New official data suggests a massive variation in the percentage of school staff who have had Covid-19 compared by local authority area.

The latest Office for National Statistics findings, from testing carried out in December, shows that the proportion of secondary staff with antibodies ranged from just 2.86 per cent in Reading to 27.95 per cent in Manchester.

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Tests from the earlier round one of the study - carried out in November - also revealed wide variation by local authority area.

Nationally, the December round two tests showed the average proportion with Covid antibodies, which indicate a past infection, was 15.7 per cent of secondary school staff and 14.6 per cent of primary staff.

The researchers behind the study said this showed that the teachers and other school staff participating had similar levels of antibodies as other working-age adults.

In total, 14.99 per cent of school staff tested positive for coronavirus antibodies in December, lower than the estimate of 18.22 per cent for working-age adults, according to a small study of schools.

The findings come a week before all pupils in England are set to return to class after months of remote learning.

School leaders and teachers have been left “disappointed” after government advisers decided against prioritising school staff in “crowded” classrooms in the next phase of the Covid-19 vaccine rollout.

But a leading Public Health England (PHE) expert said that the country is now in a “much better place” to reopen schools to children during the pandemic.

Dr Shamez Ladhani, a PHE consultant epidemiologist and the study’s chief investigator, said it was “extremely reassuring” that teachers do not appear to be at a higher risk of infection than working people of the same age.

In a briefing, Dr Ladhani said: “I think where we are now is in a really amazing place for reopening schools the right way.

“The country is still in lockdown, the infection rates are falling very, very rapidly, community infection and transmissions are going to be very low when they go back to school, and we’re not sending people back out into town because we want the kids to be safe.”

But he acknowledged that the Covid-19 reproduction number, or R value, may still increase when schools reopen.

Dr Ladhani said: “At the end of the day it’s very, very dependent on community infection rates as to what happens with schools.

“It’s not just about the schools. It’s about going to schools, it’s about parents actually using public transport to get their children to schools, it is about meeting and picking them up so the whole process of schooling comes with a small risk.

“It would be very naive to think that opening schools will not result in any changes in R rates or infection rates, but the bottom line is that the benefits of bringing children back to school far outweigh any risks that we see with Covid.”

The Schools Infection Study, from PHE, the ONS and the London School of Hygiene and Tropical Medicine (LSHTM), released on Monday, tested staff and pupils in 121 schools at least once over a few days in early December.

Overall, 12,203 school staff and pupils took part in the study on school sites between December 2 and 10.

Children and staff displaying symptoms would have been expected to be off school and self-isolating.

The study suggests that the proportion of participating staff and pupils who were positive for Covid-19 was lower than the surrounding community.

In secondary schools, 1.22 per cent of pupils and 1.64 per cent of staff overall tested positive for current infection, while in primary schools, 0.94 per cent of pupils and 0.99 per cent of staff tested positive for current infection.

But researchers said differences between primary and secondary schools were not statistically significant, and they stressed that the data collected in the study was not representative of all schools in England.

The data included 80 secondary and 41 primary schools in 15 local authorities.

Professor Sinead Langan, co-chief investigator of the study at LSHTM, said: “These findings show that some individuals attending schools have Covid-19 infections and therefore there is potential for transmission.

“However, it is still hard to say whether this infection is occurring within the schools or in the wider community.

“More investigation is needed to measure the tangible effect of school control measures implementations. The effect of the recently introduced twice-weekly home tests on infection prevalence within schools should also be carefully evaluated.”