Antibody prevalence found to be highest among secondary school students in England

Over three quarters of secondary school pupils and nearly half of primary schools pupils are estimated to have had antibodies against COVID-19 in December last year, according to new data from the Schools Infection Survey (SIS).

Antibody prevalence was highest in secondary school students (82%), compared to 40% prevalence in primary schools. This difference could be due in part to secondary school students being eligible for the COVID-19 vaccine at the time of testing. Therefore secondary school students could have antibodies as a result of natural infection or vaccination, whereas the antibodies in primary school students reflects mostly natural infection.

In children aged between four and 11 years old, who were not eligible for vaccination, antibody prevalence steadily increased with age at the time of the survey.

The first round of testing for SIS, which is jointly led by the London School of Hygiene & Tropical Medicine (LSHTM), Office for National Statistics (ONS) and UK Health Security Agency (UKHSA), took place between 10 November and 10 December 2021.

Nearly 6,000 students from 117 schools (34 primary and 83 secondary) took part in the COVID-19 antibody testing, of which 3,183 were primary school students and 2,789 secondary school students.

It is great to see that, of those involved in this testing, secondary school pupils have high levels of antibodies, and that nearly half of them were vaccinated at the time of this round."

Dr Patrick Nguipdop Djomo, Study Co-Chief Investigator, London School of Hygiene & Tropical Medicine

"The lower levels of naturally acquired antibodies in primary schools students emphasizes the continued importance of protecting more vulnerable children, family and friends, including getting vaccinated when offered. Thankfully infections in young children remain mild. However, it is uncertain how current antibody levels (whether acquired through infection or vaccination) will protect against future variants. Thus mitigation measures, such as good ventilation in schools, remain important.

"It is also crucial that antibody prevalence in this age group is closely are monitored as they may reflect transmission levels in the community."

Through the first round of SIS 'Headteacher, Parent and Pupil' questionnaires, the team also found that 1% of primary school students and 2.7% of secondary school pupils have experienced long COVID since March 2020.

5.2% of primary school students who tested positive for COVID-19 since March 2020 reported 'loss of taste or smell' for more than 12 weeks, compared to 0.4% of those who had not tested positive. Of pupils aged 11 to 16, 16.6% of those who tested positive had this symptom, compared to 0.4% of those who had not tested positive.

Primary school pupils with long COVID were more likely to present with a probable mental disorder - such as hyperactivity or emotional disorders - than those without long COVID, with 30% of those with long COVID reporting symptoms compared to 7.7% of those without. This trend was also seen in secondary schools, both both results were not statistically significant.

Dr Nguipdop Djomo said: "This data provides important information about the potential direct and indirect impacts of COVID-19 on children and young people, and the support they need during recovery from the pandemic.

"It is reassuring that only a small percentage of students appear to meet the current definition of long COVID in this survey. However, it is a complex condition for which our understanding is rapidly evolving, so the findings should be interpreted with caution.

"Insight into the student's mental health and emotional wellbeing also provides a useful reference point for comparison to pre- and post- pandemic levels, to gauge how this aspect of child health is impacted by the experience of the last two years."

Fiona Dawe, Deputy Director, Wider Surveillance Studies at the ONS, said: "Today's data reveal more about the impact of COVID-19 in primary and secondary school pupils in England.

"We can clearly see the different aspects of children's lives that have been affected by the virus, such as the impact to pupils' emotional well-being.

"This critical information wouldn't be possible without our valued participants and I would like to thank all the schools, parents and pupils involved for their continued support."