When Laura Kelly took the call to collect her five-year-old son Arthur from his south London primary school it was with a wearying sense of déjà vu — this was the fourth time since last September that Covid-19 had interrupted his first year of education.

Although only one child in his school “bubble” had tested positive for the virus, roughly 60 children were sent home last Tuesday to self-isolate under UK government rules designed to contain the sharp rise in cases of the Delta variant, first identified in India, among school-age children.

As she copes with home-schooling Arthur and looking after his two younger siblings, Kelly, a director at a “Big Four” professional services firm, finds herself asking whether the ratio of positive Covid cases to the number of children taken out of school is sustainable.

“My fear is that if children are going to be self-isolating for 10 days every time one of them gets it, this will continue forever — unless they change the rules,” she says from her home in West Norwood.

For now Kelly, who is on maternity leave, is able to deal with the disruption at short notice. But that will change in October when Kelly, whose husband is employed full-time by a charity, returns to working full-time herself.

“I recognise we’re financially fortunate, but teaching a five-year-old phonics with two others in the house, when all he wants is to be running around outside with his friends, is very challenging. The fear is that this will be unsustainable come my return to work and will have a detrimental effect on our family, my son’s education and my career.”

The Kelly family is just one among thousands. Figures from the Department for Education for the week to June 19 showed that while 214,000 children were off school in England self-isolating, only 9,000 pupils had a confirmed case of the disease.

With 80-90 per cent of over-50s in England now double vaccinated, according to Public Health England, a growing number of educators, parents and politicians question whether keeping so many children off school can be justified when the academic year starts in September.

Geoff Barton, general secretary of the Association of School and College Leaders, said a feeling was growing that attempts to control the virus could not involve dozens of healthy children missing school for every positive case.

“This is not sustainable. We have to do something differently,” he said. “Leaders are having to navigate how to explain to parents, yet again, ‘your child has been sent home…’, especially where children have exams coming up next year,” he said.

Line chart of proportion of pupils unable to attend school because of  Covid-19(%) showing surge in UK secondary school pupils out of school.

In Greater Manchester, where the infection rate is now 291.9 cases per 100,000 population — nearly three times the national average — the mayor Andy Burnham is among those arguing that the rules are “disproportionate” given vaccination rates.

Instead, he advocates a system based on testing close contacts of confirmed cases to narrow the circle of those being sent home.

“The vast majority of current cases are in younger people, often with no symptoms. The solution could be daily testing of the contacts of people who have tested positive, enabling pupils to stay in school,” he said.

In County Durham, in the North-East, where case rates are running at nearly twice the national average, and many schools have sent groups of children home, parents and headteachers said they were also looking for a better solution.

Jane Davis, head of Lanchester EP primary school in Durham, which sent three groups of 60 children home this week after reporting 15 cases among pupils and five among staff, said the system “has to change”, potentially by treating Covid cases more like chickenpox.

Under the rules, schools only need to send immediate close contacts of those who test positive into quarantine; but while this may limit self-isolations in secondary schools, in practice for primary school children who can’t observe social distancing, entire “bubbles” are sent home.

“We can’t start a third academic year with these issues. We can’t allow such large numbers of children to continually isolate,” Davis said. “Being with your friends as a little one is the biggest part of your life. When they’re being sent home it’s awful to see.”

Cases per 100,000 people, 7-day rolling average (by 5 year age band)

Lesley Hamill, a teacher at Lanchester whose two sons are also at home after Framwellgate, their nearby secondary school, closed, said the uncertainty was bad for children. It also put a huge strain on parents who had to arrange childcare.

“It’s the uncertainty. Will they get back before the end of term and the summer holidays? I really can’t see that the current situation can continue much longer because it’s so disruptive. It can’t continue into next year.”

And while some families, such as the Kellys in West Norwood, have the financial and family networks to help them cope with the disruption, for those on lower incomes, or shift workers and single parents, the effects can be devastating according to campaign groups.

“If your family food budget is going down to the last penny each week, then having children at home snacking all day can drive you over the edge. Self-isolation also means you might miss that free meal at a church group, which helps balance the books,” said Helen Barnard, deputy director of the Joseph Rowntree Foundation, a charity.

She added that it was particularly hard on shift workers because employers started to see them as unreliable if they had children perpetually at risk of being sent home. “It might be unspoken, but there are no guarantees that you’ll get shifts back,” Barnard added.

Mike Brewer, chief economist at the Resolution Foundation, a think-tank, added that the self-isolation requirements were deepening the divide between those who can and cannot work remotely, and those who do and do not get financial support when asked to quarantine.

The Department for Education has remained cautious, arguing in a statement that a twice-weekly testing regime in schools, increased testing in high-prevalence areas and online lessons for those that do have to self-isolate are mitigating the damage.

But with the guidance not expected to change for the remainder of this academic year, the focus is now on September, when schools in England go back. The government has said advice on protective measures and isolation for the next academic year will be issued “in due course”.

Politically, the government will also need to reckon with a divided parental population, with some parents much more cautious than others.

A survey by Parentkind, a charity working with schools and families, found that 70 per cent of parents strongly agreed children should not have to wear face masks in class, while 24 per cent strongly disagreed.

A similar pattern emerged for the continuation of twice-weekly testing, with nearly 59 per cent strongly opposed and 24 per cent strongly supportive. “Not many people are sitting on the fence,” said John Jolly, Parentkind’s chief executive.

Scientists say that the government broadly has three options to mitigate the effects on children and families: either allowing the virus to run its course as herd immunity is established by vaccinating adults; instituting a more narrowly focused testing regime; or vaccinating large numbers of pupils.

On testing, the education department is running a trial in 200 schools in England in which close contacts of an infected child have daily on-site lateral flow tests to allow them to keep attending classes in person.

Alasdair Munro, a clinical research fellow in paediatric infectious diseases at Southampton university, told the Financial Times that given the poor adherence to quarantine rules, rapid testing “could very plausibly be even more effective in preventing transmission” than self-isolation regulations.

Scientists are more sceptical about the utility of vaccines. Logistical bottlenecks, parental refusals and concerns over rare cases of heart inflammation among adolescents caused by the jabs mean that vaccines are unlikely to be the “silver bullet” in the near future, according to Russell Viner, a paediatrics professor at University College London and an adviser to the government’s Scientific Advisory Group for Emergencies committee.

Ultimately, Munro speculates, a “quicker route” out of continuing disruption to children’s education may be high levels of vaccine-acquired immunity in the adult population ending the need for self-isolation edicts altogether.

“We have to remember it’s not a benign thing to do to dismiss children from school en masse,” he said. “It is possible we’ll get to a point when a really high proportion of adults have been vaccinated where we may decide such stringent rules in schools are no longer necessary.”