12 admissions per 100,000 compared to four per 100,000.
But breakthrough infections happen, and they become increasingly common the higher the prevalence of the virus is in the community.
Between July 17 and August 13, there were 565 Covid hospital admissions in Scotland in people who were fully vaccinated.
If rates of influenza and other respiratory viruses (which are all currently at low or baseline levels for summer) spike, it wouldn’t take much for the NHS to lurch from pressure cooker to boiling point.
We might have been in a better position were it not for the Delta variant.
This was underlined this week by a major evaluation of the Pfizer and AstraZeneca vaccines’ efficacy against infections caused by Delta – the largest real-world analysis since it became dominant in May.
The headline message of the Oxford University study is that two doses of either vaccine remain your best protection – even if you have had a prior Covid infection.
But they are both less effective against Delta than they were against the Alpha (‘Kent’) strain.
For example, someone 14 or more days on from their second Pfizer dose is 84% less likely than an unvaccinated person to develop a symptomatic infection with Delta – down from 97% protection with Alpha.
And an unvaccinated person who has had a previous Covid infection is actually more protected naturally against Delta than someone fully vaccinated with AstraZeneca (by 71% vs 82%) – something that was not the case with Alpha.
That said, it is still worth someone with prior Covid getting vaccinated with AstraZeneca because this appears to boost immunity further, cutting their risk of infection by 88%.
The potentially more worrying discovery, however, was that where Delta infections did occur in fully vaccinated people, their “peak viral load” was similar to unvaccinated, infected individuals.
This was not the case with Alpha and signals that fully vaccinated people – should they become infected – may be more able to spread the virus on to others than they were earlier in the pandemic.
If so, this has implications for herd immunity (making it “likely unachievable”), quarantine policies, and for the viability of relying on vaccine passports alone – without an accompanying negative Covid test, for example – to make crowded indoor spaces safe.
The Oxford scientists say this “requires urgent investigation” but caution that the relationship between viral load and transmission risk is not necessarily straightforward.
For example, a greater percentage of the virus present in vaccinated individuals may be “non-viable”, or they may be infectious for a shorter period of time – something a recent study of hospitalised Delta patients suggested.
But once again, we are faced with evidence of just how much Delta has changed the equation for the worse.
The key conundrum for policymakers is what to do if cases do rise exponentially.
Would the public tolerate restrictions again, having had a taste of “freedom” – especially when the vaccines continue to provide very high protection against sever illness and death?
Might domestic passports, based on vaccination and Covid status combined, be a more palatable way of keeping venues open while still curbing spread?
Will booster jags help? – and if so, who gets them?
As always, there are no easy answers.