Andrew Marr suffered a “nasty bout” while Scotland player Billy Gilmour and the chief of defence staff Gen Sir Nick Carter have all joined the increasing numbers of those recently testing positive for Covid-19.
Such high-profile cases have served to highlight how infections are on the up as restrictions in England are poised to be lifted on 19 July. On Monday 22,868 cases were reported across the UK, the highest since late January, though only three deaths.
And, hand-in-hand with the positive test results are the many forced to isolate after coming into contact with those infected.
The question now facing scientists is how much of this uptick is due to lockdown fatigue and laxness over guidelines, the easing of restrictions, or the higher transmissibility of the Delta variant.
Johanna Konta, three-time grand slam semifinalist and the only British woman seeded in singles at Wimbledon, was forced to pull out of the tournament this weekend after coming in close contact with a team member who tested positive.
England footballers Mason Mount and Ben Chilwell had to isolate after contact with Chelsea teammate Gilmour in the tunnel after the England-Scotland game last week.
The Royal Ballet was also forced on Monday to cancel a string of performances in London “due to a number of dancers having to self-isolate”. Refunds will instead be issued for next month’s shows.
Meanwhile, after Carter tested positive, defence secretary Ben Wallace, the heads of the Royal Navy, RAF and Strategic Command were told to isolate after coming into “close contact” with him at a meeting, it has been reported.
BBC political interviewer Marr announced his news on Sunday, suggesting that he may have contracted the virus while covering the G7 summit in Cornwall this month. Despite being double-jabbed, the 61-year-old suffered symptoms similar to a “summer cold”, saying: “And very nasty it was too.”
Tim Spector, professor of genetic epidemiology at King’s College London, who runs the ZOE Covid study tracking the spread using self-reported data, said the increase in case numbers was due to “a combination of factors”. The “greater transmissibility” of the Delta variant, at the same time as “waning immunity after infection or vaccine”. The relaxation of social distancing was also a factor, he believed.
“Still most cases are in the under 30s,” he said, adding: “But one in four [is] now post-vaccine.” Another element, he said, was “ignorance over the new symptoms” when people were vaccinated.
Dr Elise Paul, one of the leaders of the UCL Covid-19 Social Study, said increased cases could be due to the high transmissibility of the Delta variant, and, possibly, a slight bending of the rules. The study’s most recent data had not shown “meaningful decreases in majority compliance with the rules”. But, she said: “We did see a small decrease in the proportion of people in our study reporting complete compliance (i.e. no bending of the rules of minor infringement)”.
Social psychologist Prof John Drury, of Sussex University, a participant in the Scientific Pandemic Insights Group on Behaviours (SPI-B) said the increase followed a relaxing of restrictions, and was “simply due to people following the rules but the rules being less strict”.
“But in addition there is a signalling effect when the government state that the rules will soon be dropped. We think this signals reduced risk and [it] leads people to be less careful about following the remaining rules.” The latest UCL survey found that since the easing of the restrictions compliance with most of the rules and guidelines “has remained high” however.
Prof Cath Noakes, specialist in airborne infections at Leeds University, who sits on the government’s Scientific Advisory Group for Emergencies (Sage), said it could be due to “people interacting more and possibly paying less attention as they do, particularly if they are vaccinated”. She added: “However it may simply reflect the rapidly growing number of cases in the UK – as the virus prevalence increases the probability of coming into contact with a case rises and we would expect to start to see more cases within all areas of the country and groups in society.”
Psychologist Prof Susan Michie, an expert adviser on SPI-B and to the World Health Organization (WHO), said: “Survey data show that people are travelling about and socialising more than previously – but this may be within guidelines.
“Current guidelines which allow mixing within indoor spaces for many hours, together with lack of mitigations such as ventilation in schools and other shared public spaces will inevitably mean increased transmission.
“This is especially so with the Delta variant which has been estimated to be 60% more transmissible than the previous variant, and in a population where a significant proportion are not double vaccinated.
“Even if people are double vaccinated, some will not have high immunity so will be susceptible to Covid-19.” WHO had stressed governments should not rely on vaccinations alone but continue with other protective behaviours such as masks and social distancing, she said.
The increase has raised questions over the super-transmissibility of the Delta variant, with reports in Australia it could potentially spread in social encounters of roughly five to 10 seconds, based on CCTV footage of people walking past each other in an indoor shopping area in Sydney in at least two instances. However, this is not considered the norm. There were no mask mandates in Sydney at the time, and less than 5% of the Australian population had been double-jabbed.